SAIN Invasive Plant Pests Resource Collection for: Common Reed
Species (scientific name): Phragmites australis
| Title: Germination response of Phragmites australis and Typha latifolia to diurnal fluctuations in temperature. |
| Author: Ekstam-Borje ; Forseby-Asa. |
| Source: Seed-Science-Research. June, 1999; 9 (2): 157-163. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Germination responses to 45 combinations of diurnal mean temperature and amplitude were examined in freshly collected seeds of two wetland perennials: Typha latifolia L. and Phragmites australis (Cav.) Trin. ex Steudel. Nearly all seeds (> 95%) germinated in favourable temperature regimes. Mean temperature (range 10-30degreeC) and amplitude (range 0-20degreeC) affected final germination of both species. P. australis required a high amplitude (> 10degreeC) for germination over the entire range of mean temperatures. Final germination of T. latifolia was more sensitive to mean temperature than P. australis. The germinated proportion of T. latifolia had a maximum around 20degreeC, above which it decreased, and amplitudes were more stimulating at low than at high levels of mean temperature. The germination rate was rapid and increased with mean temperature for both species. More than 50% germination was achieved within 1-3 d at favourable temperatures. It is proposed that the thermal requirements provide the non-dormant seeds with a season-sensing mechanism which postpones germination of seeds dispersed during autumn, winter or early spring, until the soil surface is heated by the sun in the spring and sufficiently large diurnal fluctuations of temperature occur. Furthermore, the amplitude requirement implies a strong avoidance mechanism for germination of P. australis in sites with small temperature fluctuations (e.g. below water tables), whereas seeds of T. latifolia appear to be less exacting in the requirements when the soil or water becomes warmer. |
| Title: Activity of phase I and phase II detoxication enzymes in different cormus parts of Phragmites australis. |
| Author: Plfugmacher-Stephan ; Geissler-Katja; Steinberg-Christian. |
| Source: Ecotoxicology-and-Environmental-Safety. Jan., 1999; 42 (1) 62-66. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Enzymes of phase I and phase II of the xenobiotic detoxication pathway (ethoxyresorufin-O-deethylase, peroxidases, microsomal and soluble glutathione-S-transferases) were measured in roots, stems, and leaves of Phragmites australis, revealing different enzyme activities in these parts. Highest enzyme activities were measured in the root followed by the leaf. Enzyme activities detected in the stem were low compared with those in the root and leaf. The high detoxication capacity of the root and the leaf might be due to very high exposure to xenobiotics and to the high levels of metabolism in these cormus parts. The function of the stem of Phragmites is mainly transportation, so a high detoxication level is not useful, as indicated by the low enzyme activities. |
| Title: Phragmites australis: Effects of shoot submergence on seedling growth and survival and radial oxygen loss from roots. |
| Author: Armstrong-Jean ; Afreen-Zobayed-Fawzia; Blyth-Sarah; Armstrong-William. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 275-289. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Laboratory experiments indicated that any degree of permanent submergence +40-+120 mm) of young seedling shoots of Phragmites (height: 20-30 mm) greatly reduced (75-100%) the chances of their becoming emergent. With +40 mm submergence and with an absence of algae, about 25% of shoots emerged and grew normally; where algal growth developed during the experiment, 15% of shoots emerged, but where the submerging water was particularly rich in P and algae were present from the onset, no shoots emerged. Seedling leaves which became covered in epiphytic algae lost their chlorophyll. The roots of submerged plants tended to develop more extensive aerenchyma than those of controls whose shoots were emergent. When, after 25 days, water tables were lowered to the soil surface in sand treatments, seedlings recovered quickly except for those from a treatment with dense algal growth. In more mature seedlings (shoot height = 300-400 mm) gradual submergence of shoots in either light or darkness reduced radial oxygen loss (ROL) from adventitious root apices. At 23degreeC there was no ROL at complete submergence in darkness; at 18degreeC the values were from 7-23% of the dark, fully emergent condition. When the lights were switched on, ROL increased almost immediately due to photosynthetic oxygen generation and entrapment in the submerged shoots. At 18degreeC the values attained, relative to the dark emergent condition, were from 42-59%, but at 23degreeC they were much lower: 13-26%. These effects are discussed in relation to the regeneration of Phragmites by the establishment of seedlings, possibly after die-back. |
| Title: Organic acids in the sediments of wetlands dominated by Phragmites australis: Evidence of phytotoxic concentrations. |
| Author: Cizkova-Hana ; Brix-Hans; Kopecky-Jiri; Lukavska-Jaroslava. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 303-315. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Spatial and seasonal variations in concentrations of lower organic acids in the sediments of stands of Phragmites australis (Cav.) Trin. ex Steud. were studied in wetlands in the Czech Republic (Rozmberk fishpond), Hungary (Lake Ferto and Kis-Balaton), and Denmark (Vejlerne Nature Reserve). Pore water concentrations of lactic, formic, acetic, propionic, butyric, oxalic, citric, tartaric, malic and fumaric acid were analysed by HPLC and shown to vary both qualitatively and quantitatively between sites. Acetic acid was prevalent at all sites, and dominated together with citric, malic, and tartaric acid at Rozmberk fishpond, with lactic and oxalic acid at Lake Ferto and Kis-Balaton, and with lactic and propionic acid at Vejlerne Nature Reserve. The maximum total concentrations of organic acids recorded were 2984 and 2215 mumol l-1 at a land and a deep-water site of Rozmberk fishpond, 1673 and 2216 mumol l-1 at a healthy and damaged stand of Lake Ferto, 1006 and 1642 mumol l-1 at ahealthy and damaged stand of Kis-Balaton, and 570 and 223 mumol l-1 at a healthy reed stand and a lagoon at Vejlerne Nature Reserve, respectively. At Rozmberk fishpond the concentrations of lower organic acids were considered sufficiently high to diminish the plants vigour and possibly to induce die-back. At Lake Ferto and Kis-Balaton the organic acids are unlikely to have had a toxic effect on the reeds at the sampling time because of the relatively high pH (apprx7) in these wetlands. However, because of the great spatial and seasonal variability in organic acid speciation and concentration, organic acid phytotoxity may affect the reed also at these sites. At Vejlerne Nature Reserve, the toxic effect on the reeds is unlikely because of consistently low concentrations of organic acids. |
| Title: Nitrogen and carbohydrate storage in rhizomes of Phragmites australis (CAV.) TRIN. ex STEUDEL at different aquatic sites of lakes in Upper Bavaria. |
| Author: Pohl-Wolfgang; Grosser-Stephan; Melzer-Arnulf. |
| Source: Limnologica-. Jan., 1999; 29 (1) 36-46. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Nitrogen and carbohydrate utilization in Phragmites australis rhizomes was investigated under natural conditions at 10 sites in 5 lakes in Upper Bavaria over a period of two years. Nitrate and ammonium of surface and interstitial water was determined. The results indicate that conditions of habitat and environment, such as climate and fluctuation of water level, lead to different adaptations of reed. These parameters had an effect on the storage of nitrogen and carbohydrate. The reed stands exposed to high water level during spring and summer have a high carbohydrate content in the rhizomes. A positive correlation was shown between the aboveground biomass and the content of storaged carbohydrates during the vegetation period. No relationship could be demonstrated between the nitrogen availability of the habitats and the type of storage of carbohydrates and nitrogen. The nitrogen content in the rhizomes can be used as an indicator of the ability of reed stands to produce new secondary shoots after shoot loss. The differently established reed genotypes are not able to compensate short-term environmental changes, such as growing leisure problems and higher shoot loss by the increasing appearance of waterfowl, from their reserve storage. |
| Title: Phenotypic differences among ploidy levels of Phragmites australis growing in Romania. |
| Author: Pauca-Comanescu-Mihaela ; Clevering-Olga-A; Hanganu-Jenica; Gridin-Mihai. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 223-234. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: This paper presents data showing phenotypic differences of Phragmites australis (Cav.) Trin. ex Steud. (Common reed) growing in Comana lake and in the Danube Delta (Romania). In Comana lake, tetra- and octoploids were found, whereas in the Danube Delta also hexaploids occurred. In freshwater habitats, shoots of octoploids were longer and thicker with more nodes than those of tetraploids. Panicles of octopoids were also larger than those of tetraploids. The number of alive leaves did not differ between ploidy levels. Total leaf area, however was higher of octo- than of tetraploids, which indicates that octoploids produced larger leaves. Octoploids also had thicker rhizomes. No differences in allocation of dry matter to leaves, stems, and leaves (blades and sheaths) were found between tetra- and octoploids. Both tetra- and octoploids shoots were among the tallest in the central Danube Delta. Tetraploids were morphologically more diverse in Comana lake than in the central Danube Delta.Within areas, size of shoots could, however, not be related to water depth. Salinity reduced shoot size of tetraploids considerably. Under saline conditions, no differences in morphology of shoots were found between tetra- and hexaploids. |
| Title: Isozyme variation among populations of the clonal species, Phragmites australis (Cav.) Trin. ex Steudel. |
| Author: Pellegrin-Dana; Hauber-Donald-P. |
| Source: Aquatic-Botany. April, 1999; 63 (3-4) 241-259. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Few studies have examined population genetic variation in clonal, emergent, aquatic plant species. Phragmites australis (Cav.) Trin. ex Steudel is a clonal, cosmopolitan species common to marshes, estuarine, and other wetland habitats. With the exception of several European studies examining local variation, little is known about the distribution of genetic variation in this taxon, particularly in the U.S. In recent years, the rapid and invasive, vegetative spread of P. australis into disturbed marsh habitats in the U.S., particularly on the Eastern Seaboard and the Mississippi River delta, has sparked interest in its ecology and genetic structure. In this study, electrophoresis was used to analyze isozyme variation among 37 populations of P. australis from the eastern half of the U.S. The electrophoresis data strongly support a primarily vegetative mode of reproduction and spread. A total of 21 multilocus, isozymic phenotypes were identified among the 37 populations. All populations sampled along the Gulf Coast (GC) from Texas to the Florida panhandle (with the exception of the two populations from the Mississippi River delta) were uniform, sharing a single, multilocus phenotype. P. australis populations had lower levels of percent polymorphic loci and number of alleles per locus than typical asexual terrestrial species, but had a higher mean heterozygosity. Nei's genetic distance UPGMA depicts a substantial amount of geographic clustering of populations. However, populations described as 'invasive' showed no genetic similarity to one another. |
| Title: Iron oxidation states on root surfaces of a wetland plant (Phragmites australis). |
| Author: Wang-Tiangen ; Peverly-John-H. |
| Source: Soil-Science-Society-of-America-Journal. Jan.-Feb., 1999; 63 (1) 247-252. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Iron in root plaque is usually thought to be Fe(III) because of rhizosphere oxidation. This study was conducted to examine Fe oxidation states on root surfaces of the common reed (Phragmites australis (Cav.) Trin. ex Steudel). Using an EDTA-BPDS method, Fe(II) and Fe(III) on the surfaces of roots sampled from various environments were stabilized, extracted and determined simultaneously. The proportion of extracted Fe(II) to total Fe ranged from 0.17 to 0.65 for the roots grown in constructed wetlands, fields, and hydroponic culture; and from 0.34 to 0.70 for different sections of wetland plant roots. The observed results suggested that Fe plaque is caused not only by rhizosphere oxidation, but also by Fe(II) compound formation on the root surfaces. |
| Title: Interactive effects of N and P on growth, nutrient allocation and NH4 uptake kinetics by Phragmites australis. |
| Author: Romero-Jose-Antonio; Brix-Hans; Comin-Francisco-A. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 369-380. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: The interactive effects of three levels of NH4-N (50, 500 and 1000 mumol l-1) and two levels of phosphate (15 and 50 mumol l-1) on growth, nutrient allocation and ammonium uptake kinetics by Phragmites australis (Cav.) Trin. ex Steudel were studied in hydroponic culture in the laboratory. Nitrogen level in the root solution significantly affected the relative growth rate of the plants, the rate being lower at low N (0.026 per day) than at intermediate (0.035 per day) and high N (0.037 per day), but phosphorus did not significantly affect growth. The N : P ratio in the root solution significantly affected the growth rate which was highest at N : P ratios between 10 and 33 on a molar basis. Nitrogen and phosphorus concentration in the plant tissues generally increased with N level in the root solution, but P level had no effect. Plant tissue N : P ratios (on a molar basis) varied between 13.5 in the stems to 28.0 in the leaves and were unaffected by the treatments. Ammonium uptakekinetics were unaffected by N treatment, but Vmax was significantly affected by P treatment averaging (mean +- 95% confidence limits (CL)) 151 +- 44 mumol g-1 root dry weight h-1 in the low-P treatment and 229 +- 70 mumol g-1 root dry weight h-1 in the high-P treatment. The overall mean (+-95% CL) NH4-N uptake kinetic parameters were: Vmax = 190 +- 20 mumol g-1 root dry weight h-1; K1/2 = 21.8 +- 1.8 mumol l-1, and Cmin = 1.2 +- 0.2 mumol l-1. Mean (+-SD) root respiration rate was 72 +- 22 mumol CO2 g-1 dry weight h-1 and was unaffected by the treatments. The results of the study support the general hypothesis that P. australis is well-adapted for growth in nutrient-rich habitats. However, P. australis is able to acclimate to low nutrient availability by increasing the affinity for ammonium uptake. |
| Title: Interactive effects of N and P on growth, nutrient allocation and NH sub(4) uptake kinetics by Phragmites australis. |
| Author: Romero,-J.A.; Brix,-H.; Comin,-F.A. |
| Source: Aquatic-Botany [Aquat.-Bot.] 1999 vol. 64, no. 3-4, pp. 369-380. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Special Issue: Genetic diversity, ecophysiology and growth dynamics of the common reed (Phragmites australis). The interactive effects of three levels of NH sub(4)-N (50, 500 and 1000 mu mol l super(-1)) and two levels of phosphate (15 and 50 mu mol l super(-1)) on growth, nutrient allocation and ammonium uptake kinetics by Phragmites australis (Cav.) Trin. ex Steudel were studied in hydroponic culture in the laboratory. Nitrogen level in the root solution significantly affected the relative growth rate of the plants, the rate being lower at low N (0.026 per day) than at intermediate (0.035 per day) and high N (0.037 per day), but phosphorus did not significantly affect growth. The N:P ratio in the root solution significantly affected the growth rate which was highest at N:P ratios between 10 and 33 on a molar basis. Nitrogen and phosphorus concentration in the plant tissues generally increased with N level in the root solution, but P level had no effect. Plant tissue N:P ratios (on a molar basis) varied between 13.5 in the stems to 28.0 in the leaves and were unaffected by the treatments. Ammonium uptake kinetics were unaffected by N treatment, but V sub(max) was significantly affected by P treatment averaging (mean plus or minus 95% confidence limits (CL)) 151 plus or minus 44 mu mol g super(-1) root dry weight h super(-1) in the low-P treatment and 229 plus or minus 70 mu mol g super(-1) root dry weight h super(-1) in the high-P treatment. The overall mean ( plus or minus 95% CL) NH sub(4)-N uptake kinetic parameters were: V sub(max) = 190 plus or minus 20 mu mol g super(-1) root dry weight h super(-1); K sub( one half ) = 21.8 plus or minus 1.8 mu mol l super(-1), and C sub(min) = 1.2 plus or minus 0.2 mu mol l super(-1). Mean ( plus or minus SD) root respiration rate was 72 plus or minus 22 mu mol CO sub(2) g super(-1) dry weight h super(-1) and was unaffected by the treatments. The results of the study support the general hypothesis that P. australis is well-adapted for growth in nutrient-rich habitats. However, P. australis is able to acclimate to low nutrient availability by increasing the affinity for ammonium uptake. |
| Title: Insects on common reed (Phragmites australis): Community structure and the impact of herbivory on shoot growth. |
| Author: Tscharntke-Teja. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 399-410. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: In this paper, community structure of endophagous insects attacking common reed (Phragmites australis (Cav.) Trin ex Steud.) and impact of herbivory on shoot growth was analyzed in south west Germany. All the 26 phytophagous insects were monophagous, i.e. restricted to their host plant P. australis, which appeared to be due to the predictability and apparency of the large and ancient Phragmites stands. Habitat types were clearly separated due to the mean shoot diameter ('dry' and 'wet' reed) and the mean level of shoot damage (high and low abundance of Archanara shoots). The stem-boring moth Archanara geminipuncta greatly influenced structure of the insect community, due to heavy shoot damage, and could be classified to be the key species of the reed ecosystem. In contrast to common expectations of negative effects, Archanara shoot damage enhanced populations of many insect species, so insect guilds of 'primary attackers' (on the main shoot) and 'secondary attackers' (on damaged shoots) could be separated. Primary attackers either killed the growing point or attacked the apical, medium or basal internodes, while secondary attackers were facilitated by shoot damage and could also be subdivided in four guilds: Inquilinous species living between the wilting leaves of damaged shoots, attackers of the side shoot growing in response to the destruction of apical meristems, saprophagous species feeding on Archanara droppings, and the successor community of bees and wasps nesting in empty galls or broken shoots. There is a continuum from evident plant damage, e.g. by stem-boring moths and leaf-sucking aphids, to enhanced shoot growth due to the parasitic influence of gall makers, e.g. the significant shoot elongation by the gall midge Giraudiella inclusa. In Europe, conservationists are concerned about the die-back of P. australis, while in North America and Australia, P. australis is considered to be an invasive weed. Classical biological control with the introduction of European insects (like the moth A. geminipuncta) is discussed. |
| Title: Analysis of genetic diversity among selected populations of Phragmites australis world-wide. |
| Author: Koppitz-Heike. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 209-221. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Genetic diversity among reed (Phragmites australis) populations from 70 sites in Europe and from 12 sites in other continents was determined using the random amplified polymorphic DNA (RAPD) technique. Based on results from about 1000 reed samples screened with different primers, both polyclonal reed stands, where different clones co-exist either next to each other or intermingle, and monoclonal reed stands were found. Generally a higher diversity of clones was detected from sites on or near shore than in the water. Cluster analysis of genetic similarity coefficients from 30 to 80% demonstrated a high degree of genetic diversity among reed stands world-wide. Lower genetic diversity was detected among samples from any location, with coefficients ranging from 70 to 100%. In general, the genetic distances of investigated reed samples within Europe increase with increasing geographic distances. The reed samples from the other continents formed a separate major cluster in the phenogram. |
| Title: Distribution of the aphid Hyalopterus pruni GEOFFR. within and between habitats of common reed Phragmites australis (CAV.) TRIN. ex STEUDEL as a result of migration and population growth. |
| Author: Mook-Jaap-H ; Wiegers-Jaap. |
| Source: Limnologica-. Jan., 1999; 29 (1) 64-70. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: The aphid Hyalopterus pruni migrates to its secondary host Common Reed in late spring and early summer. Reed fields are known to be more heavily infested at the edges compared to the centre, as the migrants are attracted to the colour of the reed. There is also evidence that reeds growing at wet sites are more heavily infested than at dry sites. This paper shows that both processes interact in determining the distribution of aphids in different habitats. The observations were carried out in the vast reed field of the Zuidelijk Flevoland polder (The Netherlands) during a number of years after its reclamation in 1968. In the period of migration flying aphids were caught with sticky traps situated in and around the reed field. The distribution of aphids on the reed was determined at different times during the season along transects through the centre of the polder. The existence early in the season (June) of a higher infestation at the edges than in the centre of the field was confirmed. The density of winged aphids in this early period was higher in wet than in dry habitats, which may have been a result of a preference of the settling migrants for reed standing in water. Later in the season (August) the dry habitat still had a relatively low infestation in the centre, but at the wet sites the infestation was high everywhere. This could be attributed to the much quicker population growth that was found in the wet habitat and subsequent short range movement of newly born winged aphids. |
| Title: Distribution of the invasive reed Phragmites australis relative to sediment depth in a created wetland. |
| Author: Pyke-Christopher-R ; Havens-Kirk-J. |
| Source: Wetlands-. March, 1999; 19 (1): 283-287. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: This study collected new data on sediment thickness and distribution and integrated it with existing data on the distribution of plant species within a small (0.5 ha) created, tidal salt marsh in Langley, Virginia, USA. The presence of the reed Phragmites australis was found to be inversely correlated with sediment accumulation on the marsh surface. Sediment-deficient areas seem at a higher risk for invasion by P. australis and subsequent loss of designed marsh habitat. The results indicate that areas of low sediment accumulation may be used as a proxy measure for areas vulnerable to invasion. These areas can be easily delimited both in the field and on aerial photography. |
| Title: Responses of ecotypes of Phragmites australis to increased seawater influence: A field study in the Danube Delta, Romania. |
| Author: Hanganu-Jenica ; Mihail-Gridin; Coops-Hugo. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 351-358. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: The effects of locally increased salinity in a complex of Fine and Giant reed (Phragmites australis) clones were investigated in the Tataru channel (Danube Delta, Romania). Following digging of the Tataru channel, the area closest to the sea became isolated from freshwater input, causing saline conditions to develop due to its proximity to the sea. The other side of the channel remained a freshwater area. The impact of increased salinity on the regression of reed was studied and related to a possible difference in susceptibility to high salt concentrations between different clones (Octoploid Giant reed versus Tetraploid Fine reed). Measurements were made in survey plots situated on both sides of the channel. In freshwater, Giant reed had higher and thicker shoots than Fine reed, but stem density was much smaller, resulting in a lower biomass per surface area of Giant reed. Growth of both Giant and Fine reed was severely reduced at the saline east side of the channel. A significant interaction was found between reed type and salinity. Giant reed density, height, stem diameter and biomass were more strongly affected by saline conditions than Fine reed. The salinization of the parts east of the channel might thus have affected Giant reed stands more strongly than Fine reed stands. The implications for reed succession under increased salinity in the delta are discussed. |
| Title: Bank protection using common reed (Phragmites australis). |
| Author: Coops-Hugo. |
| Source: Levende-Natuur. Feb., 1999; 100 (2): 46-49. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Wave action is an important factor in the degradation of reedbelts. This can be due to both an indirect impact, such as the sorting of sediments in the shore zone, and to a direct impact, i.e. bending and breaking of stems and washing out of plants. Among other parameters, strength and flexibility of individual stems determine the erosion susceptibility of a reed stand. Measures taken to prevent damage to reed stands often target on excluding wave action by any sort of protective construction, or for instance limitation of speed for passing boats. There are still many questions to be answered to provide a clear view on the restoration potential of littoral reed stands, concerning: 1) the strength of reed stands to withstand erosion and other environmental impacts, 2) the application of different ecotypes of reed, and 3) the effects of water-level alterations on reed performance. |
| Title: Clone specific differences in a Phragmites australis stand I. Morphology, genetics and site description. |
| Author: Kuehl-Harald ; Koppitz-Heike; Rolletschek-Hardy; Kohl-Johannes-Guenter. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 235-246. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: A selected reed stand (Phragmites australis) at a shallow lake near Berlin was investigated from 1992 to 1995. This reed stand is clearly divided into four visually distinguishable clusters. The study focuses on the clonal distribution within the whole reed stand in relation to morphological characteristics. Furthermore, it should be proved if the clustered stand structure is caused by different site conditions. Genotypic variability was detected by using the RAPD-technique. The parameters shoot length, leaf area, number of internodes and leaves, diameter of culms, shoot density and percentages of shoots with panicles were measured once a year at the end of the vegetation period. The concentrations of ammonium, nitrate, nitrite, o-phosphate and sulphate in interstitial water and sediment extracts were determined. Four adjacent clones were found, which showed differences in morphology. These differences in shoot architecture were observed in spite of uniform site conditions. This suggests a large clonal difference in expression of morphological features. First conclusions are drawn regarding the relationship between genotypes within a reed stand and the expression of morphological characteristics. |
| Title: Clone specific differences in a Phragmites australis stand II. Seasonal development of morphological and physiological characteristics at the natural site and after transplantation. |
| Author: Rolletschek-Hardy ; Rolletschek-Alexandra; Kuehl-Harald; Kohl-Johannes-Guenter. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 247-260. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Two Phragmites clones, growing adjacent to each other but differing conspicuously in stand structure, were investigated in 1996 regarding seasonal change in morphological and physiological parameters. Both clones showed significant differences in shoot morphology (length, diameter, dry weight, leaf area), maximum above-ground (420 versus 152 g DW m-2) and below-ground biomass (2.4 versus 1.5 kg DW m-2). Furthermore, physiological parameters (N concentration, N and P content per shoot and m2, content of dissolved amino acids, N translocation rate) varied between clones in their time course. Clone-specific variations in these characteristics were significant even after transplantation to another field site. Overall, these results suggest that the distinct growth forms and levels of productivity of the two Phragmites clones are the result of genotypic variation. It is hypothesized that both clones follow distinct ecophysiological strategies causing their morphotypic differentiation. Implications of genotypic determination of growth forms are discussed in relation to nutrient supply, N limitation, population plasticity, eutrophication and reed regression. |
| Title: Controls on soil cellulose decomposition along a salinity gradient in a Phragmites australis wetland in Denmark. |
| Author: Mendelssohn-Irving-A ; Sorrell-Brian-K; Brix-Hans; Schierup-Hans-Henrik; Lorenzen-Bent; Maltby-Edward. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 381-398. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Although soil organic matter decomposition is an important process determining nutrient transformations and availability in wetland ecosystems, few studies have attempted to assess which environmental factors are most important in controlling spatial differences in decomposition rates found along environmental gradients. Relative soil decomposition was determined in a Phragmites australis Cav. Trin ex Steudel dominated wetland in northern Jutland, Denmark along a natural salinity gradient, where nutrients, soil moisture, temperature and salinity among other factors also varied. Our objective was to identify which edaphic factors most limited rates of relative soil decomposition, as evaluated by measuring cellulose decomposition with the cotton strip technique. Replicate cotton strips were placed at seven marsh sites along the salinity gradient, and soil and interstitial water samples were collected and analyzed for major macro- and micronutrients (NH4-N, NO3-N, P, PO4, K, Mg, Ca,Na, S, Fe, Mn, Zn, Cu, Mo, B, Si), pH, Eh, conductivity, temperature, and soluble sulfides. Cellulose decomposition, expressed as cotton tensile strength loss (CTSL) per day, decreased with increasing salinity, except at the highest salinity site where a significant increase occurred. Mean CTSL values, averaged for each marsh site, varied 3-fold from 1.8 to 5.5% loss per day. Principal component and multiple regression analyses were used to prioritize the importance of the various factors that might control this spatial difference in CTSL rates. Although soil conductivity (salinity) accounted for the large percentage (45%) of the variation in the environmental data, soil fertility- and soil reduction-associated variables explained the greatest percentage (56%) of the spatial variation in cellulose decomposition. Univariate correlation analyses supported the conclusion that soil fertility, primarily inorganic nitrogen and phosphorus, is the major environmental factor determining soil cellulose decomposition rates along this salinity gradient. |
| Title: Carbohydrate storage in rhizomes of Phragmites australis: The effects of altitude and rhizome age. |
| Author: Klimes-Leos ; Klimesova-Jitka; Cizkova-Hana. |
| Source: Aquatic-Botany. June, 1999; 64 (2): 105-110. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Starch, glucose, fructose and sucrose were measured in nodes and internodes of horizontal rhizomes of Phragmites australis in two localities, at 400 and 1350 m above sea level respectively, before spring growth started. In the respective localities, five and four age categories of rhizomes were distinguished. Rhizomes of lowland plants, harvested on March 21, contained more starch (17.6%), glucose (2.5%) and total non-structural carbohydrates (35.2%) per gram dry mass than rhizomes of plants collected at the tree line on June 3 (11.8, 1.7 and 30.5%, repectively). The proportion of water soluble carbohydrates to total non-structural carbohydrates, as an indication of acclimatisation to a cold climate, was higher in the mountain locality (60 and 49%, respectively). Glucose and starch concentrations increased with rhizome age in both localities. All other carbohydrate fractions were independent of locality. Water soluble carbohydrates were preferentially accumulated in internodes whereas starch was accumulated in nodes. |
| Title: Carbohydrate and nutrient content in rhizomes of Phragmites australis from different habitats of Lake Ferto/Neusiedlersee. |
| Author: Dinka-Maria ; Szeglet-Peter. |
| Source: Limnologica-. Jan., 1999; 29 (1) 47-59. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Changes in the soluble sugar, starch, total non-structural carbohydrate (TNC) and nutrient (N, P, K) concentration in the reed rhizome were investigated in different reed habitat types in Lake Ferto/Neusiedlersee during the vegetation period in 1993 to 94. Three die-back and four vigorous reed stands were monitored. For biomass estimations rhizomes were collected twice. in early summer and in autumn. They were calculated to be 1.9 to 2.7 kg/m2 at die-back and 3.1 to 6.1 kg/m2 at vigorous sites. The carbohydrate and nutrient concentrations of the reed rhizomes were high at the beginning of the vegetation period; they reached their minima in May-June, which was followed by a gradual increase until the end of the vegetation period. From autumn to spring the concentrations decreased, e.g. TNC concentration by 15 to 40% at vigorous, 50 to 70% at die-back sites. In both years the lowest carbohydrate concentrations were recorded at the end of May, a month before the inflorescence developed (vigorous sites: 50-70 mg TNC/g, die-back sites: 70-120 mg TNC/g). In that period the standing stock of the TNC in the rhizome did not separate the sites clearly, and the smallest carbohydrate standing stock was measured at a vigorous site with a high water cover. At the beginning of summer and in autumn the soluble sugar, TNC and N concentration values were higher at the die-back than at the vigorous sites but the standing stock was higher at the vigorous sites. In autumn the TNC standing stock of the rhizomes was between 780 and 1200 g/m2 at vigorous, between 380 and 690 g/m2 at die-back sites. This is especially important for the reactions and resistance of die-back reed stands to unfavourable conditions. |
| Title: Growth and photosynthetic performance of Phragmites australis in estuarine waters: A field and experimental evaluation. |
| Author: Adams-J-B ; Bate-G-C. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 359-367. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Surveys of South African estuaries showed that in estuaries that had a gradient of decreasing salinity up the length of the estuary salt marshes occurred near the saline middle-lower reaches and reeds and sedges in the brackish upper reaches. However, in certain estuaries common reed Phragmites australis occurred in the lower reaches of estuaries. The plants often extend into the intertidal zone where they are inundated with saline water (35 ppt). This study tested whether P. australis occurred at these sites because its roots were located in fresh or brackish water. In P. australis stands in the Goukou and Keurbooms estuaries interstitial water salinity was lower than surface water salinity. There was an increase in interstitial salinity towards the water's edge and this was associated with a decrease in the height of P. australis. Laboratory studies tested whether P. australis could survive tidal inundation with saline water (35 ppt) if its roots and rhizomes were located in freshwater (0 ppt). Plants which were supplied with freshwater to the roots but were tidally inundated with saline water had greater stem elongation and less dead leaves than plants that were supplied with 20 ppt salinity to the roots. P. australis will probably only survive intertidal flushing with saltwater if its roots and rhizomes are located in brackish water (<20 ppt). This accounts for the presence of P. australis in saline estuaries at the sites of freshwater seepage. |
| Title: Does the common reed, Phragmites australis, affect essential fish habitat? |
| Author: Weinstein-Michael-P ; Balletto-John-H. |
| Source: Estuaries-. Sept., 1999; 22 (3B): 793-802. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Since the early 1900s Phragmites australis has been replacing other vegetation in Atlantic and Gulf coast marshes at a rate of about 1% to 6% of the marsh surface per year. Vast areas of coastal marsh are now characterized by dense monotypic stands of this species. By virtue of its ability to build up the marsh surface, P. australis affects the landscape, hydrology, and hydroperiod of the marsh as well as drainage density, and other geomorphic features. Smoothed microtopography results in more difficult access to the marsh by nekton, and possibly reduced exchange of organic materials between the marsh and adjacent estuary. The pattern of replacement by P. australis results in fragmentation of existing stands of Spartina alterniflora and other extant macrophytes, thereby altering landscape ecology and the ability of the marsh to support biodiversity and the production of marsh fauna. |
| Title: Taxonomy, chromosome numbers, clonal diversity and population dynamics of Phragmites australis. |
| Author: Clevering-Olga-A ; Lissner-Jorgen. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 185-208. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Phragmites australis (Cav.) Trin. ex Steud. (common reed) is one of the most widespread plant species in the world. The species has a high phenotypic variation in morphology and life-history traits. This high phenotypic variation can be related to variance in chromosome numbers, clonal diversity, plasticity of clones or a combination of these. An overview of our present, still limited, knowledge concerning the amounts, causes and maintenance of genetic diversity in P. australis is given. In P. australis a large range in euploid number has been found (between 3x-12x, except for 5x and 9x, with x = 12). In Europe tetraploids are dominant, whereas octoploids predominate in Asia. Aneuploids also occur regularly in P. australis, and differences in chromosome numbers have been observed even within clones. Clonal diversity in P. australis has been studied using allozyme polymorphisms and molecular markers. Both mono- and polyclonal stands are known to exist. A surprisingly high number of clones has been found in European stands. Environmental and genetic factors, which may account for this high clonal diversity, are discussed. In most studies on the occurrence of ecotypes in P. australis no distinction has been made between plastic and genetic variation. But evidence exists that responses to climate, hydrology and salt have a genetic basis. Until now no attempts have been made to determine which genes or gene complexes are responsible for these different responses. |
| Title: Ecological and molecularbiological investigations on reed (Phragmites australis (CAV.) TRIN. ex STEUDEL) in lakes of Northern Germany - An overview. |
| Author: Schieferstein-Barbara-B. |
| Source: Limnologica-. Jan., 1999; 29 (1) 28-35. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: The structure, function and dynamics of reed-belts from three 'Bornhoeved-Lakes' was investigated by using methods from vegetation science and molecular biology. Between 1992 and 1994 the morphometry and production of Phragmites was measured at twelve locations, differing in sedimentology and hydrochemistry. The development and production of the plants, as well as the nutrient uptake and relocation, were similar throughout the years within each of the twelve plots. Differences in stand-structure and amounts of nutrients occurred between the habitats. Nitrogen content in the plant material varied between 5 and 30 g N m-2 and phosphorus between 0.3 and 1.2 g PO4-P m-2. 80 natural reed habitats were measured for Restriction Fragment Length Polymorphisms (RFLPs) in order to identify the genetic diversity of Phragmites within the lakes. A cluster analysis exhibited groups with high, as well as groups with low genetic similarity. Even if genetically similar, the habitats were not necessarily directly neighboured at the shoreline. A discriminance analysis showed 40% correspondence of the genetic groups with their phenotype and habitat parameters. |
| Title: Effect of climate on the salt tolerance of two Phragmites australis populations. I. Growth, inorganic solutes, nitrogen relations and osmoregulation. |
| Author: Lissner-Jorgen ; Schierup-Hans-Henrik; Comin-Francisco-A; Astorga-Val. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 317-333. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: This study estimated the effects of Danish (temperate nemoral) and Spanish (mediterranean) climatic conditions on the salt tolerance of two Phragmites australis (Cav.) Trin. ex Steud. populations. Plants propagated from seeds collected in Denmark (=Danish population) and Spain (=Spanish population) were exposed to salinity levels ranging from 0 to 30permill at outdoor experimental plots situated in Denmark (56degreeN) and Spain (41degreeN). Plants were measured for growth rate, mortality, below-ground/above-ground ratio, water content, ash content, nitrogen content, C:N and ions (K+, Na+, Mg2+, Ca2+, Cl-). Growth was significantly enhanced at the Spanish growth site, especially for salinity levels ranging from 10 to 20permill. In this interval, growth rates of both the Danish and the Spanish population were 20-100% higher than at the Danish growth site. These growth data point to higher salt tolerance at the Spanish site when using relative salt tolerance and absolute salt tolerance as criteria. Salt tolerance is ascribed to two important mechanisms, cation adjustment and water loss. Despite higher transpiration at the Spanish site, plants were able to maintain or improve K+/Na+ ratios of leaf laminas, indicating enhanced cation adjustment under the Spanish climatic conditions. Primarily, this was due to higher K+ accumulation at the Spanish site (305-378 mmol kg-1) as compared to the Danish site (220-268 mmol kg-1), while a climatic effect on Na+ level only was evident for the Danish population. Climatically induced differences in water content may also have contributed significantly to the higher salt tolerance observed for plants at the Spanish site. Shoot water content was lower at the Spanish site (1.9-2.4 g water g-1 DW) than at the Danish site (2.6-4.0 g water g-1 DW), suggesting that water loss is an important mechanism contributing to osmotic adjustment. Water loss may act by concentrating solutes in the cell sap, thereby reducing the need for synthesis of metabolically expensive organic osmotica as well as reducing the need for Na+ uptake for osmotic adjustment. This study also showed that P. australis populations differ in salt tolerance. A relatively higher salt tolerance observed for the Danish population was related to lower mortality, lower leaf Na+ and Cl- content, higher leaf K+/Na+ ratio, higher leaf nitrogen content, higher below-ground/above-ground ratio and lower ash content of below-ground parts and is discussed in relation to partitioning. |
| Title: Effect of climate on the salt tolerance of two Phragmites australis populations. II. Diurnal CO sub(2) exchange and transpiration. |
| Author: Lissner,-J.; Schierup,-H.-H.; Comin,-F.A.; Astorga,-V. |
| Source: Aquatic-Botany [Aquat.-Bot.] 1999 vol. 64, no. 3-4, pp. 335-350. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Special Issue: Genetic diversity, ecophysiology and growth dynamics of the common reed (Phragmites australis). This study examined the effects of salinity and climate on instantaneous CO sub(2) exchange rates and daily carbon balance for two populations of Phragmites australis. Plants propagated from seeds collected in Denmark (=Danish population) and Spain (=Spanish population) were grown at salinities of 0, 5 and 10% at outdoor experimental plots situated at a nemoral growth site (Denmark, 56 degree N) and at a mediterranean growth site (Spain, 41 degree N). In situ measurements of shoot CO sub(2) exchange were made under different meteorological conditions. Maximum CO sub(2) uptake rates were 24 and 19 mu mol m super(-2) s super(-1) in Spain and Denmark, respectively, and were only reached under conditions of full sunlight. On sunny days, CO sub(2) uptake was reduced less by salinity at the Spanish site than at the Danish site. Photosynthetic photon flux densities saturating shoot photosynthesis were much lower in Spain (ca. 600 mu mol m super(-2) s super(-1)) as compared to those in Denmark (ca. 1300 mu mol m super(-2) s super(-1)). This affected the period of maximum CO sub(2) uptake rates which was 2-3 h longer at the Spanish growth site, despite shorter day length at this site (15 h) than at the Danish site (17 h). |
| Title: Expansion of Phragmites australis into tidal wetlands of North America. |
| Author: Chambers-Randolph-M ; Meyerson-Laura-A; Saltonstall-Kristin. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 261-273. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Phragmites expansion into tidal wetlands of North America is most extensive along the northern and middle Atlantic coasts, but over 80% of the US coastal wetland area occurs along the Gulf of Mexico and southern Atlantic coasts and may be susceptible to ongoing expansion. Rapid spread of Phragmites has been documented in freshwater (<0.5 ppt), oligohaline (0.5-5 ppt) and mesohaline (5-18 ppt) tidal wetlands. The advance of Phragmites into tidal wetlands of North America may have been facilitated by widespread coastal changes since European settlement, including disturbance of hydrologic cycles and nutrient regimes; the presence of Phragmites has become a signature of tidal wetland alteration. Although ploidy levels from 2n = 36 to 72 have been documented for Phragmites throughout the continent, no genetics research to date has tested whether recent introduction of aggressive clones could account for Phragmites expansion. A fundamental concern regarding Phragmites expansion, particularly into tidal freshwater wetlands, is the observed reduction in biodiversity as many native species of plants are replaced by a more cosmopolitan species. Commensurate with a shift in habitat type is a reduction in insect, avian and other animal assemblages. Ecosystem services, including support of higher trophic levels, enhancement of water quality and sediment stabilization, however, are not diminished when a tidal wetland becomes dominated by Phragmites, provided that tidal flooding is retained. |
| Title: Genetic diversity, ecophysiology and growth dynamics of reed (Phragmites australis). |
| Author: Brix,-H. |
| Source: Aquatic-Botany [Aquat.-Bot.] 1999 vol. 64, no. 3-4, pp. 179-184. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Special Issue: Genetic diversity, ecophysiology and growth dynamics of the common reed (Phragmites australis). The common reed, Phragmites australis (Cav.) Trin ex Steudel, is among the most widespread and productive plant species in the world, and is one of the few species that can truly be regarded as cosmopolitan. It is a robust, perennial emergent aquatic plant up to 6 m high, belonging to the family Poaceae. The annual stems develop from a system of vertical and horizontal perennial rhizomes that also function in the vegetative spread of the plant. P. australis usually forms dense, nearly monospecific stands in littoral zones of lakes, along rivers and irrigation/drainage canals and in shallow, freshwater swamps. Its geographical distribution extends from cold temperate regions to the tropics. Some of the largest Phragmites-dominated ecosystems in the world are found in Europe (e.g., the Danube Delta and Lake Ferto), where the stems of the reeds have been used for centuries for roofing and fencing. Phragmites also plays an important role in preventing wave and current erosion of river and lake banks, and in providing a habitat for wild fowl and other fauna. Many bird reservations are wetlands in which P. australis is the dominant species. These areas have a great economic value for tourism (bird watching and hunting) and often support fisheries of local importance. It is, therefore, not surprising that P. australis is one of the most extensively studied wetland species in the world. |
| Title: Methanogenesis and methane emissions: Effects of water table, substrate type and presence of Phragmites australis. |
| Author: Grunfeld-Simon; Brix-Hans. |
| Source: Aquatic-Botany. May, 1999; 64 (1): 63-75. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Effects on methanogenesis and CH4 emission of three water table positions, sediment composition and presence or absence of the emergent macrophyte Phragmites australis (Cav.) Trin. Ex Steud. were studied in outdoor experimental mescosms. Water table position significantly affected methanogenesis and CH4 emission, the rates being 40% and 60% lower, respectively, in vegetated organic sediments with a water table 22 cm below the surface as compared with vegetated inundated sediments. Due to the high water-holding capacity of organic sediments, rates of methanogenesis and CH4 emission in organic sediments with a water table 8 cm below the sediment surface were only slightly, but not statistically significantly different from rates in inundated sediments. Sandy sediments with water tables 8 cm below the sediment surface had very low methanogenic activity as compared with organic sediments (1 versus 55 mmol m-2 per day). The presence of P. australis in inundated sediments attenuatedthe rate of methanogenesis by 27%, enhanced the proportion of CH4 oxidised from 7% to 118%, and as a result attenuated CH4 emission by 34%. In vegetated sediments CH4 emission peaked at midday and was longest during the night and early morning in concert with the diurnal changes in internal convective flow in the plants. Internal gas transport through the plants accounted for 62% of the CH4 emitted from vegetated sediments while ebullition dominated in unvegetated sediment. |
| Title: Biometric variation in Phragmites australis affecting convective ventilation and amino acid metabolism. |
| Author: Rolletschek-Hardy ; Hartzendorf-Thomas; Rolletschek-Alexandra; Kohl-Johannes-Guenter. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 291-302. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Parameters of convective ventilation and amino acid patterns in basal culm internodes of Phragmites australis (Cav.) Trin. ex Steud. were studied at four sites in the Danube Delta (Romania) in May 1997. The considerable stand-specific differences in shoot diameter, length and density were related to ventilation efficiency. Tall shoots with high diameters were able to induce higher gas flow rates per generated pressure differential, than those with smaller diameters. However, if the flow rates of single culms were related to the corresponding shoot densities, stands with thinner shoots but higher densities achieved significantly higher ventilation efficiencies per m2 reed stand. These differences in the rate at which rhizomes can be flushed with air were reflected in amino acid patterns in basal culm internodes. The fractions of Ala, Ser and gamma-aminobutyric acid of total amino acid content were significantly increased at stands with tall, thick shoots but low densities. The contentsof these amino acids were correlated with parameters of convective ventilation, and may indicate hypoxic conditions in basal and below-ground plant parts of P. australis. In conclusion, biometric parameters of reed stands can be decisive for determining the efficiency of convective ventilation. |
| Title: Copper- and iron-induced injuries in roots and rhizomes of reed (Phragmites australis). |
| Author: Mook-Jaap-H ; Wiegers-Jaap. |
| Source: Limnologica-. Jan., 1999; 29 (1) 60-63. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: About 1 mg/g dw Cu2+ and 8 mg/g dw Fe2+ were found in roots of reed plants when fed with heavy metal concentrations of 100 muM Cu2+ and 10 mM Fe2+ under hypoxia. Roots seemed to act as a kind of filter since the amounts in rhizomes were only 0.06 mg Cu2+/g dw and 2 mg Fe2+/g dw. Increased contents of both ions reduced posthypoxic respiration capacity by 40-50% and also the sum of adenylates (ATP, ADP, AMP) by the same order of magnitude, although energy charge values remained above 0.85 in Cu2+ and 0.79 in Fe2+ treatments. Energy metabolism of rhizomes was not affected. Copper and iron contents of roots as well as of rhizomes were high enough to induce oxidative stress when roots were fed with 40 muM Cu2+ and 1 mM Fe2+, respectively. From our results we conclude that increased, but environmentally attainable, amounts of copper and reduced iron ions disturb root energy metabolism, and therefore root functioning and development. Latent injuries, based on oxidative stress, may be harmful for roots and rhizomes under long term exposure. |
| Title: Seed production of Menyanthes trifoliata inside and outside a Phragmites australis canopy. |
| Author: Haraguchi-Akira. |
| Source: Journal-of-the-Faculty-of-Agriculture-Hokkaido-University. Feb., 1999; 69 (1): 27-30. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Reproduction of Menyanthes trifoliata L. was compared inside and outside a Phragmites australis (Cav.) Trin. ex. Steud. canopy in a floating peat mat in Mizorogaike Pond, Central Japan. Different factors influenced the reproductive organs of M. trifoliata during the seed production process inside and outside the P. australis canopy. M. trifoliata inside the canopy produced a low number of flower buds, but the inflorescences showed a higher survival rate than at the open site, hence inflorescence density per unit area did not differ significantly. However, both the seed setting ratio and the total number of seeds produced were much lower within the Phragmites site. |
| Title: Surface energy fluxes of Phragmites australis in a prairie wetland. |
| Author: Burba-G-G; Verma-S-B ; Kim-J. |
| Source: Agricultural-and-Forest-Meteorology. April 1, 1999; 94 (1): 31-51. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Components of the surface energy balance were measured in three communities (Phragmites australis, Scirpus acutus, and open water) in a wetland located in northcentral Nebraska, USA, during the growing season of 1994. This paper includes results from the area covered by Phragmites australis (reedgrass). The Bowen ratio - energy balance method was used to calculate sensible and latent heat fluxes. During daytime, with a water depth of about 0.5 m, the heat storage term (G) consumed 20-30% of the net radiation (Rn). At night, G was a significant source of energy (on average, about - 40 W m-2). The magnitude of the daily (24 h) averaged G was small. Evapotranspiration (ET) was a major consumer of the incoming solar energy. During early and peak growth, the daily ET ranged between 2.5 and 6.5 mm per day. During senescence, evapotranspiration was between 0.5 and 3.1 mm per day. ET was partitioned into transpiration (Ev) and evaporation (Es) using a dual-source modification of the Penman-Monteith equation. Results indicated that transpiration contributed 40-45% of the total ET in the beginning of the early growth stage. During the second half of the early growth stage and the entire peak growth stage, it contributed 53-62% of ET. The contribution decreased to 50% in the beginning of senescence, and to near zero in late senescence. The daytime variation of Es did not follow Rn, and seemed to be controlled by thermal stability and air dryness. Before senescence, the ratio of the actual to equilibrium evapotranspiration (ET/ETeq) averaged 1.3. It decreased to about 0.5 during senescence. The McNaughton and Spriggs (1989, IAHS Publ. 177, 86-101) model, developed primarily for dryland vegetation, significantly overestimated the ET/ETeq ratio in Phragmites when the canopy stomatal resistance was larger than 150 s m-1. The model prediction improved significantly when the contribution of evaporation was eliminated by substituting the ET/ETeq ratio by Ev/Eveq (transpiration/equilibrium transpiration). |
| Title: Effect of climate on the salt tolerance of two Phragmites australis populations. II. Diurnal CO2 exchange and transpiration. |
| Author: Lissner-Jorgen ; Schierup-Hans-Henrik; Comin-Francisco-A; Astorga-Valeria. |
| Source: Aquatic-Botany. Sept., 1999; 64 (3-4): 335-350. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: This study examined the effects of salinity and climate on instantaneous CO2 exchange rates and daily carbon balance for two populations of Phragmites australis. Plants propagated from seeds collected in Denmark (=Danish population) and Spain (=Spanish population) were grown at salinities of 0, 5 and 10% at outdoor experimental plots situated at a nemoral growth site (Denmark, 56degreeN) and at a mediterranean growth site (Spain, 41degreeN). In situ measurements of shoot CO2 exchange were made under different meteorological conditions. Maximum CO2 uptake rates were 24 and 19 mumol m-2 s-1 in Spain and Denmark, respectively, and were only reached under conditions of full sunlight. On sunny days, CO2 uptake was reduced less by salinity at the Spanish site than at the Danish site. Photosynthetic photon flux densities saturating shoot photosynthesis were much lower in Spain (ca. 600 mumol m-2 s-1) as compared to those in Denmark (ca. 1300 mumol m-2 s-1). This affected the periodof maximum CO2 uptake rates which was 2-3 h longer at the Spanish growth site, despite shorter day length at this site (15 h) than at the Danish site (17 h). Dark respiration rates of shoots were higher at the Spanish growth site (2-8 mumol CO2 m-2 s-1) as compared to the Danish site (less than 2 mumol CO2 m-2 s-1). Salinity was observed to accelerate rates of dark respiration only at the Spanish site. Integrals of shoot CO2 exchange rates over a 24 h period indicated lower total daily carbon gain at the Danish site, which under clear sky conditions was 65-80% of that at the Spanish site. Cloud cover was found to reduce net photosynthetic CO2 uptake considerably and could even cause a net loss of carbon during periods, which in absence of clouds could confer maximum uptake rates. The salt tolerance and productivity of P. australis is therefore strongly related to the ratio of realised to potential sun hours. This ratio may override the importance of other environmental factors such as temperature. This study also evaluated the effects of moderate salinity stress (0-15% salinity) on in situ P. australis transpiration. Daily transpiration rates were 30-75% higher at the Spanish site (0.38-0.56 g H2O cm-2 day-1) as compared to the Danish site (0.22-0.38 g H2O cm-2 day-1). Rates were equally affected by salinity at both the growth sites. Since water loss is an important factor behind P. australis salt tolerance it is speculated that salt tolerance may increase under conditions favouring high transpiration, contrary to most other halophytes. |
| Title: Rhizome age structure of three populations of Phragmites australis (Cav.) Trin. ex Steud.: Biomass and mineral nutrient concentrations. |
| Author: Cizkova-Hana ; Lukavska-Jaroslava. |
| Source: Folia-Geobotanica. 1999; 34 (2): 209-220. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: The rhizome age structure for populations of Phragmites australis (Cav.) Trin. ex Steud. was determined at three sites of the Trebon Biosphere Reserve (Czech Republic). These sites were classified according to plant species composition and phosphorus availability as oligotrophic (Branna), mesotrophic (Rozmberk East) and hypertrophic (Rozmberk West). P. australis stands at these sites were expanding, stabilized and retreating, respectively. Rhizomes were sampled within the terrestrial parts of the reed stands (at a water depth of about 10 cm). The rhizomes were dated according to the position in the branching hierarchy and to supplementary morphological criteria. The analysis of the branching pattern revealed that at the sites studied, the rhizomes typically branch only once a year. The longest life span of rhizomes (six years) was found for the stable reed population at Rozmberk East. The reduced rhizome life span at Rozmberk West (four to five years), accompanied by a reduced branching frequency of horizontal rhizomes, was ascribed to a greater incidence of anaerobic conditions associated with the permanent flooding of the hypertrophic organic soil. The maximum life span of the Branna population (four years) probably corresponds to the total age of the reed population. The concentrations of nitrogen, phosphorus, and potassium in the tissue decreased with rhizome age while those of calcium and magnesium increased. The effect of rhizome age on mineral-nutrient concentrations was more pronounced than the effect of site on these concentrations. The mineral nutrient concentrations were not closely associated with reed performance. |
| Title: The effects of litter on growth and plasticity of Phragmites australis clones originating from infertile, fertile or eutrophicated habitats. |
| Author: Clevering-Olga-A. |
| Source: Aquatic-Botany. May, 1999; 64 (1): 35-50. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: In many European countries a strong decline of Phragmites australis (Cav.) Trin. Ex Steudel (common reed) has been observed. In some instances this decline has been related to the accumulation of litter. A greenhouse experiment was conducted with P. australis cuttings from different stable and die-back populations in the Czech Republic and the Netherlands, which were grown in sand (oxidised substrate) and a mixture of sand and litter (reduced substrate). The stable populations were from fertile and infertile habitats, and the die-back populations from orginally infertile and now eutrophicated habitats. It was hypothesised that (i) clones from stable populations in fertile habitats are better adapted to accumulated litter (reduced substrate) than those in infertile habitats, and (ii) clones from dieback populations in eutrophicated habitats are more similar to those from stable populations in infertile than fertile habitats, and (iii) the allocation and morphological traits inducedin the different environments are adaptive i.e. result in a higher total dry weight (as a measure of fitness) in a particular environment. No significant population X substrate type interaction terms were present, therefore, populations did not differ in their responses to accumulated litter. Population differences in total dry weight, allocation and morphological traits could not be related to adaptations to accumulated litter. Therefore, the different hypotheses were rejected. Generally, clones from infertile habitats were more similar and less plastic than those from the fertile and eutrophicated habitats. Some of these latter clones had a significantly higher total dry weight in sand, but others in sand-litter. Although substrate-type had no overall effect on total dry weight, it affected almost all other plant traits. Clones growing in sand-litter had a higher dry matter allocation to leaves, leaf weight ratio, specific leaf weight ratio, and number of shoots than plants growingin sand, whereas the allocation of dry matter to stems and roots, shoot length and the distance between shoots was lower for clones growing in sand-litter than in sand. Between substrate-types no differences in dry matter of rhizomes were present, however, clones growing in sand-litter produced longer, but thinner rhizomes than those in sand. It was concluded that responses of P. australis to accumulated litter were directed towards a high input of oxygen into a small volume of substrate. It was concluded that a low dry matter allocation to roots, short shoots and a small distance between primary shoots seem to be stress reactions rather than adaptive responses in sand-litter. In contrast, a high number of especially primary shoots seems to be adaptive in this substrate. |
| Title: Study on the salinity-adaptation physiology in different ecotypes of Phragmites australis in the Yellow River Delta of China: Osmotica and their contribution to the osmotic adjustment. |
| Author: Zhao-K-F ; Feng-L-T; Zhang-S-Q. |
| Source: Estuarine-Coastal-and-Shelf-Science. Aug., 1999; 49 (SUPPL. A): 37-42. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: In the Yellow River Delta, there are four ecotypes of Phragmites australis: freshwater swamp reed; salty-water swamp reed; lower salt-meadow reed and higher salt-meadow reed. The growth status, composition and dominance of the reed community were observed. The organic and inorganic osmotica, osmotic potential and osmotic adjustment ability of reeds were determined. The abundance, coverage, plant height, leaf water content and osmotic potential all decreased with increasing salinity of habitats. K+ and sugars are the main osmotica in lower salinity, while Na+ is the main osmoticum in higher salinity. Na+ contents and the osmotic adjustment abilities of roots are higher than those in leaves. Na/K ratios of reeds varied with salinity levels of habitats, being about 1 in higher salinity. Moreover, the contributions of osmotica to the osmotic adjustment change with salinity, the higher the salinity level, the greater the contribution of inorganic osmotica, but the smaller the contribution of organic osmotica. |
| Title: The macrofungi and decay of roofs thatched with water reed, Phragmites australis. |
| Author: Anthony,-P.A. |
| Source: Mycological-Research [Mycol.-Res.] 1999 vol. 103, no. 10, pp. 1346-1352. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: This study examined the occurrence or macrofungi and the decay of roofs thatched with water reed, Phragmites australis. Sampling from 20 north- and 20 south-facing roof sides showed that several ascomycetes usually associated with reed in situ are common on thatch. The only basidiomycetes recorded were Mycena species. There was no significant difference in the representation of macrofungi on north- and south-facing roof sides, but Mycena spp. only produced basidiomes on surfaces facing north, suggesting that the dry environment of the south side prevents fruiting. Eleven species were recorded in total, and the average of 2 times 4 species per roof did not increase with the age of thatch or degree of decay. The same species were generally present on young and old thatch, and no successional stages of fungal communities could be distinguished with increasing roof age. Deterioration of thatch occurs at the exposed surface of the roof and progresses inwards. Within the layer of reeds outer, middle, and inner zones develop representing different stages in the decay. The zones move inwards as thatch deteriorates. A comparison of the rate of decay among roofs with pitch 30 degree , 45 degree and 60 degree showed that the innermost zone appeared ca 20 cm from the exposed reed butts in both of the steeper roofs, whereas it was no longer present in the roof with low pitch. This suggests that the depth of the zones depends upon the roof slope, and the outer and middle zones move inwards at a higher rate in roofs with a low pitch, resulting in an increased rate of deterioration. Phragmites thatch appears to harbour its own characteristic macrofungal community, with certain Mycena species likely to represent the principal decomposers. A common feature of fungi occurring on thatch is that they must endure unfavourable conditions. |
| Title: A comparative study of surface energy fluxes of three communities (Phragmites australis, Scirpus acutus, and open water) in a prairie wetland ecosystem. |
| Author: Burba-George-G ; Verma-Shashi-B ; Kim-Joon. |
| Source: Wetlands-. June, 1999; 19 (2): 451-457. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Components of the surface energy balance were measured using the Bowen ratio-energy balance method in three different communities (Phragmites australis, Scirpus acutus, and open water) in a wetland located in north-central Nebraska during the growing season of 1994. During daytime, the heat storage term (S) was a considerably larger sink of energy in open water as compared to the vegetated communities (Phragmites and Scirpus). During nighttime, S was a significant source of energy in all three communities. As compared to the evapotranspiration (ET) from Phragmites and Scirpus, the evaporation (E) from open water (averaged over the measurement period) was about 25% smaller during daytime and three times larger during the night. The diurnal pattern of ET in Phragmites and Scirpus generally followed that of Rn. The diurnal pattern of the open water E, however, did not follow Rn; rather, it seemed to depend on thermal stability conditions and air dryness. For the overall measurement period, the daily integrated (24-hour) evaporation from the open water area was 8% more than the evapotranspiration from the Phragmites-dominated part of the wetland and 17% more than the evapotranspiration from the Scirpus-dominated part of the wetland. |
| Title: The effect of light and number of diurnal temperature fluctuations on germination of Phragmites australis. |
| Author: Ekstam-B ; Johannesson-R; Milberg-P. |
| Source: Seed-Science-Research. June, 1999; 9 (2): 165-170. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: Seed germination of the wetland emergent perennial Phragmites australis is stimulated by diurnally fluctuating temperatures. A germination experiment in darkness and light at different temperature regimes showed that P. australis germinated as well in darkness as in light over most of the temperature regimes tested. The germination requirements could partly explain why this species, despite a large annual production of small seeds, does not accumulate a persistent soil seed bank. A second experiment examined the effect of one to four diurnal temperature cycles with amplitude of fluctuations ranging from 0 to 30degreeC; diurnal mean temperature of 15degreeC. Germination in the absence of fluctuations was low, and logistic model estimates showed a positive effect of number of temperature cycles which was strongly influenced by amplitude size. For seeds that have fallen on moist ground during the winter, these laboratory results predict that a few large diurnal temperature fluctuations couldbe sufficient for onset of germination in the subsequently warmer spring period. Seeds that are located under water, however, are predicted to remain ungerminated until the water level falls. Hence, we suggest that the requirement for fluctuating temperature, in addition to being a sensor for 'exposed' seed sites, is also effectively acting as a germination timing mechanism. |
| Title: Habitat factors related to the invasion of reeds (Phragmites australis) into wet meadows of the Swiss Midlands. |
| Author: Brulisauer-Alfred ; Klotzli-Frank. |
| Source: Zeitschrift-fuer-Oekologie-und-Naturschutz. Dec., 1998; 7 (3) 125-136. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Habitat factors related to the invasion of reeds into Molinia coerulea-dominated wet meadows and small-sedge communities were investigated by transect analysis. The abundance of Phragmites was found to be strongly related to increased levels of soil nitrogen and phosphates. A competitive advantage of Phragmites over other species of wet meadows at increased nutrient levels may result from an improved capacity to cope with unbalanced nutrient situations, such as high levels of nitrogen but low levels of potassium. |
| Title: Implications of missing efflux sites on convective ventilation and amino acid metabolism in Phragmites australis. |
| Author: Rolletschek-H ; Bumiller-A; Henze-R; Kohn-J-G. |
| Source: New-Phytologist. Oct., 1998; 140 (2) 211-217. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Three stands of Phragmites australis (Cav.) Trin. ex Steudel were investigated regarding the relationship between the number of efflux culms and convective ventilation efficiency affecting the hypoxic status of roots and rhizomes. The lack of old (efflux) culms after mowing the preceding winter caused a significantly higher counterpressure within the rhizome, thereby diminishing air flushing rate, i.e. oxygen supply, of rhizomes. The levels of alanine and gamma-aminobutyric acid in basal culm internodes increased significantly. Both amino acids indicate the hypoxic status of the root and rhizome metabolism of P. australis. Amino acid patterns of the basal culm internodes are discussed with respect to the maintenance of aerobic root metabolism and nutrient availability. |
| Title: Comparison of biomass and metal uptake between two populations of Phragmites Australis grown in flooded and dry conditions. |
| Author: Ye-Z-H; Wong-M-H; Baker-A-J-M ; Willis-A-J. |
| Source: Annals-of-Botany-London. July, 1998; 82 (1) 83-87. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: The biomass and metal concentrations of two populations of Phragmites australis were studied by growth in a glasshouse in three ameliorated substrata (Mai Po (MP) sediment, fly ash (FA) and lead/zinc mine tailings (TL)) under flooded and dry conditions for 90 d. Plants were raised from seeds from 'clean' (Mai Po, Hong Kong) and metal-contaminated (Plombieres, Belgium) sites. Seedling growth was best in fly ash, root dry weights being higher in flooded than dry conditions, and growth poorest in tailings, in which shoot and root dry weights were higher under dry conditions for both populations. However, in the MP substratum conditions did not significantly affect shoot and root dry weights of either population. In the fly ash aid tailings, more metals were generally taken up in both roots and shoots in flooded than dry conditions, but there was little difference in the MP substratum. Metal uptake was mostly similar in both populations in seedlings grown in the same substratum, there being no clear evidence of ecotypic differentiation. |
| Title: An investigation into the effects of nitrogen on growth and morphology of stable and die-back populations of Phragmites australis. |
| Author: Clevering-Olga-A. |
| Source: Aquatic-Botany. Jan., 1998; 60 (1) 11-25. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: In many European countries a strong decline of Phragmites australis (common reed) populations has been observed during the past two decades. This has become known as die-back or reed regression. A greenhouse growth experiment was performed with P. australis cuttings from stable and die-back populations from The Czech Republic and The Netherlands. The stable populations were from fertile and infertile environments, and the die-back populations were originally from infertile but now eutrophicated habitats. It was hypothesised that (i) stable P. australis populations from fertile and infertile habitats would show inherent differences in biomass (allocation) and N-content in response to nitrogen loading, and (ii) die-back populations would be more similar to stable populations from infertile as opposed to fertile habitats in terms of biomass (allocation) and N-content. The stable Czech populations showed an increase in dry weight with increasing fertility of the habitat. This was not related, however, to leaf area ratio (LAR), specific leaf area (SLA) or nitrogen use efficiency (NUE). The dry weight of the stable Dutch populations did not vary with fertility, although the population from the infertile habitat showed a higher allocation of dry watter and nitrogen to the below-ground parts as compared to the fertile habitat population. Total dry weight of the die-back Czech population did not differ from that seen for stable populations from the infertile habitats, and no differences were found between the Dutch populations. Die-back populations did not show a higher resemblance with stable populations from infertile as opposed to fertile habitats with respect to plant traits involved in the capture of light and/or nitrogen. Most plant traits were affected by nitrogen, irrespective of habitat fertility, and populations did differ in morphology and dry matter allocation. However, since performance of populations could not he related to the fertility of the habitat, both hypotheses were rejected. The importance of other selectional processes is discussed. |
| Title: Morphological and histochemical analysis of galls of Lipara lucens (Diptera, Chloropidae) on Phragmites australis (Poaceae). |
| Author: Vandevyvere-Inez ; De-Bruyn-Luc. |
| Source: Canadian-Journal-of-Botany. Aug., 1998; 76 (8) 1374-1384. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Lipara lucens Meigen (Diptera, Chloropidae) is a monophagous herbivore of the common reed. Phragmites australis Cav. (Trin.) ex Steud. (Poaceae), on which it induces typical cigar-shaped galls. In this paper, the anatomy and histochemistry of galls, cultivated in a greenhouse and collected in the field. were examined. Gall growth takes place while the larva feeds outside the actual developing gall. During gall growth, internode elongation is reduced. Internally, the pith parenchyma, destined to become the nutritive tissue, proliferates instead of degenerating as is seen in uninfested stems. The tissue cylinder around the gall chamber widens up to three times its normal size, while the pith parenchyma doubles its width. The central pith of nutritive cells becomes surrounded by an inner layer of longitudinal and an outer layer of radial parenchymatous cells. Vascular strands, likely connected to the vascular tissue of the host plant, run through this special band of parenchyma cells. The bundles are oriented perpendicular to the stem axis, surrounding the larval chamber. When the gall is completed, the larva gnaws through the growing point and enters the gall chamber, where it consumes the nutritive tissue. A sclerenchymatization process starts now resulting in an extremely hardened gall. Histochemical staining reveals the presence of proteins, DNA, RNA, and a gradient of lipid globules in the nutritive tissue. No starch was detected. |
| Title: Abundance of common reed (Phragmites australis), site conditions and conservation value of fen meadows in Switzerland. |
| Author: Guesewell-Sabine; Kloetzli-Frank. |
| Source: Acta-Botanica-Neerlandica. March, 1998; 47 (1) 113-129. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: The abundance of Phragmites australis (Trin.) has increased in many fen meadows of the Swiss Plateau. The vegetation of 241 4-m2 plots was surveyed to determine how the abundance of Phragmites australis was related to site conditions and to the botanical conservation value. The aboveground biomass of P. australis (ABP) ranged from 0 g to 1270 g dry weight m-2. ABP was positively correlated to the nitrogen indicator value of the vegetation, but uncorrelated to the soil moisture indicator value. The abundance of 55 of 85 plant species was significantly related to ABP. High ABP was, on an average, associated with low conservation value in terms of species richness, number of rare or endangered species, and proportion of typical mire species. Strong differences were, however, found between plots with tall-herb vegetation (alliance Filipendulion) and plots dominated by heathgrass or small sedges (alliances Molinion and Caricion davallianae). The conservation value of Filipendulion plots was low and decreased significantly with increasing ABP. The conservation value of Molinion and Caricion plots was generally high and not related to ABP. Nevertheless, the current spread of P. australis might reduce the conservation value of Molinion and Caricion meadows in three ways: (1) a direct impact of shading is likely to become apparent only after several years; (2) if P. australis spreads into a site together with tall herbs, the loss of conservation value will be greater than if only tall herbs invade; and (3) if the presence of P. australis increases nutrient availability, it may indirectly cause the spread of tall herbs and the resulting loss of conservation value. Thus, spread of P. australis, spread of tall herbs and increased productivity are strongly related to each other and must be considered together when changes in the vegetation of fen meadows are evaluated. |
| Title: Seasonal variation in methane oxidation by the rhizosphere of Phragmites australis and Scirpus lacustris. |
| Author: van-Der-Nat-Frans-Jaco-W-A; Middelburg-Jack. |
| Source: Aquatic-Botany. June, 1998; 61 (2) 95-110. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Methane oxidation in the rhizosphere of two common wetland plants, reed (Phragmites australis (Cav.) Trin. Ex Steud.) and bulrush (Scirpus lacustris L.), was quantified using the methylfluoride (CH3F) inhibition and anoxic/oxic flux chamber techniques. The similarity of rhizospheric CH4 oxidation rates determined with the two techniques and the absence of an adverse effect of CH3F on plant metabolism indicated that the CH3F inhibition flux chamber technique was a useful tool for measuring rhizospheric CH4 oxidation in freshwater wetlands. A significant seasonal pattern for both plant species as well as a significant difference between the plant species were observed. Light or dark conditions had no significant effect on rhizospheric CH4 oxidation. When averaged over the growing season, CH4 oxidation in the rhizosphere of bulrush and reed reduced the potential CH4 flux by 34.7%+-20.3 and 16.1%+-7.86, respectively. Highest CH4 oxidation rates were noted early in the plant growth cycle with more than 55% of the generated methane being oxidized in the bulrush system. Methane oxidation rates were lowest after plants matured. The difference in rhizospheric CH4 oxidation capacity between reed and bulrush and the seasonal variation for reed were confirmed by a series of slurry incubations. Slurry incubations also showed a significant decrease of potential CH4 oxidation as a function of depth in sediment. |
| Title: Evidence for the vertical distribution of saprophytic fungi on senescent Phragmites australis Culms at Mai Po Marshes, Hong Kong. |
| Author: Poon-M-O-K; Hyde-K-D. |
| Source: Botanica-Marina. May, 1998; 41 (3) 285-292. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: The vertical distribution of fungi on decaying stems and leaf sheaths of Phragmites australis has been investigated in gei wais (tidal shrimp farms) in the intertidal region at Mai Po Marshes, Hong Kong. Fungal communities permanently submerged in the gei wai, are different to those in the intertidal region. Both exhibit a vertical distribution, the latter with a narrower distribution range. The operation of the gei wai has altered the natural vertical distribution of the mycota therein, so that most intertidal fungi occur at the interface between water and air. |
| Title: Above and belowground production of Phragmites australis in the Po Delta, Italy. |
| Author: Scarton-Francesco ; Day-John-W; Rismondo-Andrea. |
| Source: Bollettino-del-Museo-Civico-di-Storia-Naturale-di-Venezia. July 15, 1998 (1999); 49 (0): 213-222. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: From March through October 1995 above- and belowground production for Phragmites australis were studied in a tidally affected reedbed close to the mouth of the Po delle Tolle distributary in the Po Delta. This site is subject to periodic influx of sea water as well as prolonged freshwater conditions during high river flow. Growth took place mostly between May and August. Aboveground production was 876 g d.w./m2, with a peak live biomass of 780 g/m2; belowground production was 2263 g/m2 with a peak live biomass of 4087 g/m2. The net efficiency, with regard to Phragmites australisR, was 1.1%. These production values are comparable with others observed at Mediterranean coastal sites, but regular submersion by salt water probably leads to lower aboveground biomass and higher belowground biomass at the Po Delta site. |
| Title: Effects of salinity and sulfide on the distribution of Phragmites australis and Spartina alterniflora in a tidal saltmarsh. |
| Author: Chambers-Randolph-M ; Mozdzer-Thomas-J; Ambrose-Joelle-C. |
| Source: Aquatic-Botany. Nov., 1998; 62 (3) 161-169. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: In laboratory studies, the short-term response of Phragmites australis and Spartina alterniflora to root immersion in solutions of different salinity and sulfide concentration was measured as the rate of ammonium depletion (a proxy for root uptake) from an initial concentration of 20 muM. From 0 to 20 ppt in the absence of sulfide, ammonium uptake as a function of dry root weight decreased for both Phragmites (from 29.7 +- 3.5 s.e. to 8.2 +- 1.5 mumol N g-1 h-1) and Spartina (from 25.5 +- 3.5 to 9.0 +- 1.5 mumol N g-1 h-1). With an average sulfide concentration of 582 muM at 20 ppt, the rate of ammonium uptake for Spartina (10.9 +- 2.2 mumol N g-1 h-1) was not significantly different from the rate in the absence of sulfide. In contrast, the rate of ammonium uptake was significantly lower for Phragmites when the average sulfide concentration was increased from 0 to 375 muM (1.7 +- 1.6 mumol N g-1 h-1). In a tidal saltmarsh, the average porewater sulfide concentration in Phragmites australis stands (124 +- 206 muM) was almost an order of magnitude lower than that measured in stands of Spartina alterniflora (989 +- 166 muM). These field and laboratory results support the notion that increased sulfide in the rhizosphere reduces the ability of Phragmites to take up nutrients relative to species such as Spartina that are better-adapted to sulfidic soil conditions, thus restricting the distribution of Phragmites in tidal saltmarshes. |
| Title: Effects of litter accumulation and water table on morphology and productivity of Phragmites australis. |
| Author: Clevering,-O.A. |
| Source: Wetlands-Ecology-and-Management [Wetlands-Ecol.-Manage.] 1998 vol. 5, no. 4, pp. 275-287. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Phragmites australis (Common reed) occurs in the interface between water and land. The water depth gradient from deep water to dry land is inversely related to litter accumulation. Eutrophication can result in an excessive production of litter, which may have a large impact on the occurrence of P. australis in this gradient. In an outdoor pot experiment, it was investigated how water tables in combination with substrates containing variable amounts of litter affect morphology and productivity of P. australis. Vegetatively propagated P. australis was grown in pots filled with river sand, litter, and different mixtures of sand and litter (25, 50 and 75% by volume). Four water table treatments were applied; drained (-12 cm), waterlogged (0 cm), flooded (+12 cm), and weekly fluctuating drained and flooded conditions (-12/+12 cm of water relative to substrate level). When drained, no differences between substrate treatments were present. Waterlogging, flooding and fluctuating water table treatments caused growth reduction in substrate containing litter. The plants formed short shoots and thin rhizomes. With increasing water table, allocation of dry matter to stems increased at the expense of leaves and rhizomes. At intermediate levels of litter in the substrate, allocation to leaves was lowest. In both instances a lower leaf weight ratio (LWR) was (partly) compensated for by a higher specific leaf area (SLA), resulting in less pronounced differences in leaf area ratio (LAR). Aquatic roots developed when plants were waterlogged or flooded, and increased when litter was present in the substrate. Aquatic roots were formed in the top soil layer when waterlogged. The percentage of aquatic roots increased with increasing amount of litter in the substrate when plants were flooded. It was concluded that the morphological responses of P. australis to litter strongly constrain its ability to maintain itself in deep water when the substrate contains litter. This might be one of the explanations for the disappearance of P. australis along the waterward side of littoral zones. |
| Title: Rhizome respiration of Phragmites australis: Effect of rhizome age, temperature, and nutrient status of the habitat. |
| Author: Cizkova-Hana ; Bauer-Vaclav. |
| Source: Aquatic-Botany. Aug., 1998; 61 (4) 239-253. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Respiration rates of rhizomes were studied in field populations of Phragmites australis (Cav.) Trin. ex Steud. at three sites of the Trebon Biosphere Reserve (Czech Republic), which were classified (according to plant species composition and phosphorus availability) as oligotrophic, mesotrophic and hypertrophic, respectively. P. australis stands at these sites were expanding, stabilized and retreating respectively. Rhizomes were sampled within the terrestrial parts of the reed stands (at a water depth of about 10 cm). The seasonal course of respiration rate was measured as CO2 release for main age categories of horizontal rhizomes and was supplemented with more detailed studies of age categories of both horizontal and vertical rhizomes. On all sites, the respiration rates remained fairly stable through the year. The mean seasonal respiration rates of 1-year-old horizontal rhizomes were 3.94 +- 0.39, 3.10 +- 0.39 and 2.99 +- 0.39 mumol CO2 g-1 dry wt h-1 (mean +-95% confidence for mean) for Branna, Rozmberk East and Rozmberk West, respectively. The respiration values were inversely related to rhizome age, reaching only 2.66+-0.40, 2.28+-0.40, and 2.72 +- 0.40 in 3-year-old rhizomes at the respective sites. A reverse pattern was found in May when the respiration rates of 3-year-old and 4-year-old rhizomes surpassed those of 1-year-old ones by 0.95, 1.18 and 3.89 mumol CO2 g-1 dry wt h-1 at the three sites, respectively, in 1994, and by 2.08 and 2.51 mumol CO2 g-1 dry wt h-1 at Rozmberk East and Rozmberk West, respectively, in 1997. No substantial differences between sites or age categories were found in the response to temperature at three of four dates investigated; the mean values of the apparent activation energy Ea (including data of all three age categories) were 44.1, 49.0, and 51.2 kJ mol-1 for Branna, Rozmberk East, and Rozmberk West, respectively. The corresponding geometrical means of Q10 values were 1.94, 2.10 and 2.18, respectively. Ea was negatively correlated with age in May yielding an R2 value of 0.55. Branna had the highest respiration rates of all three sites. In 1994 it reached a mean seasonal respiration rate of 3.26 +- 0.23, compared to 2.79 +- 0.23 and 2.74 +- 0.23 mumol CO2 g-1 dry wt h-1 (mean +-95% confidence for mean) for Rozmberk East and Rozmberk West, respectively. Detailed studies performed in 1996 revealed that Rozmberk East had lower respiration rates than Rozmberk West. This difference was largely due to the respiration of the young rhizome parts; thus, subapical segments of newly formed rhizomes reached 13.99 +- 2.16 and 19.28 +- 2.15 mumol CO2 g-1 dry wt h-1, and 1-year-old rhizomes reached 5.25 +- 0.53 and 6.40 +- 0.53 mumol CO2 g-1 dry wt h-1 for Rozmberk East and Rozmberk West, respectively. The differences between sites were relatively small compared to the differences between age categories. |
| Title: Remarkable resistence of Phragmites australis (Cav.) Trin. growing on soils intoxicated by magnesium immissions. |
| Author: Hronec,-O.; Hajduk,-J. |
| Source: Ekologia-Bratisl.-Ecology-Bratisl. 1998 vol. 17, no. 2, pp. 117-124. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Magnesium immissions consist of 65-80 % of MgO. They increase soil alcali reaction up to pH 9.2 and unfavourably turn soil structure from the crumb structure into the prismatic one. On the affected sites, about 10 plant species predominate among which Ph. australis begun to spread, as a new ecotype, during last 20 years. Ph. australis forms mostly elliptic-circular patches of 20-33 m in diameter on the place of former pastures and forests where it did not occur before construction of the magnesium plant. In average, 21 stems (1 fertile) per m super(2) grew up in one year in the close vicinity of the immission source, while 44 (6 fertile) in the distance of 1800 m. Number of internodia did not exceed 22. After Agrostis stolonifera, Phragmites australis shows the highest vitality in such habitats. It grows even on alkaline soils with pH 9.1 and level of Mg and Ca of 13.528 mg.kg super(-1) and 1163 mg.kg super(-1) respectively. Ph. australis is a perspective dominant, resistant and technically usable species exhibiting an antierosive effect and allowing an alternative solution of soil reclamation and vegetation regeneration in surroundings of magnesium plants. |
| Title: Remarkable resistance of Phragmites australis (Cav.) Trin. growing on soils intoxicated by magnesium immissions. |
| Author: Hronec-Ondrej ; Hajduk-Juraj. |
| Source: Ekologia-Bratislava. 1998; 17 (2) 117-124. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Magnesium immissions consist of 65-80% of MgO. They increase soil alcali reaction up to pH 9.2 and unfavourably turn soil structure from the crumb structure into the prismatic one. On the affected sites, about 10 plant species predominate among which Ph. australis begun to spread, as a new ecotype, during last 20 years. Ph. australis forms mostly elliptic-circular patches of 20-33 m in diameter on the place of former pastures and forests where it did not occur before construction of the magnesium plant. In average, 21 stems (1 fertile) per m2 grew up in one year in the close vicinity of the immission source, while 44 (6 fertile) in the distance of 1800 m. Number of internodia did not exceed 22. After Agrostis stolonifera, Phragmites australis shows the highest vitality in such habitats. It grows even on alkaline soils with pH 9.1 and level of Mg and Ca of 13.528 mg.kg-1 and 1163 mg.kg-1 respectively. Ph. australis is a perspective dominant, resistant and technically usable species exhibiting an antierosive effect and allowing an alternative solution of soil reclamation and vegetation regeneration in surroundings of magnesium plants. |
| Title: Cyanidin 3-O-(6"-succinyl-beta-glucopyranoside) and other anthocyanins from Phragmites australis. |
| Author: Fossen-Torgils; Andersen-Oyvind-M. |
| Source: Phytochemistry-Oxford. Oct., 1998; 49 (4) 1065-1068. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Three anthocyanins were isolated from the flowering tops of Phragmites australis. Their structures were elucidated by means of homo- and heteronuclear two-dimensional NMR techniques and mass spectrometry to be cyanidin 3-O-(6"-O-succinyl-beta-glucopyranoside) (2%), cyanidin 3-O-(6"-O-malonyl-beta-glucopyranoside) (64%) and cyanidin 3-O-beta-glucopyranoside (34%). The former pigment, which is a new anthocyanin, represents the first identification of an anthocyanin acylated with succinic acid found outside the dicotyledon genus Centaurea (Compositae). |
| Title: Does mowing in summer reduce the abundance of common reed (Phragmites Australis)? |
| Author: Gusewell-Sabine. |
| Source: Bulletin-of-the-Geobotanical-Institute-ETH. 1998; 64 (0) 23-35. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Common reed (Phragmites australis Trin.) has recently spread in fen meadows of the Swiss Plateau, where it might reduce species richness and displace typical fen species. 2 Mowing experiments were carried out in two fens near Zurich to investigate whether mowing in June (in addition to the usual September cutting) is an effective measure to reduce the abundance of Phragmites. Changes in the number and size of Phragmites shoots were monitored during three years. The aboveground biomass and nutrient concentrations of Phragmites and of all other vascular plant species ("other species") were determined in the third year of the experiment. 3 The additional June cutting had no significant effect on shoot number and size, and, therefore, on the aboveground biomass of Phragmites during this period. The biomass of Phragmites did not differ between treatments, but the biomass of the other species was lower in plots with additional June cutting. Due to this additional cutting, 90% more N and 181% more P were, on an average, removed with Phragmites, but only 30% more N and 64% more P with the other species. Thus, the nutrient economy of Phragmites was stronger affected than the nutrient economy of the rest of the species. 4 The availability of nutrients and interspecific competition are probably decisive for the long-term treatment effects. Further monitoring is needed to evaluate whether mowing in June and September will eventually reduce the abundance of Phragmites by depleting its belowground reserves. However, the results of this study indicate that other means (e.g. grazing) are necessary for a short-term control. |
| Title: Does invasion of oligohaline tidal marshes by reed grass, Phragmites australis (Cav.) Trin. ex Steud., affect the availability of prey resources for the mummichog, Fundulus heteroclitus L.? |
| Author: Fell-Paul-E ; Weissbach-Sonja-P; Jones-Douglas-A; Fallon-Mark-A; Zeppieri-Julie-A; Faison-Edward-K; Lennon-Kristen-A; Newberry-Kate-J; Reddington-Linda-K. |
| Source: Journal-of-Experimental-Marine-Biology-and-Ecology. April 1, 1998; 222 (1-2) 59-77. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Reed grass (Phragmites australis (Cav.) Trin. ex Steud.) has invaded large areas of tidal marsh along the lower Connecticut River and often occurs as a monoculture. Tidal marsh invertebrates (snails, amphipods and isopods) were common to abundant in reed grass-dominated regions, as well as in areas covered by typical tidal marsh vegetation at four sampling stations set up along the salinity gradient. This finding suggests that reed grass marshes provide suitable physical habitat and usable food resources for these semiaquatic detritus/algae feeders. Mummichogs (Fundulus heteroclitus L.) were caught on the high marsh during daylight high tides using Breder traps and an analysis of their gut contents was made. When daylight tides were high enough to cover the marsh surface, mummichogs moved up onto the marsh and fed extensively on marsh invertebrates, both in reed grass marshes and reed grass-free marshes. Such foraging appears to represent a direct trophic link between the marshes and adjacent estuarine waters. Even when tides were not high enough to flood the marsh surface, mummichogs moved into the tidal creeks that course through reed grass marshes and largely reed grass-free marshes and foraged there. With respect to macroinvertebrate populations and mummichog foraging, the reed grass marshes appear to be functioning in essentially the same ways as nearby marshes not invaded by this plant, at least in the short term. |
| Title: Seasonal changes in dissolved amino acids and sugars in basal culm internodes as physiological indicators of the C/N-balance of Phragmites australis at littoral sites of different trophic status. |
| Author: Kohl-Johannes-Guenter ; Woitke-Peter; Kuehl-Harald; Dewender-Marion; Koenig-Gabriele. |
| Source: Aquatic-Botany. March, 1998; 60 (3) 221-240. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: The nitrogen content of different internodes and the dissolved amino acids and sugars of the basal culm internodes of Phragmites australis (Cav.) Trin. ex Steud. were studied monthly in 1994 to estimate the carbon/nitrogen balance at eight sites and lakes. These stands had large differences in standing crop, with less than 400 g shoot dry weight m-2 in a mesotrophic lake and up to 1500 g dry weight m-2 in hypertrophic lakes. No significant differences were found between sites in the nitrate and ammonium concentration of the interstitial water because of very high variability in space and time. The relative nitrogen content (% of dry weight) of different leaves and culm internodes showed significant differences but only between the most different sites. The amount and composition of free amino acids and sugars of the basal culm internodes showed a clear association with the maximum standing crop of the sites. During the later shoot growth phase (July to September), plants of the high productivity sites exhibited a high content of dissolved amino acids in the basal culm internodes with asparagine as the main transport and storage compound, but a very low sugar content with sucrose as the main transport component in summer. At low productivity sites of mesotrophic to moderate eutrophic lakes, this relationship was inverse. The mean of the proportions of total sugars to total amino acids and asparagine to sucrose, respectively, were significantly correlated with the maximum standing crop of the eight sites. Alanine and serine were present in high concentration in early spring before outgrowth of the tiller without pressure induced ventilation of the subtending vertical rhizome parts. The results are discussed with respect to the indicatory value of the amino acid and sugar content of the basal shoot internodes to the productivity of the different stands and their limitation by the nitrogen availability of the plants. |
| Title: Phragmitensis marina gen. et sp. nov., an intertidal saprotroph from Phragmites australis in Hong Kong. |
| Author: Wong-M-K-M; Poon-M-O-K; Hyde-K-D. |
| Source: Botanica-Marina. July, 1998; 41 (4) 379-382. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Phragmitensis marina gen. et sp. nov. is described based on a collection from culms of Phragmites australis made in the intertidal region of Mai Po Marshes and Ting Kok, Hong Kong. The genus is characterized by ascomata forming in linear groups under a common pseudostroma, clavate asci lacking an apical structure and unicellular cymbiform hyaline ascospores which are surrounded by a mucilaginous sheath. Phragmitensis marina is illustrated with interference contrast and scanning electron micrographs. |
| Title: Diel methane emission patterns from Scirpus lacustris and Phragmites australis. |
| Author: Van-Der-Nat-Frans-Jaco-W-A; Middelburg-Jack-J ; Van-Meteren-Danielle; Wielemakers-Annette. |
| Source: Biogeochemistry-Dordrecht. April, 1998; 41 (1) 1-22. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: In mature Phragmites australis and Scirpus lacustris vegetated sediment methane was emitted almost exclusively by plant-mediated transport, whereas in unvegetated, but otherwise identical sediment, methane was emitted almost exclusively by ebullition. Diel variations in methane emission, with highest emission rates at daytime and emission peaks following sunrise, were demonstrated for Phragmites and Scirpus. The diel difference and magnitude of the emission peaks were much smaller for Scirpus than for Phragmites. In contrast to Phragmites, methane concentrations within Scirpus stems did not change significantly over the diel period. These patterns are consistent with a two-way transport mechanism for Phragmites (convective at daytime and diffusive at night-time) and an all day diffusive mechanism for Scirpus. The patterns could not be accounted for by diel variation in air and sediment temperature, plant transpiration, or photosynthetically coupled methane production. Comparison of the experimentally derived ratio of methane emission in helium and nitrogen under light and dark conditions with the theoretical derived ratio (calculated according to the kinetic theory of gases) confirmed the exploitation of the different transport mechanism for Phragmites and Scirpus. Methane emission from Phragmites correlated significantly with incident light, which probably drove the pressure differential associated with thermally induced convection. Decrease of the radial resistance of Scirpus stems for methane transport under light compared to dark conditions, in combination with morphological characteristics of the plant species, suggested that stomatal aperture, regulated by light, controls methane emission from Scirpus. Diel variation in bubble emission from the non-vegetated sediment coincided with sediment temperature changes. The results have important implications for sampling and scaling strategies for estimating methane emission from wetlands. |
| Title: Chromosome numbers of Phragmites australis (Arundineae: Gramineae) in New Zealand. |
| Author: Connor-H-E ; Dawson-M-I; Keating-R-D; Gill-L-S. |
| Source: New-Zealand-Journal-of-Botany. Sept., 1998; 36 (3) 465-469. |
| Source Type: Journal |
| Publication Date: 1998 |
| Abstract: Somatic chromosome numbers for New Zealand provenances of Phragmites australis are reported. A wide range of cytological variation was encountered-one plant was tetraploid (2n = 4x2 = 48), two were octoploid (2n = 8x2 = 96), and two were mixoploid (2n = 48, 53, 54; and 2n = 96, c. 264). One Australian provenance was octoploid. Possible regions of origin for the New Zealand populations are suggested, and multiple introductions postulated, although it is conceivable that some octoploids could be indigenous in a cytodeme shared with Australia. |
| Title: Effects of salinity on the growth of Phragmites australis. |
| Author: Lissner-Jorgen; Schierup-Hans-Henrik. |
| Source: Aquatic-Botany. 1997; 55 (4) 247-260. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: The field salinity tolerance of Phragmites australis was evaluated by investigating 27 natural reed habitats along the eastern and western coasts of Jutland, Denmark. Die-back took place in the lower fringe of stands, before the onset of flowering, at sites where soil water salinities were higher than 15 permill within the rooting depth. In greenhouse experiments, juvenile plants produced from seeds and rhizome-grown plants, grown over a range of salinity levels, displayed different levels of salt tolerance. Both types of plants showed low mortality at salinity levels of 15 permill and lower. A total of 75% of the rhizome-grown plants survived 22.5 permill salinity in the rooting medium, whereas only 12% of the juvenile plants survived this salinity level. All plants grown at salinity levels of 35 permill and 50 permill died. Relative growth rates of juvenile plants were negatively correlated with salinity levels. Relative growth rates of rhizome-grown plants on a wet weight basis showed an optimum at 5 permill salinity. However, rates based on leaf number and shoot height were unaffected by salinities from 0-5 permill , but decreased at higher salinities. Phragmites australis adapted to saline conditions by adjusting the level of osmotically active solutes in its leaves. In the salinity range allowing survival (0-22.5 permill ) osmolality in leaves of rhizome-grown plants was approximately 200 mmol kg-1 higher than medium osmolality. In leaves of juvenile plants, osmotic pressure and chlorinity increased exponentially at salinity levels above 10 permill in the rooting medium, indicating a lower capability of osmoregulation. However, water stress could also be responsible for the lower resistance to salinity of these juvenile plants, as was suggested by a wilted appearance of leaves exposed to high salinities. Leaf longevity was not affected by different salinity treatments. Phragmites australis did not use leaf abscission to excrete toxic salts during the growth season. |
| Title: The fate of 15N-nitrate in healthy and declining Phragmites australis stands. |
| Author: Nijburg-J-W ; Laanbroek-H-J. |
| Source: Microbial-Ecology. Nov.-Dec., 1997; 34 (3) 254-262. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: The dissimilatory nitrate-reducing processes, denitrification, and dissimilatory nitrate-reduction to ammonium were studied in freshwater lake sediments within healthy and degrading Phragmites australis (reed) stands. The samples from the healthy vegetation site contained roots and rhizomes. Cores were supplied with 1.9-5.2 mug 15N-NO3- g-1 dry sediment in the laboratory and subsequently incubated for 8 h at 20degree C, in the dark. The 15N compounds were determined before (natural percentage of 15N) and after 1 and 8 h of incubation. The uptake of 15N by the roots and rhizomes in the healthy vegetation was 61%. Nitrogen losses, interpreted as denitrification, accounted for 25 and 84% of the added 15N-NO3- in sediment from the healthy and degrading vegetation sites, respectively. The percentages of nitrate reduced to ammonium were 4 and 9% in sediment from the healthy vegetation and degrading vegetation sites, respectively. The percentage of 15N-total N in the sediment of the healthy vegetation site was 10%, whereas for the degrading vegetation site this percentage was 7%. The percentage of nitrate reduced to ammonium could be potentially underestimated by the percentage of 15N measured in the sediment. In this case, in healthy and degenerating P. australis stands, the percentage of produced ammonium accounted for 14-16%. The nitrate reduction rates were calculated based on an incubation period of one hour. The denitrification rate in sediment from the degrading vegetation site was higher than from the healthy vegetation site. The rate of dissimilatory nitrate reduction to ammonium was almost tenfold higher in sediment from the degrading vegetation site compared to sediment from the healthy vegetation site. The significantly lower percentages of dissimilatory nitrate reduction to ammonium and denitrification in the healthy stand compared to the degrading stand was probably due to the presence of roots and rhizomes. In the sediments of healthy and degrading P. australis stands, denitrification was the main nitrate-reducing process. |
| Title: Die-back of Phragmites australis in European wetlands: An overview of the European Research Programme on Reed Die-back and Progression (1993-1994). |
| Author: van-Der-Putten-Wim. |
| Source: Aquatic-Botany. Dec., 1997; 59 (3-4) 263-275. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Reed (Phragmites australis (Cav.) Trin. ex Steudel) is one of the dominant plant species in European land-water ecotones. During the past decades reed belts have died back, especially in central and eastern Europe. The aim of the European Research Programme on Reed Die-back and Progression (EUREED), was to examine how increasing eutrophication, changed water table management, temperature, reduced genetic variation and their interactions may contribute to reed die-back. Eutrophication appeared to be a key factor, but the effects on P. australis were indirect, via the accumulation and decay of litter and allogenous organic matter, rather than acting directly via disturbed carbohydrate cycling or reduced porosity of the aerenchymous plant tissue. The formation of toxic byproducts of decomposing litter in anoxic environment, such as acetic acid, may reduce reed vigour. Sulphide may act as a principal toxin especially at brackish sites, such as Lake Fert, Hungary. There were large differences in genetic variability. However, populations from eutrophic sites did not grow faster and were not more plastic than populations from oligotrophic sites. Variation within populations could be large as compared to variation between populations when exposed to nitrogen, liquid manure and litter. DNA-fingerprinting showed differences between land and water reeds. This may be due to a differential selective force during establishment, e.g., when the water table recovers after a drawdown. Selection by water table during establishment could affect the susceptibility of clones in the mature stage for indirect effects of eutrophication. It was concluded that in stagnant water bodies the present water table management enforces the effects of eutrophication on the reed die-back. In addition, local disturbances, such as the mechanical mowing of reeds may enhance reed die-back. |
| Title: Die-back of Phragmites australis: Influence on the distribution and rate of sediment methanogenesis. |
| Author: Sorell-Brian-K ; Brix-Hans; Schierup-Hans-Henrik; Lorenzen-Bent. |
| Source: Biogeochemistry-Dordrecht. 1997; 36 (2) 173-188. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Methanogenesis was measured during the summer of 1994, in sediment cores and bulk samples from a Phragmites australis wetland in northern Jutland, Denmark. We compared sediment from healthy reed and dying-back reed, and an open lagoon resulting from die-back. Cores revealed variability with depth and between sites, with the highest rates coinciding with layers of organic gyttja, and negligible methane production from the underlying sand base. Methanogenesis rates in the lagoon and die back sites were higher (up to 100-150 nmol h-1 g-1 dry wt. sediment) than in the healthy reed (50-80 nmol h-1 g-1), with the highest rates being recorded from May to July. At these times, methanogenesis was markedly temperature-limited; samples incubated at 30 degree C a non-limiting temperature, gave rates as high as 200-400 nmol h-1 g-1 for the lagoon and die-back areas and 150 nmol h-1 g-1 for the healthy area. Addition of 8 mM acetate and H-2/CO-2 headspace suggested that both acetate-fermenting and CO-2-reducing bacteria were present. Acetate additions suggested some co-limitation by substrate availability, with acetate limitation occurring in the healthy site during July and in the die-back site during August. Lower rates during August, especially in the healthy area, were associated with low water levels which resulted in more oxidized sediments. The data reveal highly variable methanogenesis in the sediment which, when considered with sediment depths, indicates that sites of Phragmites die-back have significantly greater rates of anaerobic mineralization than surrounding healthy wetland, and may be intense sources of methane. |
| Title: Strategies of nitrogen cycling of Phragmites australis at two sites differing in nutrient availability. |
| Author: Kuehl,-H.; Woitke,-P.; Kohl,-J.-G. |
| Source: INT.-REV.-GESAMT.-HYDROBIOL. 1997 vol. 82, no. 1, pp. 57-66. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Below-ground biomass and nitrogen content were determined at two genetically homogeneous Phragmites stands differing in morphology, in productivity, and in nutrient supply. Comparable ratios between above-ground standing crop and rhizome biomass were found at both sites, whereas the root biomass/above standing crop ratio was significantly higher at the nutrient poor site. Investigations on the dynamics of nitrogen content revealed distinct differences in nitrogen translocation to the rhizomes between the investigated clones indicating two ecophysiological strategies in storage behaviour. These two strategies could be attached to the "assimilation type" and to the "translocation type", respectively. A modified definition of both types is presented. |
| Title: Investigation and long-term monitoring of Phragmites australis within Virginia's constructed wetland sites. |
| Author: Havens-Kirk-J ; Priesti-Walter-I-Ii; Berquist-Harry. |
| Source: Environmental-Management. 1997; 21 (4) 599-605. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: The use of constructed wetlands to replace natural wetlands is becoming pandemic. An investigation using global positioning system technology to map the vegetated communities of 15 of the largest constructed wetlands in Virginia reveals that 80% are colonized by the invasive species, Phragmites australis Trin., and/or aggressive species, Typha spp. Tidally influenced wetlands that have subtidal perimeter ditches have significantly less (P lt 0.05) P. australis in the wetland interior than those without perimeter ditches. Fractured regression analyses show that 6 years after construction, P. australis invasion can be extensive. Linear regression analysis suggests that, if conditions remain favorable for P. australis colonization, constructed wetlands could be overrun in 40 years. |
| Title: Zinc, lead and cadmium tolerance, uptake and accumulation by the common reed, Phragmites australis (Cav.) Trin. ex Steudel. |
| Author: Ye-Z-H; Baker-A-J-M ; Wong-M-H; Willis-A-J. |
| Source: Annals-of-Botany-London. 1997; 80 (3) 363-370. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Zinc (Zn), lead (Pb) and cadmium (Cd) tolerance in populations of seedlings of Phragmites australis raised from seeds collected from a mine site (Plombieres, Belgium) contaminated with Zn, Pb and Cd and three 'clean' sites (Felixstowe, UK; Wisbech, UK; and Mai Po, Hong Kong) were studied under glasshouse conditions. Small differences were found between the metal-contaminated population and the three 'clean' populations when seedlings were grown in 1.0 mu-g ml-1 Zn and 10.0 mu-g ml-1 Pb treatment solutions. In general, however, different populations of seedlings showed similar growth responses, metal uptake and indices of Zn, Pb and Cd tolerance when cultured in the same metal-contaminated media for 89 d or in the same metal treatment solutions (ZnSO-4: 1.0 and 4.0 mu-g ml-1 Zn; Pb(NO-3)-2: 10-0 and 25.0 mu-g ml-1 Pb; CdSO-4: 0.5 and 1.0 mu-g ml-1 Cd) for 3 weeks. There was insufficient evidence to support the hypothesis that the metal-contaminated population has evolved to a Zn-, Pb- or Cd-tolerant ecotype but the results indicated some differentiation between the populations with that from Hong Kong being the least productive under the experimental conditions used. The implications of the findings on selection of provenances for use in constructed wetlands for wastewater treatment are discussed. |
| Title: Some aspects of the importance of genetic diversity in Phragmites australis (Cav.) Trin. ex Steudel for the development of reed stands. |
| Author: Koppitz-H ; Kuehl-H; Hesse-K; Kohl-J-G. |
| Source: Botanica-Acta. 1997; 110 (3) 217-223. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Various sites of Phragmites australis in Germany (Uckermark and Mark Brandenburg) and sites in Hungary and Denmark were investigated by PCR fingerprinting in order to determine their genetic diversity. Genetic similarities were calculated and, based on this, a cluster analysis was performed. The genetic similarity of reed clones around one lake ranged from between 70 to 100%, that of clones from different lakes was clearly lower. The further apart the clones were situated from each other, the less similar they were. At a wetland site near the shore a sudden colonisation by several new Phragmites clones was observed. This site was located in front of a well established genetically almost homogenous stand within the eulittoral. All the results are discussed in connection with a proposed model of establishment and development of water reed stands: colonization, selection of best adapted clones by competition and the stability of stands. |
| Title: Rhizome architecture in Phragmites australis in relation to water depth: Implications for within-plant oxygen transport distances. |
| Author: Weisner-Stefan-E-B ; Strand-John-A. |
| Source: Folia-Geobotanica-et-Phytotaxonomica. 1996; 31 (1) 91-97. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Phragmites australis (CAV.) TRIN. ex STEUD. is a perennial plant, largely relying on its rhizomes for resource storage, spreading and anchorage in the substrate. Vertical distribution and length of horizontal rhizomes of Phragmites australis were investigated at the reed bed edge in a lake in southern Sweden. In deep water, horizontal rhizomes were relatively short and superficially situated in the substrate. It is hypothesised that this is an adaptation to water depth by keeping O-2-transport distances through shoots and rhizomes as short as possible. In shallow water, P. australis rhizomes generally penetrated deeply into the substrate, probably improving anchorage and nutrient uptake possibilities. Further, horizontal rhizomes were longer in shallow water, which may increase the rate of vegetative spread. Because of these changes in rhizome architecture, "critical within-plant oxygen transport distances" did not change with water depth. This indicates that P. australis maximises the extension of its rhizomes in relation to spatial differences in water depth. This may limit the ability of P. australis to tolerate sudden temporal increases in water depth or eutrophication. |
| Title: Nitrogen and carbohydrate pools of two rhizome types of Phragmites australis (Cav.) Trin. ex Steudel. |
| Author: Woitke,-P.; Kiehl,-A.; Kuehl,-H.; Kohl,-J.-G. |
| Source: INT.-REV.-GESAMT.-HYDROBIOL. 1997 vol. 82, no. 2, pp. 161-168. |
| Source Type: Journal |
| Publication Date: 1997 |
| Abstract: Carbohydrate and total nitrogen contents as well as free amino acid (FAA) concentrations were determined in distinct types of rhizomes of two genetically homogeneous stands of reed (Phragmites australis (Cav.) Trin. ex Steudel) differing in morphology, productivity and nutrient supply in order to evaluate the storage capacity of vertical rhizomes and expansion rhizomes. The expansion rhizomes possess significantly higher amounts of FAA and of total nitrogen but similar carbohydrate concentrations in comparison to the vertical rhizomes. However, no significant differences were found for total nitrogen, FAA and total carbohydrates between both investigated stands indicating a comparable storage capacity of rhizomes independent of nutrient availability. Only the composition of the FAA pool varied in the alanine/asparagine ratio probably influenced by the oxygen supply of the rhizome/root system. |
| Title: Temporal variations in the nitrogen content of Phragmites australis (Cav.) Trin. ex. Steud. from a shallow fertile lake. |
| Author: Boar-Rosalind-R. |
| Source: Aquatic-Botany. 1996; 55 (3) 171-181. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Despite large differences in the amounts of nitrogen that accumulated in shoots, the amounts of nitrogen stored over a 4 year period in the rhizomes of Phragmites australis from a fertile English lake did not change. Rhizomes sampled in November contained a 4-year mean (+- SD) of 22 +- 3 g m-2 of nitrogen in an annual mean dry weight of 2360 +- 290 g m-2. Shoots contained between 8 +- 1 g m-2 and 20 +- 10 g m-2 nitrogen in the midsummer of the different years and from 0.2 +- 0.4 g m-2 to 18 +- 7 m-2 in November. In the early winters, the mass of nitrogen still contained in standing dead stems was equivalent to between 1% and 49% of the combined shoot and rhizome-nitrogen. Thus, the sometimes large amounts of nitrogen that were potentially available for downward translocation to rhizomes were not reclaimed. This behaviour is typical of relatively open nutrient cycles where, over the longer-term, net storage of incoming nutrients does not occur. |
| Title: Nesting of Remiz pendulinus on Phragmites australis. |
| Author: Giacola-Vittoria. |
| Source: Rivista-Italiana-di-Ornitologia. 1996; 66 (1) 73-74. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: NA |
| Title: Does ammonium affect accumulation of starch in rhizomes of Phragmites australis (Cav.) Trin. ex Steud.? |
| Author: Kubin-Petr; Melzer-Arnulf. |
| Source: Folia-Geobotanica-et-Phytotaxonomica. 1996; 31 (1) 99-109. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Reed rhizomes from four habitats differing in soil nitrogen availability were collected and analysed for carbohydrate content during one year. Rhizomes collected from sediments where nitrate was the prevailing form of available nitrogen accumulated predominantly starch. On the other hand, rhizomes buried in sediments rich in ammonium contained predominantly sucrose. These observations together with the fact that ammonium stimulates the activity of enzymes involved in degradation of starch suggest that ammonium affects starch storage by inducing conversion of starch into sucrose. During spring when sprouting takes place, the rates of sucrose or starch mobilization differed remarkably, the sucrose in rhizomes buried in ammonium-rich sediments being depleted much faster than the starch in rhizomes at ammonium-poor habitats. The consequent reduction of total carbohydrate content in rhizomes at ammonium-rich habitats places the plants in a vulnerable situation. Eutrophication and reed decline are postulated to be events causally related via toxicity of ammonium, of which considerable amounts are microbiologically released from decaying organic matter in reed beds under excessive nutrient supply. |
| Title: Effect of oxygen availability and salinity on early life history stages of salt marsh plants. I. Different germination strategies of Spartina alterniflora and Phragmites australis (Poaceae). |
| Author: Wijte-Antonia-H-B-M; Gallagher-John-L. |
| Source: American-Journal-of-Botany. 1996; 83 (10) 1337-1342. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Gradients in oxygen availability and salinity are among the most important environmental parameters influencing zonation in salt marsh communities. The combined effects of oxygen and salinity on the germination of two salt marsh grasses, Spartina alterniflora and Phragmites australis, were studied in growth chamber experiments. Germination of both species was initiated by emergence of the shoot and completed by root emergence. Percentage S. alterniflora germination was reduced at high salinity (40 g NaCl/L) and in decreased oxygen (5 and 2.5%). In 0% oxygen shoots emerged, but roots did not. P. australis germination was reduced at a lower salinity (25 g NaCl/L) than S. alterniflora, and inhibited at 40 g NaCl/L and in anoxia. However, a combination of hypoxia (10 and 5% O-2) and moderate salinity (5 and 10 g NaCl/L) increased P. australis germination. When bare areas in the salt marsh are colonized, the different germination responses of these two species to combinations of oxygen and salt concentrations are important in establishing their initial zonation. In high salinity wetlands S. alterniflora populates the lower marsh and P. australis occupies the high marsh at the upland boundary. |
| Title: Air and soil temperatures during burnings in a Phragmites australis community, Hakone Sengokuhara, central Japan. |
| Author: Tsuda,-S. |
| Source: ECOL.-REV. 1996 vol. 23, no. 3, pp. 209-212. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Wetlands such as marsh, bog, fen, and so on are mostly composed of many herbaceous plants like grasslands. The ground condition of wetland is different from that of xeric grassland, because the ground is always saturated with water. There is a possibility that plant regeneration after burning in wetland will differ from the regeneration of xeric grassland. This paper presents data on air and soil temperatures during burning in a fen community of Phragmites australis. |
| Title: Ecology and biomass of Phragmites australis (Cav.) Trin. Ex. Steud. in the north-eastern region of the Nile Delta, Egypt. |
| Author: Serag-Mamdouh-S. |
| Source: Ecoscience-. 1996; 3 (4) 473-482. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Phragmites australis (Cav.) Trin Ex. Steud., the common reed is one of the most abundant species in the north-eastern region of the Nile Delta (Egypt). The phytosociological pattern of Phragmites australis was studied in relation to the most prevailing edaphic factors. The present results indicate that the maximum abundance of Phragmites was recorded in rich organic matter and alkaline habitats. In addition, field studies indicate that Phragmites is often associated with halophytes such as Arthrocnemum macrostachyum (Meikle) Moq., Halocnemum strobilaceum (Pallas) M. Beib and Aster squamatus (Spr.) Hieron ex Sod. Moreover, the reed tolerates soil conductivity up to 12 mS/cm and pH 7.0 to 9.3. The maximum above-ground biomass of the reed in 1992 occurred in September and was 5500 g/m-2 (fresh) and 4400 g/m-2 (dry). On the other hand, the maximum below-ground biomass occurred in October and was 2500 g/m-2 (fresh) and 1100 g/m-2 (dry). The succulence ratio varied seasonally, with the highest values for above-ground parts in April and March for below-ground parts. |
| Title: Carbohydrate levels in rhizomes of Phragmites australis at an oligotrophic and a eutrophic site: A preliminary study. |
| Author: Cizkova-Hana ; Lukavska-Jaroslava ; Priban-Karel ; Kopecky-Jiri; Brabcova-Hana. |
| Source: Folia-Geobotanica-et-Phytotaxonomica. 1996; 31 (1) 111-118. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Seasonal dynamics of total nonstructural carbohydrates (TNC) and of carbohydrate species (starch, sucrose, glucose, fructose) were followed in rhizomes of Phragmites australis at two sites of the Trebon Biosphere Reserve (Czech Republic): Branna sand pit and Rozmberk fishpond-western shore, which were classified (according to plant species composition and phosphorus availability) as oligotrophic and hyper-eutrophic, respectively. Phragmites stands at these sites were expanding and retreating, respectively. Rhizomes were sampled within terrestrial parts of the reed stands (at a water depth of about 10 cm). The levels of total non-structural carbohydrates were determined mainly by levels of starch and sucrose, while glucose and fructose were present at comparatively low levels. The most conspicuous differences between the sites were associated with autumnal and March levels of carbohydrates. In March, i.e. at the beginning of vegetative development, TNC and starch levels were lower at the hypereutrophic, as compared with the oligotrophic, site. Starch and TNC levels fell from August to September at the hyper-eutrophic, but not at the oligotrophic, site. At the low water depth investigated, the differences between stands in carbohydrate levels do not seem to be large enough to account solely for their different vigour. It is suggested that the effect of water depth needs to be evaluated in more detail. |
| Title: Variation in seed production and germinability in common reed (Phragmites australis) in Britain and France with respect to climate. |
| Author: McKee-Juno; Richards-A-J. |
| Source: New-Phytologist. 1996; 133 (2) 233-243. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Northern populations of Phragmites australis (Cav.) Trin. ex Steud. (common reed) often flower so late that the ability to produce viable seeds before winter dieback can be limited. If climate changes as predicted, the reed may become able to set seed further north in its range. This would have implications for the ability of reed to colonize new sites as well as for the distribution of animals which eat reed seeds in winter. A survey of 34 British populations in 1993 and 1994 showed that seed production is highly variable between sites, ranging from 0 to 100%. Southern and western populations tended to show the highest seed sets, although some southern populations were infertile and some northern sites set seed. Average seed weight tended to be higher in sites which showed good seed set. Seeds from sites with high average seed weight tended to germinate more readily. The seed-setting capability of populations was successfully associated with climatic conditions at the time of flowering. However, seed weight was not found to relate to climate, but depended on seed production and overall plant height. Logistic regression modelling indicated that the best seed sets should occur in P. australis when: (i) August rainfall is low; (ii) the combined rainfalls of September and October are high; and (iii) the combined temperatures of these months are high. The model accounts for approximately one third of the variation in observed seed sets between sites, indicating that other, unmeasured, factors might also play a part in determining seed set in P. australis. At three northern populations which were studied in more detail, a number of genotypes coexisted, and legitimate pollen germination and pollen-tube growth was observed in each case. As no seed set occurred in two of these, self-incompatibility cannot explain poor seed setting. |
| Title: Comparisons of nutrient recovery and specific leaf area variation between Carex lasiocarpa var. occultans and Carex thunbergii var. appendiculata with reference to nutrient conditions and shading by Phragmites australis. |
| Author: Onimaru-Kazuyuki ; Yabe-Kazuo. |
| Source: Ecological-Research. 1996; 11 (2) 139-147. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The distribution of two sedge species was studied in two mires which differ in abiotic environments and in distribution of Phragmites australis. Carex lasiocarpa var. occultans dominated in nutrient-poor valley mire, and Carex thunbergii var. appendiculata dominated in nutrient-rich flood plain subject to water fluctuations. Phragmites australis grew well in nutrient-rich conditions. The distribution of C. lariocarpa showed a strong negative correlation with P. australis coverage, whereas C thunbergii coverage was not affected by P. australis. The leaf area per dry leaf mass (specific leaf area: SLA) of C thunbergii increased with shading by P. australis, but that of C. lasiocarpa was stable. The SLA flexibility of C thunbergii to light interception, might enable this species to invade P. australis patches in nutrient-rich environments. The residual nutrient ratio of nitrogen and phosphorus (the ratio of the residual nutrient content at the end of the growing season to peak nutrient content) in the vegetative ramet of C thunbergii was 1.7 times higher than that of C lasiocarpa. This low residual ratio may indicate effective nutrient recovery to storage organs. The effective nutrient recovery in C lasiocarpa might enable this species to grow even in nutrient-poor environments. However, it may be difficult for C. lasiocarpa to expand its habitat to nutrient-rich areas where P. australis dominates as it is not shade tolerant. |
| Title: Response of Phragmites australis, Glyceria maxima, and Typha latifolia to additions of piggery sewage in a flooded sand culture. |
| Author: Cizkova-Koncalova,-H.; Kvet,-J.; Lukavska,-J. |
| Source: WETLANDS-ECOL.-MANAGE. 1996 vol. 4, no. 1, pp. 43-50. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: One-year-old clones of Phragmites australis, Glyceria maxima, and Typha latifolia were subjected to different doses of piggery sewage added in flooded sand cultures for one growing season. Phragmites responded to increasing sewage doses by an increase in the shoot biomass and a decrease in root porosity and carbohydrate levels in rhizomes; Glyceria responded by a decrease in the biomass and depth penetration of the root system, and carbohydrate levels in rhizomes. In contrast, Typha increased in both root porosity and carbohydrate levels in rhizomes. These findings are discussed in relationship to plant performance in sewage-polluted wetlands. |
| Title: Pathways of aeration and the mechanisms and beneficial effects of humidity-and Venturi-induced convections in Phragmites australis (Cav.) Trin. ex Steud. |
| Author: Armstrong-J ; Armstrong-W; Beckett-P-M; Halder-J-E; Lythe-S; Holt-R; Sinclair-A. |
| Source: Aquatic-Botany. 1996; 54 (2-3) 177-197. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The pathways of diffusive, humidity- and Venturi-induced convective ventilations in Phragmites australis (Cav.) Trin. ex Steud., and the mechanisms of the convections are described. Experimental evidence, indicating those factors, e.g. low relative humidity (RH), light, large leaf-sheath area, which increase humidity-induced convection, and those which increase Venturi convections, e.g. high wind speed, are reviewed. The superior aerating effects of convective as opposed to diffusive ventilation within the plant and their influence on the rhizosphere are demonstrated experimentally and by mathematical modelling. |
| Title: Seasonal variation of nutrients and heavy metals in Phragmites australis of Lake Trichonis, Greece. |
| Author: Nikolaidis-Nikolaos-P ; Koussouris-Theodoros; Murray-Thomas-E; Bertahas-Ilias; Diapoulis-Aristidis; Gritzalis-Konstantinos. |
| Source: Lake-and-Reservoir-Management. 1996; 12 (3) 364-370. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Farming practices and other anthropogenic influences have affected the water quality and shifted trophic state of Lake Trichonis, western Greece, from oligotrophic to oligo-mesotrophic. This change has been accompanied by an expansion of dense reed beds of Phragmites australis in places where limited growth existed in the past. This study measured the seasonal changes in nutrients and heavy metals in the reed beds of Lake Trichonis, and assessed the applicability of reed harvesting on maintaining or improving the water quality of the lake. The results have illustrated three types of accumulation dynamics of nutrients and heavy metals in the reeds of Lake Trichonis. The first type shows maximum accumulation occurring early in the growing season and gradually throughout the year. P, K, Cl and NO, follow this type of accumulation. The second pattern followed by fluoride, showed constant accumulation throughout the year. The third accumulation pattern, followed by NA, Zn, Cd, Co, Mn, Fe, Mg, Ca, Cu, Al, Ni, Cr, and So-4, showed increases in accumulation throughout the growing season, reaching a maximum in August and September and then declined steadily. the reeds beds are a significant sink for nutrients in the early growing season and a potentially significant source of nutrients later in season. the results indicate that removal of the reeds in the early spring would remove a large reservoir of potentially mineralizable P from the lake. To properly control the flow of nutrients and heavy metals in a lake through reed harvesting, the dynamic cycling of P and the seasonal changes in accumulation should be considered. |
| Title: Temporal variations in the nitrogen content of Phragmites australis (Cav.) Trin. ex Steud. from a shallow fertile lake. |
| Author: Boar,-R.R. |
| Source: AQUAT.-BOT. 1996 vol. 55, no. 3, pp. 171-181. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Despite large differences in the amounts of nitrogen that accumulated in shoots, the amounts of nitrogen stored over a 4 year period in the rhizomes of Phragmites australis from a fertile English lake did not change. Rhizomes sampled in November contained a 4-year mean ( plus or minus SD) of 22 plus or minus 3 g m super(-2) of nitrogen in an annual mean dry weight of 2360 plus or minus 290 g m super(-2) Shoots contained between 8 plus or minus 1 g m super(-2) and 20 plus or minus 10 g m super(-2) nitrogen in the midsummer of the different years and from 0.2 plus or minus 0.4 g m super(-2) to 18 plus or minus 7 g m super(-2) in November. In the early winters, the mass of nitrogen still contained in standing dead stems was equivalent to between 1% and 49% of the combined shoot and rhizome-nitrogen. Thus, the sometimes large amounts of nitrogen that were potentially available for downward translocation to rhizomes were not reclaimed. This behaviour is typical of relatively open nutrient cycles where, over the longer-term, net storage of incoming nutrients does not occur. |
| Title: Sulphide utilization and injuries in hypoxic roots and rhizomes of common reed (Phragmites australis). |
| Author: Fuertig-Konrad; Ruegsegger-Adrian; Brunold-Christian; Braendle-Roland. |
| Source: Folia-Geobotanica-et-Phytotaxonomica. 1996; 31 (1) 143-151. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The presented investigations have been carried out in order to estimate toxic sulphide levels and to examine detoxification capabilities in roots and rhizomes of the common reed (Phragmites australis). Underground organs of common reed are sensitive towards sulphide above 1 mM applied exogenously under hypoxia. However, certain tolerance may be achieved by sulphide detoxification. Accumulated sulphide is partially used for the synthesis of non-toxic thiols, mainly glutathione. But the detoxification capacity of the underground organs is limited. Maximum concentrations of thiols are about 60 nmol/g-1 fw in roots and 300 nmol/g-1 fw in rhizomes. Energy metabolism is considerably affected by low sulphide concentrations of 1 mM for 4 days, and immediately disturbed by increased concentrations up to 6 mM sulphide. Adenylate energy charge, total adenylates, posthypoxic respiration, and fermentation capacity decrease significantly. Roots are more sensitive than rhizomes. |
| Title: Effect of oxygen availability and salinity on early life history stages of salt marsh plants. II. Early seedling development advantage of Spartina alterniflora over Phragmites australis (Poaceae). |
| Author: Wijte-Antonia-H-B-M; Gallagher-John-L. |
| Source: American-Journal-of-Botany. 1996; 83 (10) 1343-1350. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: In salt marsh soils, germination and the first phases of seedling development often occur under dark, hypoxic or anoxic, and saline conditions. Spartina alterniflora and Phragmites australis seedling development were examined under covaried oxygen and salinity concentrations in growth chamber experiments. First, the effects of oxygen and salinity on seedling development were tested in the dark, using a 5 times 5 factorial design. Oxygen did not affect P. australis plumule growth at oxygen concentrations from 21 down to 2.5%. Plumules were longer at ltoreq 10 than at gtoreq 25 g NaCl/L. Root growth was maximum in 21% oxygen, at ltoreq 10 g NaCl/L and reduced at all salinities in oxygen concentrations ltoreq 10%. No plumule or root growth occurred under anoxia. Salinity did not affect S. alterniflora mesocotyl emergence, which was fastest in anoxia and hypoxia. Mesocotyls did not emerge from the spikelet in 21% oxygen. In contrast, plumule growth was fastest in 21% oxygen, but was inhibited in anoxia. Under low oxygen and high salinity both plumule and root elongation were reduced. Coleoptile and mesocotyl elongation were greatest in 2.5 and 5% oxygen, and shortest in anoxia. The percentage of mesocotyls elongating was also highest in 2.5% oxygen. Rapid S. alterniflora coleoptile and mesocotyl elongation in anoxia enables its seedlings to escape the impact of the stressful environment where its seeds can germinate, but the seedlings could not survive otherwise. In separate experiments, S. alterniflora seeds were germinated and the seedlings grown in the dark for 10 d, then exposed to light for 4 d. Prior to illumination the seedlings did not develop beyond the stage of a small plumule enclosed in the coleoptile. Within 48 h of illumination in the presence of CO-2, roots emerged and the plumule elongated inside the coleoptile at salinities up to 40 g NaCl/L, while the external environment remained anoxic. Without CO-2, plumule growth and root development did not occur. This suggested oxygen was produced inside the coleoptile by the photosynthesizing plumule, and triggered root development. The ability of S. alterniflora seedlings to continue development under external anoxia and high salinity gives that species a competitive advantage over P. australis in high salinity and/or poorly drained marshes. |
| Title: Evaluation of the ventilation resistance to convective gas-flow in the rhizomes of natural reed beds of Phragmites australis (Cav.) Trin. ex Steud. |
| Author: Kohl-J-G ; Henze-R; Kuehl-H. |
| Source: Aquatic-Botany. 1996; 54 (2-3) 199-210. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The ventilation resistance of the internal gas-space system of common reed rhizomes (Phragmites australis (Cav.) Trin. ex Steud.) to convective gas through-flow was studied at reed stands of different lakes with respect to reed die-back. Some parameters for evaluating the contribution of the culms in ventilating the rhizomes are calculated. This involves the culm's own pressure development (P-c), the counter-pressure within the rhizomes measured at the bottom of the culm (stubble; P-s), and the resistance of the connected rhizome against gas-flow. The advantage of the relation between counter-pressure of rhizomes to the potential pressure differential of the culms (P-s/P-c) and the ventilation resistance parameter (VRP) is that they are not dependent on the actual pressurization due to changing weather conditions. A comparison of different sites is possible even when measured at different times. Most of the reed stands so far investigated show low resistances to convective gas-flow during summer but an increase in resistance was measured during the later vegetation season. Low numbers of old culms functioning as efflux culms can at least partly be compensated by the functional change of living shoots to efflux culms. The gas composition of these green shoots and the dead efflux culms is lower in oxygen and higher in carbon dioxide than influx culms, and additionally methane is present. Very high resistances against gas through-flow could only be detected at sites where the formerly homogeneous distribution of the shoots was changed to a cluster-like distribution with only few or no old culms. |
| Title: Gas fluxes achieved by in situ convective flow in Phragmites australis. |
| Author: Brix-Hans ; Sorrell-Brian-K; Schierup-Hans-Henrik. |
| Source: Aquatic-Botany. 1996; 54 (2-3) 151-163. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The Common Reed (Phragmites australis Cav. Trin. ex Steud.) possesses an outstanding capacity to vent its underground tissues by pressurized through-flow. Phragmites-dominated wetlands therefore potentially provide a significant source of trace gas emissions to the atmosphere. In this paper we present results of in situ studies on gas exchange through Phragmites, and evaluate various methodologies used for measuring gas transport and the fluxes they record. Gas exchange rates were related to atmospheric humidity, temperature and light. Green shoots were influx culms and dead culms and broken or damaged green shoots were efflux culms. Gas exchange through the plants fluctuated diurnally, with highest rates in the early afternoon (up to 11 l m-2 h-1) and lowest rates during the night. The net flux of O-2 to the below-ground tissues and sediment was up to 5.7 l m-2 day-1, and the net emissions of CO-2 and CH-4 up to 5.1 and 0.27 l m-2 day-1 respectively. Net gas exchange rates varied with season and sediment characteristics, being highest during hot and dry summer days, and on organic sediments with a high oxygen demand and high rates of microbial decomposition. Hence, the convective throughflow mechanism in Phragmites not only accelerates gas exchange between the sediment and the atmosphere, but the oxygen delivered through the plant may also affect the microbial processes in the sediment. Therefore, the role of the plants for rhizosphere oxidation and conveyers of gases should be further assessed in future studies. A comparison of current methods for measuring flow suggested that they need refining if they are to quantify gas exchange through Phragmites wetlands on a large scale or over longer time periods. |
| Title: Effects of waves on helophyte stands: Mechanical characteristics of stems of Phragmites australis and Scirpus lacustris. |
| Author: Coops-Hugo ; Van-Der-Velde-Gerard. |
| Source: Aquatic-Botany. 1996; 53 (3-4) 175-185. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The effects of wave attack on stands of the two species Scirpus lacustris L. and Phragmites australis (Cav.) Trin. ex Steudel were studied in a wave tank, and related to bending and breaking characteristics of the stems. Stands of the two species, growing at a water depth of 0.5 m, were exposed to uniform waves with a height of 0.23 m high and a wave period of 1.9 s. Mean stem height and density were reduced strongly in the S. lacustris stands after wave attack. The effects of wave attack on mean stem height and density of P. australis stands were much less pronounced. In both species, critical breaking force and flexural stiffness of stems increased with individual stem height. Bending stiffness was much lower in S. lacustris stems (mean E = 0.25 GPa) than in P. australis stems (mean E = 4.93 GPa). Seasonal variation in stiffness was observed in P. australis stems but not in S. lacustris; for P. australis, E was lower in February (dead standing stalks) and June (young shoots), than in August. Stands of P. australis withstand exposure to waves better than S. lacustris stands as the result of a higher bending stiffness of the stems and a lower susceptibility to breaking under mechanical stress. Therefore, S. lacustris can grow in waterside helophyte fringes when wave exposure is moderate or absent, but cannot survive at highly wave-exposed shores. |
| Title: Senescence, and phytotoxin, insect, fungal and mechanical damage: Factors reducing convective gas-flows in Phragmites australis. |
| Author: Armstrong-J ; Armstrong-W; Armstrong-I-B; Pittaway-G-R. |
| Source: Aquatic-Botany. 1996; 54 (2-3) 211-226. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Premature senescence, insect bore holes and callus development in the gas-transport pathways were each shown to impair convective (pressurised) gas-flows in Phragmites australis (Cav.) Trin. ex Steudel. Premature senescence resulting from aphid and fungal attack, and possibly from the uptake of soil-borne phytotoxins, was found on average to have reduced the gas-flow potential of living culms by at least 70%. This was attributed chiefly to a reduction in humidity-induced convection resulting from a loss of healthy leaf-sheath area. Insect bore holes, found in living culms, reduced potential humidity-induced convective flows by varying amounts, by causing the culms to be leaky. It was shown that the degree of leakiness of culms should be dependent upon the position of the bore holes along the culm. Irrespective of their position and the wind speed, bore holes in old dead culms reduced Venturi-induced convection to almost zero. However, such holes could also increase convective flows by reducing resistance to venting from the underground parts, basal holes conferring lower resistance than more apical ones. In addition, it was concluded that callus development within gas pathways of the plant is stimulated by insect damage, by mechanical damage/flooding and by uptake of phytotoxins such as acetic acid and sulphide, and that extensive callus production might completely impede all pressurised gas flows. It is suggested that each of the above factors has the potential to contribute to Phragmites die-back by adversely affecting rhizome, root and rhizosphere aeration. |
| Title: Seasonal dynamics of aufwuchs Naididae (Oligochaeta) on Phragmites australis in a eutrophic lake. |
| Author: Loehlein-Boris. |
| Source: Hydrobiologia-. 1996; 334 (1-3) 115-123. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: The Oligochaeta and Aphanoneura in the aufwuchs on Phragmites australis in a eutrophic hardwater lake were studied at two sites over a period of one year, in order to elucidate the structure and dynamics of this assemblage. The naidids Chaetogaster diastrophus, Nais spp., and Stylaria lacustris dominated the assemblage at any season. At both sites these taxa showed the same distinct pattern of successive population maxima in spring and summer: Chaetogaster diastrophus reached its peak density first, followed by Nais species, and eventually by Stylaria lacustris. Differences in temporal dynamics between sites were small apart from a second Stylaria maximum which was only observed at one site. Total naidid densities reached peak values of 3.8 individuals per cm-2 reed stem surface area. With mean individual biomass of 2.2 mu-g dry mass for Chaetogaster diastrophus, 13.3 mu-g for Nais, and 86 mu-g for Stylaria lacustris, respectively, maximum total naidid biomass on reed stems was 44 mu-g dry mass per cm-2. The biomass peak occurred later than that of total naidid density because in summer larger naidids dominated the assemblage. The observed succession appears to be consistent with seasonal changes in periphytic algal communities on the reed stems. |
| Title: Effects of an organic sediment on performance of young Phragmites australis clones at different water depth treatments. |
| Author: Weisner-Stefan-E-B. |
| Source: Hydrobiologia-. 1996; 330 (3) 189-194. |
| Source Type: Journal |
| Publication Date: 1996 |
| Abstract: Performance of young Phragmites australis plants was examined after 7 weeks on an artificial nutrient-enriched inorganic substrate and on the same substrate to which an organic sediment from a eutrophic lake was added, at three different water depth treatments. Growth decreased, and proportional allocation of biomass to roots increased, with the addition of sediment. These differences were significant in shallow and deep water, but not at a medium depth. Concentrations of phosphorus and nitrogen in plant biomass decreased, and concentration of iron increased, with addition of sediment. The effects of sediment addition may have resulted from a decreased availability of nutrients in the substrate or from an impaired root functioning. Nutrient exhaustion in the substrate, due to a fast plant growth, can explain the relatively strong effects in shallow water. Deep water, on the other hand, probably restricted oxygen transport to the roots, resulting in an impaired root functioning in the low-redox sediment environment. The results show that, especially in relatively deep water, growth of undisturbed plants of P. australis may be inhibited by eutrophication of sediments, probably because of an impaired root functioning in sediments containing reduced toxic compounds (e.g. ferrous iron). |
| Title: Patterns of variation in the acoustic calling signals of Chloriona planthoppers (Homoptera: Delphacidae) coexisting on the common reed Phragmites australis. |
| Author: Gillham-Malcolm-C; De-Vrijer-Peter-W-F. |
| Source: Biological-Journal-of-the-Linnean-Society. 1995; 54 (3) 245-269. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Populations of the four species of Chloriona commonly found in the Netherlands-C. dorsata, C. glaucescens, C. smaragdula and C. vasconica-were cultured in the laboratory on Phragmites australis, their exclusive host plant in the field. The low frequency substrate-transmitted signals produced during the calling phase of mating behaviour were digitally analysed for the mates and females of each species. Variables selected to cover most aspects of the call were measured, and variation was quantified within species and statistically tested among species using univariate and multivariate techniques. The calls of the males were more complex in structure than those of the females, with two different phase patterns recognized, and were species-specific. C. glaucescens and C. vasconica were also separated on variables of the female call, but C. dorsata and C. smaragdula completely overlapped. No significant differences were found between the calls of the long-winged and short-winged female morphs of C. smaragdula. A possible role for variation in calling signals, and responses to them, in the evolution and maintenance of reproductive isolation in Chloriona is discussed. |
| Title: Growth and trace metal absorption by Phragmites australis in wetlands constructed for landfill leachate treatment. 4. International INTECOL Wetlands Conference, Symposium on the Role of Vegetation in Created and Restored Wetlands, Columbus, OH (USA), 13- |
| Author: Peverly,-J.H.; Surface,-J.M.; Wang,-Tiangen. |
| Source: ECOL.-ENG. 1995 vol. 5, no. 1, pp. 21-35. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Phragmites australis (common reed) grew well in the presence of high concentrations of NH sub(4) super(+)-N (300 mg/l), BOD (300 mg/l), Fe (30 mg/l), Mn (1.5 mg/l) and K (500 mg/l). Other metals were not particularly elevated with the pH of the landfill leachate being 7-7.2. Reed standing crop continued to increase in the two years after leachate applications began, ranging to about 1100, 100, and 1000 g/m super(2) dry wt. for shoots, roots and rhizomes, respectively. Nutrient elements like N, K, Ca, and Mg were absorbed to normally sufficient levels, while tissue P was low at 0.04%. Metals were not translocated to and accumulated by shoots or rhizomes, but exhibited elevated levels in roots. Fe, Cu, Zn, Pb, and Cd were at levels of 3700, 65, 45, 12 and 0.2 mg/kg respectively, but the roots acted as effective filters for transport of metals to the shoots and rhizomes. Only P and Zn accumulation by plants approached total amounts in leachate entering the constructed beds. SEM and X-ray microanalysis showed Fe accumulation on root surfaces, with Fe and other metals at lower concentrations inside the root tissue. The rhizosphere may provide a particularly effective, locally oxidized environment for metal precipitation and adsorption outside the root. |
| Title: [Comparative analysis of NPK nutrient content of Iris pseudacorus, Phragmites australis, Scirpus lacustris and Typha latifolia.]. Analisis comparado del contenido en nutrientes NPK de Iris pseudacorus, Phragmites australis, Scirpus lacustris y Typha latif |
| Author: Ansola-Gonzalez,-G.; Gonzalez-Martin,-J.M.; Fernandez-Alaez,-C.; De-Luis-Calabuig,-E. |
| Source: STUD.-OECOL. 1995 no. 12, pp. 41-48. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: The NPK contents in the leafs, stems and fruits of four macrophytes species (Iris pseudacorus, Phragmites australis, Scirpus lacustris and Typha latifolia) was determinated, assessing the associated chaning with the plant fenology. The nutrients assimilation capacity according with the macrophyte species it is analyzed as well as the accumulation level of them in the different parts of the plant. The potassium (K) was measured by selective electrode analysis, to determinate the phosphorous (P) was used the method proposed by Duque (1971) and the nitrogen (N) analysis was made with Kjeldahl method. |
| Title: Vertical zonation and production rates of epiphytic algae on Phragmites australis. |
| Author: Mueller-Ute. |
| Source: Freshwater-Biology. 1995; 34 (1) 69-80. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: The vertical distribution of chlorophyll in epiphyton on Phragmites australis showed a peak in the middle sections of the submerged parts. Just below the water surface and above the sediment, chlorophyll concentrations were much less. During winter and early spring, loosely attached diatoms were predominant just below the water surface and on the middle sections of the Phragmites plants. Near the bottom, adnate diatoms, parenchymatous thalli of chlorophytes and cyanobacteria were abundant. At high photosynthetic active radiation (Phragmites australisR) during May, filamentous species of Ulothricophyceae and Zygophyceae developed dense populations on the middle sections of the stems. Primary production rate was proportional to chlorophyll concentration although production maxima were recorded above the biomass maxima. Where illumination was low, the chlorophyll-specific rate of photosynthesis (P-B rate) decreased proportionally with the vertical decrease of Phragmites australisR in the littoral zone, independent of the chlorophyll concentration on the stems. When illumination was high, the P-B rate decreased as biomass increased, and was independent of surface radiation. The dependence of primary production rate on chlorophyll concentration produced a saturation curve with a maximum production at 4.6 mu-gC cm-2 h-1. |
| Title: Ramet size equalisation in a clonal plant, Phragmites australis. |
| Author: Ekstam-B. |
| Source: Oecologia-Berlin. 1995; 104 (4) 440-446. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: The influence of shading from older generations of dead culms (standing litter) on density, growth rate and development of size structure at the ramet level was investigated in a pure stand of Phragmites australis by experimental neutral shading of plots after removal of standing litter. Initial differences in height distribution between autumn and spring cohorts disappeared in the course of shoot growth. The Gini coefficients of shoot heights and estimated shoot weights indicated that the size structure of the shoots became more equal with increasing mean size in both shaded and unshaded plots. Relative growth rate for height (RHGR) and weight of individual shoots was negatively related to shoot size during the early and presumably storage-dependent growth period, suggesting a strong support for growth of smaller shoots. No etiolation was indicated by mean or maximum height in shaded and unshaded plots, or by the relationship between shoot height and weight. Mean shoot density was significantly lower in shaded than in unshaded plots in one of two shade treatment years. A regression model indicated a small but significant effect of shoot density on the approximately linear relationship between RHGR and the logarithm of height. The growth rate of small shoots was slightly larger at low than at high shoot density. Therefore, it is suggested that the shade from standing litter in P. australis stands can decrease shoot natality in the spring cohort, and thereby increase the support to fewer small shoots. |
| Title: Occurrence and physiological properties of epiphytic bacteria isolated from reed (Phragmites australis (Cav) Trin. ex Steudel). |
| Author: Donderski-Wojciech; Lalke-Elzbieta. |
| Source: Acta-Universitatis-Nicolai-Copernici-Prace-Limnologiczne. 1995; 0 (18) 13-24. |
| Source Type: Journal |
| Publication Date: 1995 |
| Abstract: Studies were conducted on the occurrence and physiological properties of epiphytic bacteria inhabiting submerged parts of reed stems over the plant's developmental cycle. The maximum numbers of epiphytic bacteria were found in autumn, the minimum in spring. The predominant forms among the morphological types of the strains were Gram negative rods; they accounted for 51.0-68.0% of the total of epiphytic bacteria. The most numerous were bacteria of the groups Arthrobacter - Corynebacterium and Achromobacter, and the least numerous were those of the genus Bacillus. Among the most common physiological properties of the studied bacteria was the ability to decompose pectin and chitin. |
| Title: Seasonal variation of epiphytic extracellular enzyme activity on two freshwater plants, Phragmites australis and Elodea canadensis. |
| Author: Chappell-K-R; Goulder-R. |
| Source: Archiv-fuer-Hydrobiologie. 1994; 132 (2) 237-253. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Extracellular enzyme activity of epiphyton on submerged surfaces of Phragmites australis and Elodea canadensis, and in surrounding water, was measured in a gravel-pit pond in NE England. Epiphytic enzyme activity was greater per unit dry weight of E. canadensis, but was greater on P. australis when expressed on a plant surface area basis. The ranking of the enzymes assayed was the same on both host plants and in the pond water, i.e. phosphatase gt beta-D-glucosidase gt beta-D-galactosidase and beta-D-xylosidase gt sulphatase. Values of epiphytic enzyme activity relative to activity in pond water were substantial enough to suggest that, at well vegetated sites, epiphytic enzyme activity should make up an appreciable proportion of whole-pond extracellular enzyme activity. Epiphytic enzyme activity on P. australis varied seasonally, with summer maxima, whereas there was no obvious seasonal periodicity on E. canadensis. Multiple-regression analysis suggested that enzyme activity on P. australis was potentially dependent on both epiphytic bacterial variables (metabolic activity and abundance) and characteristics of the surrounding water (pH and temperature). In contrast, enzyme activity on E. canadensis was apparently more dependent on surrounding water quality. |
| Title: Phragmites australis (P. communis): Threats, management, and monitoring. |
| Author: Marks-Marianne ; Lapin-Beth; Randall-John. |
| Source: Natural-Areas-Journal. 1994; 14 (4) 285-294. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: NA |
| Title: Seasonal development of epiphytic algae on Phragmites australis (CAV.) TRIN. ex STEN. in a eutrophic lake. |
| Author: Mueller-Ute. |
| Source: Archiv-fuer-Hydrobiologie. 1994; 129 (3) 273-292. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: The epiphytic algal community on Phragmites australis was characterized by chlorophyll concentrations and biovolume throughout three annual cycles in the eutrophic Lake Belau (Schleswig-Holstein, Germany). During the investigation period, from November 1988 till October 1991 there were prominent spring maxima in March and April. A second but shorter peak was observed in May 1989 and June 1991. During the summer, the least amount of periphyton biomass was found on the stems. Throughout the year, the diatoms usually accounted for the most biovolume. Only in late spring or early summer, when the Phragmites australisR (photosynthetic active radiation) was greatest within the Phragmites belt, they were displaced by chlorophytes. Only low volumes of cyanobacteria were present, and this group was never predominant. Adnate bacillariophyceaen and chlorophyceaen species were predominated during fall and winter, and loosely attached species displaced them during the other seasons. Biomass production and algal succession displaced great regularity throughout the three years of the investigation. |
| Title: Seasonal dynamics of aufwuchs Naididae (Oligochaeta) on Phragmites australis in a eutrophic lake. 5. Int. Symp. on Aquatic Oligochaetes: Aquatic Oligochaete Biology 6, Stroemstat (Sweden), 5-10 Sep 1994. |
| Author: Loehlein,-B. |
| Source: HYDROBIOLOGIA 1996 vol. 334, no. 1-3, pp. 115-132. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: The Oligochaeta and Aphanoneura in the aufwuchs on Phragmites australis in a eutrophic hardwater lake were studied at two sites over a period of one year, in order to elucidate the structure and dynamics of this assemblage. The naidids Chaetogaster diastrophus, Nais spp., and Stylaria lacustris dominated the assemblage at any season. At both sites these taxa showed the same distinct pattern of successive population maxima in spring and summer: Chaetogaster diastrophus reached its peak density first, followed by Nais species, and eventually by Stylaria lacustris. Differences in temporal dynamics between sites were small apart from a second Stylaria maximum which was only observed at one site. Total naidid densities reached peak values of 3.8 individuals per cm super(2) reed stem surface area. With mean individual biomass of 2.2 mu g dry mass for Chaetogaster diastrophus, 13.3 mu g for Nais, and 86 mu g for Stylaria lacustris, respectively, maximum total naidid biomass on reed stems was 44 mu g dry mass per cm super(2). The biomass peak occurred later than that of total naidid density because in summer larger naidids dominated the assemblage. The observed succession appears to be consistent with seasonal changes in periphytic algal communities on the reed stems. |
| Title: The use of DNA fingerprinting in ecological studies of Phragmites australis (Cav.) Trin. ex Steudel. |
| Author: Zeidler-A; Schneider-S; Jung-C; Melchinger-A-E; Dittrich-P. |
| Source: Botanica-Acta. 1994; 107 (4) 237-242. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: A number of reed populations (Phragmites australis) from natural locations on the shore of Lake Ammersee in the south of Bavaria as well as artificially grown reed plants were analyzed for restriction fragment length polymorphisms (RFLPs) in order to evaluate for further ecological studies the dynamics of the restriction pattern within the genome of plants which propagate themselves asexually. The artificially grown reed plants were raised in four ponds supplemented with different phosphate concentrations (8 mu-g, 16 mu-g, 50 mu-g, and 200 mu-g/l) from rhizomes taken from a neighbouring fish pond. The genomic DNA of 25 of these plants and the DNA from 37 plants out of 18 stands from the lakeshore was isolated and restricted with the enzyme EcoRI, EcoRV, XbaI and HindIII and hybridized to three probes from a shot-gun cloned reed plasmid library. The probes gave between 15 and 26 bands (DNA fingerprints) of high polymorphic frequency (68%-100%) after hybridization with repetitive sequences of restricted DNA. A cluster analysis based on the banding pattern as a measure of genetic similarity (GS) was performed with the two sets of reed plants. The plants from the lakeshore exhibited a clear formation of clusters with GS up to 100%; the 20 plants grown from rhizomes, in contrast, did not show any clear correlation among themselves, neither to the phosphate concentration they grew in, nor to the five plants tested from the pond their rhizomes came from. The value of genetical investigations of the plant genome in context with environmental impact on plants is being discussed. |
| Title: Distribution and growth of the helophyte species Phragmites australis and Scirpus lacustris in water depth gradients in relation to wave exposure. |
| Author: Coops-Hugo ; Geilen-Noel; Van-Der-Velde-Gerard. |
| Source: Aquatic-Botany. 1994; 48 (3-4) 273-284. |
| Source Type: Journal |
| Publication Date: 1994 |
| Abstract: Interaction effects of water depth and exposure to wind-generated waves on the growth of two helophyte species, Phragmites australis (Cav.) Trin. ex Steudel and Scirpus lacustris L. were investigated. The colonization by P. australis of the shoreline of Lake Volkerak, a former estuarine branch transformed into a freshwater lake, correlated strongly with wave exposure. A transplantation experiment was performed to measure growth responses of P. australis and Scirpus lacustris to water depth and exposure gradients. The experiment showed that the wave action influenced biomass production, tiller formation and tiller height for both species in the lower part of the shoreline elevational gradient. Both species performed well at three positions along the sheltered gradient, but growth in deeper water was strongly reduced in the exposed gradient. This reduction was greater for Scirpus lacustris than for P. australis. The importance of differences in stem stiffness of the species and consequences for the shoreline vegetation zonation are discussed. |
| Title: Influence of submergence on growth of seedlings of Scirpus lacustris and Phragmites australis. |
| Author: Weisner,-S.E.B.; Graneli,-W.; Ekstam,-B. |
| Source: FRESHWAT.-BIOL. 1993. vol. 29, no. 3, pp. 371-375. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Seeds of Scirpus lacustris and Phragmites australis were germinated in early June, and twenty-four seedlings of each species were subsequently exposed to submerged conditions (eight seedlings at each of the water depths 0.2, 0.4 and 0.8 m), in outdoor 500-1 tanks in southern Sweden. Weight and shoot length of the plants were measured in September. The Phragmites seedlings did not show any significant growth when submerged. The Scirpus seedlings, however, developed submerged leaves and exhibited considerable submerged growth. One Scirpus plant, in shallow water (0.2 m), had developed an aerial shoot by September. Shoot length of the remaining (submerged) Scirpus plants was positively related to plant weight within water depth treatments, and was higher, in relation to plant weight, in deeper water. Mean weight in September of the submerged Scirpus plants decreased with increased water depth. In south Swedish lakes with a lowered water table, Scirpus often occupies large areas on the lakeward side of the reed belt, which is generally dominated by Phragmites . The differences between the two species, in performance of submerged seedlings, suggest that this zonation may be created through successful submerged seedling establishment of Scirpus on the lakeward side of Phragmites . |
| Title: Influence of submergence on growth of seedlings of Scirpus lacustris and Phragmites australis. |
| Author: Weisner-Stefan-E-B; Graneli-Wilhelm; Ekstam-Borje. |
| Source: Freshwater-Biology. 1993; 29 (3) 371-375. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: 1. Seeds of Scirpus lacustris and Phragmites australis were germinated in early June, and twenty-four seedlings of each species were subsequently exposed to submerged conditions (eight seedlings at each of the water depths 0.2, 0.4 and 0.8 m), in outdoor 500-l tanks in southern Sweden. Weight and shoot length of the plants were measured in September. 2. The Phragmites seedlings did not show any significant growth when submerged. The Scirpus seedlings, however, developed submerged leaves and exhibited considerable submerged growth. One Scirpus plant, in shallow water (0.2 m), had developed an aerial shoot by September. Shoot length of the remaining (submerged) Scirpus plants was positively related to plant weight within water depth treatments, and was higher, in relation to plant weight, in deeper water. Mean weight in September of the submerged Scirpus plants decreased with increased water depth. 3. In south Swedish lakes with a lowered water table, Scirpus often occupies large areas on the lakeward side of the reed belt, which is generally dominated by Phragmites. The differences between the two species, in performance of submerged seedlings, suggest that this zonation may be created through successful submerged seedling of establishment of Scirpus on the lakeward side of Phragmites. |
| Title: Growth dynamics and size structure of shoots of Phragmites australis, a clonal plant. |
| Author: Hara-T ; Van-Der-Toorn-J; Mook-J-H. |
| Source: Journal-of-Ecology. 1993; 81 (1) 47-60. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Growth dynamics and size structure during one growing season were investigated at the level of the individual shoot of Phragmites australis, a clonal plant. These were based on the diffusion model for three shoot populations which are described as even-aged sparse (the least crowded), even-aged dense and uneven-aged dense (the most crowded). Irrespective of the difference in the degree of crowdedness, these three shoot populations converged to the same size structure in height and weight as they grew, suggesting a regulatory mechanism between shoots. There was no growth in shoot diameter, and hence size-structure dynamics of shoot height and weight were almost parallel. From these size-structure dynamics and from direct estimation of the growth pattern of shoots for the sparse shoot population, two types of shoot growth pattern were inferred for the uneven-aged dense shoot population of Phragmites australis which consisted of young small replacement and old established shoots: type 1 has a linear G(t,x) function (mean of absolute growth rates of shoots of size x at times t in the diffusion model) with respect to x together with the size-independent D(t,x) function (variance of absolute growth rates of shoots of size x at time t in the diffusion model) whereas type 2 has a concave G(t,x) function with respect to x and/or positive growth rate for the smallest shoot in the stand (in this case, the functional effects of D(t,x) are generally small). In both cases growth of small young shoots is guaranteed or supported but not suppressed by large old shoots either stochastically (type 1) or deterministically (type 2), thus leading to little variability in shoot size, even in the uneven-aged crowded stand which can be regarded as an extreme situation of asymmetric competition. These growth patterns and size-structure dynamics are in striking contrast to those of non-clonal plants, which generally have a convex G(t,x) function with respect to x and a positively size-dependent D(t,x) function, and thus greater size variability under more crowded conditions, especially in uneven-aged stands consisting of small young and large old individuals. These differences suggest physiological integration between shoots in Phragmites australis. The size-independent D(t,x) function is common to many clonal plant species including Phragmites australis, whilst the G(t,x) function differs between species. This suggests that effective physiological integration between shoots works at least stochastically in the growth dynamics of shoots in many clonal plant species (and in some clonal species, deterministically as well), at least in the form of a controlled allocation of remobilized resources from the rhizomes to the growing shoots especially at the early growing stage. It was also inferred that the stochasticity in growth of small shoots plays an important role in the establishment and persistence of clonal plants. |
| Title: Primary production measurements on Phragmites australis (Cav.) Trin. ex Steud. in the Elbe estuary. |
| Author: Seelig-Annette. |
| Source: Archiv-fuer-Hydrobiologie-Supplementband. 1993; 75 (3-4) 325-340. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Primary production was estimated for Phragmites australis (Cav.) Trin. ex Steud. in the middle and lower section of the Elbe estuary. In the freshwater and in the brackish tidal marsh (oligohaline and beta-mesohaline) selected transects were sampled during two vegetation periods utilizing a multiple harvest method (SMALLEY 1959). Net aerial primary production (NAPP) and vegetation turnover times were calculated from biomass yield. NAPP values ranged from 2018 g cntdot m-2 cntdot yr-1 to 2881 g cntdot m-2 cntdot yr-1 and exceeded peak standing crop of life material by 29% to 72%. Vegetation turnover times were defined as maximum total aerial biomass divided by NAPP (GORDON et al., 1985), and were estimated to be 440 days, 378 days, and 403 days for the freshwater, the oligo- and the beta-mesohaline section, respectively (1988). Results are compared to other production measurements and the importance of the marsh production to the Elbe ecosystem is discussed. |
| Title: Growth dynamics and size structure of shoots of Phragmites australis , a clonal plant. |
| Author: Hara,-T.; Toorn,-J.-van-der; Mook,-J.H. |
| Source: J.-ECOL. 1993. vol. 81, no. 1, pp. 47-60. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Growth dynamics and size structure during one growing season were investigated at the level of the individual shoot of Phragmites australis , a clonal plant. These were based on the diffusion model for three shoot populations which are described as even-aged sparse (the least crowded), even-aged dense and uneven-aged dense (the most crowded). Irrespective of the difference in the degree of crowdedness, these three shoot populations converged to the same size structure in height and weight as they grew, suggesting a regulatory mechanism between shoots. From these size-structure dynamics and from direct estimation of the growth pattern of shoots for the sparse population, two types of shoot growth pattern were inferred for the uneven-aged dense shoot population of Phragmites australis which consisted of young small replacement and old established shoots: type 1 has a linear G(t,x) function (mean of absolute growth rates of shoots of size x at time t in the diffusion model) with respect to x together with the size-independent D(t,x) function (variance of absolute growth rates of shoots of size x at time t in the diffusion model) whereas type 2 has a concave G(t,x) function with respect to x and/or positive growth rate for the smallest shoot in the stand (in this case, the functional effects of D(t,x) are generally small). |
| Title: Response of Phragmites australis to water stress from flooding to drought. |
| Author: Elhaak-M-A; El-Din-A-Sharaf; Sammour-R-H. |
| Source: Pakistan-Journal-of-Botany. 1993; 25 (1) 41-46. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Leaf samples of Phragmites australis collected from five locations varying from totally flooded to dry regime showed a sharp decrease in the fresh leaf water content of the plant from flooding to dry locations accompanied by an incomparable decrease in OP. This incremental osmotic regulation occurred due to the accumulation of soluble sugars, amino acids, proteins, proline and the nutrient elements K, Na, Ca, Mg and Fe. Low OP under flooding was attributed to the condensation of sugars and amino acids into polysaccharides and protein. Both drought and flooding conditions resulted in the accumulation of polysaccharides, protein and proline. |
| Title: Seasonal nitrogen dynamics in reed beds (Phragmites australis (Cav.) Trin. ex. Steudel) in relation to productivity. |
| Author: Kuehl,-H.; Kohl,-J.-G. |
| Source: Phosphorus and Nitrogen Dynamics and Retention in Ecotones of Lowland Temperate Lakes and Rivers, Masurian Lakeland (Poland), 20-26 May 1991. NUTRIENT-DYNAMICS-AND-RETENTION-IN-LAND-WATER-ECOTONES-OF-LOWLAND,-TEMPERATE-LAKES-AND-RIVERS. Hillbricht-Ilkows |
| Source Type: Book |
| Publication Date: 1993 |
| Abstract: Shoot biomass and nitrogen, accumulated within above-ground plant biomass in autumn, correlate with nitrogen availability indicated by nitrogen content (% DM) of several shoot parts during the height of the growth period. A higher nitrogen percentage of the shoots is correlated with a higher shoot loss and subsequent substitution by branching and tillering during and continuing toward the end of the growth period. A delayed switch from the vegetative to the generative phase reduces the translocation of reserve material to the rhizome. Increasing nitrogen load is at least one of the factors causing instability and reed-belt decline. |
| Title: Probable effects of algal bloom on the growth of Phragmites australis (Cav.) Trin. ex Steud. |
| Author: Yamasaki-Shiori. |
| Source: Journal-of-Plant-Research. 1993; 106 (1082) 113-120. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: The effects of blue-green algal blooms on an emergent reed plant, Phragmites australis (Cav.) Trin, ex Steud., were investigated in a eutrophic lake in central Japan. The plants showed conspicuous withering of bottom leaves in spring in 1982, after an early occurrence of the bloom. In June, the plants in the area of algal infestation had about half the shoot length and dry weight of normal P. australis without the algal infestation. Reductions in water transparency, dissolved oxygen in bottom water and redox potentials of surface soil corresponded to the presence of algal bloom and plant damage. |
| Title: Influence of germination time on juvenile performance of Phragmites australis on temporarily exposed bottoms--implications for the colonization of lake beds. |
| Author: Weisner,-S.E.B.; Ekstam,-B. |
| Source: AQUAT.-BOT. 1993. vol. 45, no. 2-3, pp. 107-118. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Three cohorts of seedlings of Phragmites australis (Cav.) Trin ex Steud., germinated in May, June and July, were allowed to grow in shallow water (depth 5 cm or less) in southern Sweden. In the autumn, size parameters were measured on the plants. In the second year, the water level was raised to 0.8 m and emergence of shoots, plant survival and size parameters were recorded. The mean plant weight by the end of the first year differed markedly between cohorts. Rhizome biomass showed a relationship of 700:70:1 between the May, June and July cohorts. In the second year, rate of emergence above the water surface, and maximum height of plants that did not reach the water surface, was positively related to the size (mass) the plants had achieved after the first year. Only plants that emerged above the water surface survived the second summer, resulting in survival rates for the May, June and July cohorts of 90%, 685 and 0%, respectively. The rhizome weight of the smallest survivors had decreased after the second summer compared with values after the first summer. Hence, they were not capable of "reloading" their rhizomes during the second year. In a temperate climate, the size of juvenile plants after the first year, which is strongly dependent on early germination on exposed bottoms (i.e. bottom without standing water), determines their water depth tolerance during the second year. The timing and duration of exposure, as well as the subsequent depth or re-flooding, are all of fundamental importance for successful "lakeward" seedling expansion of P. australis . |
| Title: Phragmites australis in Quebec: Geographic distribution, chromosome numbers and reproduction. |
| Author: Gervais-C ; Trahan-R; Moreno-D; Drolet-A-M. |
| Source: Canadian-Journal-of-Botany. 1993; 71 (10) 1386-1393. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: A study of Phragmites australis (Cav.) Trin. ex Steud., the common reed, was conducted in Quebec between 1985 and 1991. Its present and former geographical distributions (before and after 1950) were established, the chromosome numbers of 52 individuals were determined, and various observations on the reproduction of this species by seed were made. The geographical distribution was outlined after consultation of 21 north-eastern american herbaria and upon in situ observations along roadsides in most parts of inhabited Quebec. Concurrently, 77 representative populations were selected and visited in the summer and fall of 1985, allowing the observation of the degree of flower development, the frequency of seed setting, and the presence of smut, Claviceps microcephala (Wallr.) Tul. The chromosome numbers show a high degree of aneuploidy and vary between 2n = 42 and 59. The nordic populations tend to have a lower chromosome number and a faster flower development. In fact, for a given geographical area and date of collection, the flowers of the individuals with higher chromosome numbers are usually less developed. There is however a persistent problem with the evaluation of the chromosome number of a stand because of internal variations. Seed production is generally very low, but some stations, even nordic, are quite productive (up to 59.2% of flowers with seeds). The seeds are able to germinate under laboratory conditions, but it is not known yet if the plant can reproduce in this manner in the field. The seedlings develop slowly and seem to have poor competitiveness. |
| Title: A physical model involving Nucleopore membranes to investigate the mechanism of humidity-induced convection in Phragmites australis. |
| Author: Armstrong-J; Armstrong-W. |
| Source: Proceedings-of-the-Royal-Society-of-Edinburgh-Section-B-Biological-Sciences. 1993 (1994); 102 (0) 529-539. |
| Source Type: Paper |
| Publication Date: 1993 |
| Abstract: NA |
| Title: Distribution of heavy metals accumulated in Phragmites australis in delta zones of the northern Black Sea coast. |
| Author: Nebesnyy,-V.B.; Dubyna,-D.V.; Prokopenko,-V.F.; Shelyag-Sosonko,-Yu.R. |
| Source: HYDROBIOL.-J.;GIDROBIOL.-ZH.-KIEV 1993;1992 vol. 29, no. 2, pp. 9-21, vol. 28, no. 1, pp. 98-108. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Areal differences in the levels of heavy metals accumulated by Phragmites australis in the delta zones of the Danube (Kiliy Branch), Dniester, Dnieper, and Kuban rivers are identified. High total concentrations of lead and molybdenum are found in Ph. australis aggregations along the Danube, high levels of manganese in the Kuban delta zone, high levels of copper and nickel in the Dniester delta, and high levels of zinc in the Dnieper delta. |
| Title: The relationship between starch content in rhizomes of Phragmites australis (Cav.) Trin. ex Steud. and trophic conditions of habitat. |
| Author: Kubin-P; Melzer-A; Cizkova-H. |
| Source: Proceedings-of-the-Royal-Society-of-Edinburgh-Section-B-Biological-Sciences. 1993 (1994); 102 (0) 433-438. |
| Source Type: Paper |
| Publication Date: 1993 |
| Abstract: The hypothesis of reed decline being a consequence of eutrophication has been proved. Rhizomes of P. australis from two habitats differing in nutrient availability were collected during one year. In the nutrient-poor habitat, less aboveground biomass and greater starch reserves were formed in comparison with the nutrient-rich one. In the stand with a high nutrient availability, a decrease in starch content was observed in horizontal rhizomes during autumn. |
| Title: Vascular system of male and perfect florets of Phragmites australis (Gramineae-arundinoideae). |
| Author: Pizzolato-Thompson-Demetrio. |
| Source: International-Journal-of-Plant-Sciences. 1993; 154 (1) 119-133. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: The vascular system in the male and perfect florets of Phragmites of the grass subfamily Arundinoideae was reconstructed from serial cross sections. Components of the vascular system in both florets are nearly alike but for differences related to the presence of the gynoecium. The two collateral traces from the styles merge with the collateral placental bundles to form an amphicribral bundle, the pistil prong, in the ovary below the ovule. The prong descends into the upper plexus, an amphicribral bundle formed by the merging stamen traces in the rachilla. A xylem discontinuity occurs in the placental bundle and in the distal upper plexus. The collateral lodicule traces enter the rachilla and unite with the proximal portion of the upper plexus as the palea traces merge into them. But after contacting the upper plexus, the lodicule traces are again discrete in their continued descent of the rachilla. The two lodicule traces, the three lemma traces, and the three traces from the rachilla extension distal to the floret are all discrete bundles in the rachilla of the floret base. Using Phragmites to represent the Arundinoideae in a comparison of floret vascular systems of subfamilies indicates a close relationship between Arundinoideae and Chloridoideae. The combination of features from the floret vascular systems of these subfamilies bridges the Pooideae and the Panicoideae. |
| Title: Influence of germination time on juvenile performance of Phragmites australis on temporarily exposed bottoms: Implications for the colonization of lake beds. |
| Author: Weisner-Stefan-E-B ; Ekstam-Borje. |
| Source: Aquatic-Botany. 1993; 45 (2-3) 107-118. |
| Source Type: Journal |
| Publication Date: 1993 |
| Abstract: Three cohorts of seedlings of Phragmites australi2 (Cav.) Trin ex Steud., germinated in May, June and July, were allowed to grow in shallow water (depth 5 cm or less) in southern Sweden. In the autumn, size parameters were measured on the plants. In the second year, the water level was raised to 0.8 m and emergence of shoots, plant survival and size parameters were recorded. The mean plant weight by the end of the first year differed markedly between cohorts. Rhizome biomass showed a relationship of 700:70:1 between the May, June and July cohorts, In the second year, rate of emergence above the water surface, and maximum height of plants that did not reach the water surface, was positively related to the size (mass) the plants had achieved after the first year. Only plants that emerged above the water surface survived the second summer, resulting in survival rates for the May, June and July cohorts of 90%, 68% and 0%, respectively. The rhizome weight of the smallest survivors had decreased after the second summer compared with values after the first summer. Hence, they were not capable of 'reloading' their rhizomes during the second year. In a temperature climate, the size of juvenile plants after the first year, which is strongly dependent on early germination on exposed bottoms (i.e. bottoms without standing water), determines their water depth tolerance during the second year. The timing and duration of exposure, as well as the subsequent depth of re-flooding, are all of fundamental importance for successful 'lakeward' seedling expansion of P. australis. |
| Title: Territorial differentiation of phosphorus accumulated by Phragmites australis (Cav.) Trin. ex Steud. in estuarine areas of rivers of the northern Black Sea region. |
| Author: Nebesnyi-V-B; Dubyna-D-V; Shelyag-Sosonko-Yu-R. |
| Source: Ekologiya-Moscow. 1992; 0 (5) 90-92. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: NA |
| Title: Geobotanical and resource characteristics of Phragmites australis (Cav.) Trin. ex Steud in the region of the Danube outfall. |
| Author: Dubyna-D-B ; Nebesnyi-V-B; Prokopenko-V-F. |
| Source: Ukrayins'kyi-Botanichnyi-Zhurnal. 1992; 49 (1) 87-94. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Phragmites australis (Cav.) Trin ex Steud. has been studied for the peculiarities of its present day distribution in the region of the Danube outfall, its ecologo-botanical and resourse characteristics have been presented. The areas occupied by the Ph. australis communications as well as their total productivity has been established to increase and this is stipulated by the intensification of the overgrowth processes in the shallow water areas as a result of a decrease of the total watering of the flooded areas. Problems of rational use and protection of Ph. australis resources have been elucidated. |
| Title: The effects of salinity and flooding on Phragmites australis. |
| Author: Hellings,-S.E.; Gallagher,-J.L. |
| Source: J.-APPL.-ECOL. 1992. vol. 29, no. 1, pp. 41-49. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Phragmites australis buds with attached rhizomes were planted in PVC tubes and grown under various salinity and flooding conditions in a greenhouse for one growing season. P. australis buds did not emerge from cores flooded to the soil surface, regardless of salinity, indicating a possible lack of oxygen transport to below-ground structures. Density, height and biomass were all negatively affected by increasing salinity (0, 15 and 30 g/l), as were recoverable underground reserves (RUR) and rhizome non-structural carbohydrate concentration (RNCC). Height, biomass, RUR and RNCC decreased with increased flooding level (20 and 10 cm of the core above water level). The results suggest that it may be possible to control P. australis stands in marshes by controlling water tables/flooding and salinity levels. |
| Title: Morphological, karyological and enzymatic variability among some populations of Phragmites australis (Cav.) Trin. ex Steud. |
| Author: Djebrouni-Mohamed. |
| Source: Folia-Geobotanica-et-Phytotaxonomica. 1992; 27 (1) 49-59. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Use of morphological, karyological and enzymatic approaches in the study of 11 populations of Phragmites australis (CAV.) TRIN. ex STEUD. originating from different geographic areas, climates and ecological conditions reveals a spatial differentiation of populations. There is no relationship between the two levels of ploidy, 2n = 48 and 2n = 96, and the habitat. In contrast, the climate and environmental conditions act to the selection of the well-adapted genotypes. So, the considerable phenotypic variability of P. australis is due to a high adaptability and an important genetic diversity. |
| Title: Decomposition and nutrient dynamics of reed (Phragmites australis (Cav.) Trin. ex Steud.) litter in Lake Neusiedl, Austria. |
| Author: Hietz,-P. |
| Source: AQUAT.-BOT. 1992. vol. 43, no. 3, pp. 211-230. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Common reed leaf and stalk litters were exposed in coarse (5 mm) and fine (70 mu m) mesh bags at five sites from the landward to the lakeward margin of the reed belt of Lake Neusiedl, Austria. Additionally, some samples were exposed above water and in a reedless pool. After 863 days, leaves exposed below water had lost-51-85% of the original ash-free dry weight, depending on site and bag mesh size. Weight losses of stalks and of litter exposed above water were considerably smaller (15-32%). Decomposition was fastest at the lakeward site, slowest in the middle of the reed belt, and intermediate at the landward site. This rate correlated with concentrations of N, P, K and Ca, which were high after a short time in the litter at sites with higher decomposition rates. Leaves collected from one site and exposed at others showed that decomposition rates depended on site characteristics rather than on initial litter quality. Nutrient concentrations (N, P, K, Na, Ca and Mg), except of Fe, decreased during the first month, and all, including Fe, increased subsequently until the end of the study period. Increases in N and P seem to be controlled mainly by uptake by litter-settling micro-organisms. |
| Title: Leafminers (Diptera; Agromyzidae) of Phragmites australis in Belgium. |
| Author: Scheirs-Jan; De-Bruyn-L. |
| Source: Bulletin-and-Annales-de-la-Societe-Royale-Belge-d'Entomologie. 1992 (1993); 128 (10-12) 310-315. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: During 1991, leafmines on Phragmites australis were collected at different localities in Belgium. Four different species of Agromyzidae were reared: Agromyza hendeli, Agromyza phragmitidis, Cerodontha (Poemyza) incisa and Cerodontha (Poemyza) phragmitidis. All species recorded are new to the Belgian fauna. The larval biology of each species is briefly discussed. |
| Title: Germination under various culture conditions of reed caryopses (Phragmites australis (Cav.) Trin. ex Steud.) from Lake Patnowskie (near Konin, Poland) with heated water. |
| Author: Kraska-Marek ; Podolski-Grzegorz; Podolska-Magdalena. |
| Source: Acta-Hydrobiologica. 1992; 34 (3) 213-225. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Non-uniform germination of reed caryopses (from 0% for most samples to over 90%) at relatively stable temperatures (21 +- 1.9 degree C and 31.7 +- 1.0 degree C) and constant light was observed. On the average 70% of caryopses (panicles) kept in room conditions for 3, 5, 10, 20, 40, and 120 days from harvest showed a loss of the ability to germinate only in conditions of culture with a small amplitude of temperature variations (21 +- 1.9 degree C). |
| Title: Early withering of lower leaves of Phragmites australis (Cav.) Trin. ex Steud. in a eutrophic stand: Role of oxygen concentration, fate of nitrogen and nitrogen uptake by the plants. |
| Author: Yamasaki,-S.; Kimura,-M.; Yoneyama,-T. |
| Source: AQUAT.-BOT. 1992. vol. 42, no. 2, pp. 143-157. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: The maximum nitrogen uptake activity of Phragmites australis (Cav.) Trin. ex Steud. was observed in mid-May. Aquatic (adventitious) and soil roots absorbed nitrate or ammonium at equal rates under aerobic conditions. After 6-10 h incubation of roots in an open chamber with a stirred medium, dissolved oxygen was reduced almost to zero, probably due to root respiration. It is suggested that the uptake of ammonium by plants was slowed down and that nitrate was lost rapidly under these conditions. The use of super(15)N showed that very little nitrate was taken up by P. australis , as compared to ammonium. These results suggest that an important cause of withering of the lower leaves was oxygen deficiency brought about by a blue-green algal bloom, which was followed by nitrogen deficiency of P. australis . The latter resulted from low ammonium uptake and a large loss of nitrate through denitrification around the aquatic roots. |
| Title: Distribution of heavy metals accumulated by the reed Phragmites australis (Cav.) Trin. ex Steud. in estuarine areas of rivers of the northern Black Sea region. |
| Author: Nebesnyi-V-B; Dubyna-D-V; Prokopenko-V-F; Shelyag-Sosonko-Yu-R. |
| Source: Gidrobiologicheskii-Zhurnal. 1992; 28 (1) 98-108. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: The territorial differentiation of heavy metals accumulated by Phragmites australis (Cav.) Trin. ex Steud. in the estuarine regions of the Danube (the Kiliian arm). Dniester, Dnieper, Kuban rivers has been determined. High bulk composition of lead and molybdenum is typical of Ph. australis aggregations in the Danube, manganese-in the estuarine region of the Kuban, copper and nickel-in the estuarine region of the Dniester and zinc-in the estuarine region of the Dnieper (Russia). |
| Title: Decomposition and nutrient dynamics of reed (Phragmites australis (Cav.) Trin ex Steud.) litter in Lake Neusiedl, Austria. |
| Author: Hietz-Peter. |
| Source: Aquatic-Botany. 1992; 43 (3) 211-230. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Common reed leaf and stalk litters were exposed in coarse (5 mm) and fine (70 mu-m) mesh bags at five sites from the landward to the lakeward margin of the reed belt of Lake Neusiedl, Austria. Additionally, some samples were exposed above water and in a reedless pool. After 863 days, leaves exposed below water had lost 51-85% of the original ash-free dry weight, depending on site and bag mesh size. Weight loss of stalks and of litter exposed above water were considerably smaller (15-32%). Decomposition was fastest at the lakewater site, slowest in the middle of the reed belt, and intermediate at the landward site. This rate correlated with concentrations of N, P, K and Ca, which were high after a short time in the litter at sites with higher decomposition rates. Leaves collected from one site and exposed at others showed that decomposition rates depended on site characteristics rather than on initial litter quality. Nutrient concentrations (N, P, K, Na, Ca and Mg), except of Fe, decreased during the first month, and all, including Fe, increased subsequently until the end of the study period. Changes of cation concentrations can generally be explained by cation exchange processes. Photosynthesis of epiphytes, carbonate precipitation and sediment incorporation can account for some of the changes observed. Increases in N and P, in contrast, seem to be controlled mainly by uptake by litter-settling micro-organisms. Of the various mathematical models tested, one including a temperature-independent labile fraction and a temperature-dependent recalcitrant fraction was the most successful. |
| Title: Nitrogen accumulation, productivity and stability of reed stands (Phragmites australis (Cav.) Trin. ex Steudel) at different lakes and sites of the lake districts of Uckermark and Mark Brandenburg (Germany). |
| Author: Kuehl,-H.; Kohl,-J.-G. |
| Source: INT.-REV.-GESAMT.-HYDROBIOL. 1992. vol. 77, no. 1, pp. 85-107. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: The extent of decline of reed belts (Phragmites australis ) during last decades has been established by using aerial photographs of the mesotrophic lake Parsteiner See and the eutrophic lake Mueggelsee. Final standing crop and nitrogen accumulation within the above-group plant biomass of 15 different sites of 8 lakes correlate with nitrogen availability indicated by both dissolved nutrient content of the sediment and nitrogen content of biomass during the main growth period. Reed stands well supplied with nitrogen show high shoot loss and compensatory tiller growth till late in the season. Some results demonstrate a delayed switching from the vegetative phase to the generative one and lowered allocation of reserve material to the rhizome as at least one of the factors responsible for lowering stability of the reed beds. |
| Title: A chromosome study in intraspecific polyploidy of Phragmites australis and its related species. |
| Author: Zong,-Weixing; Chen,-Ruiyang; Taniguchi,-K.; Kondo,-K. |
| Source: KROMOSOMO. 1991. vol. 2, no. 63-64, pp. 2168-2172. |
| Source Type: Journal |
| Publication Date: 1991 |
| Abstract: An intraspecific polyploid series was found in Phragmites australis in China with tetraploid (2n = 48), hexaploid (2n = 72) and octoploid (2n = 96). The most common plants of this species were of octoploid. Both Phragmites japonica and P. karka were of tetraploid. |
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