Search

Vertical flow-constructed wetlands (VFCWs) are treatment systems that can be used for the phytoremediation of highly polluted textile wastewater. Using plant-derived biochar to simultaneously improve the contaminant removal performance of CWs and sustainable utilization of harvested plant biomass is an interesting proposition. The present study explored the phytoremediation potential of Phragmites karka and verified the impact of using P. karka-derived biochar as a substrate in VFCWs for the treatment of textile wastewater. For this, three types of VFCWs were designed; (i) non-vegetated (VFCW), (ii) vegetated with P. karka (VFCW-P), and (iii) vegetated with P. karka and amended with P. karka-derived biochar (VFCW-BP) and semi-batch experiments were conducted. The investigation confirmed that wetlands using biochar as substrate were more efficient than other wetlands in pollutant load reduction. The maximum pollutant removal efficiencies were recorded for VFCW-BP vis-à-vis COD (83.61%), color (77.87%), chloride (73.22%), calcium (73.52%), sodium (67.18%), and potassium (75.72%) after five days. Furthermore, biochar addition enhanced the growth conditions for wetland plants by alleviating osmotic and oxidative stresses and hence helped them to perform better while removing pollutants. The maximum reduction of various pollutant parameters was reached within 72 h, after which remediation efficiency was slowed down. The study suggests that VFCW with biochar amendment is a useful strategy for textile wastewater treatment. Because the experimental design satisfies the needs for low-cost wastewater treatment, it may find widespread applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Phragmites australis is a widespread invasive plant species in the USA that greatly impacts estuarine wetlands by creating dense patches and outcompeting other plants. The invasion of Phragmites into wetland ecosystems is known to decrease biodiversity, destroy the habitat of threatened and endangered bird species, and alter biogeochemistry. While the impact of Phragmites is known, the spatial extent of this species is challenging to document due to its fragmented occurrence. Using high-resolution imagery from the National Agriculture Imagery Program (NAIP) from 2017, we evaluated a geospatial method of mapping the spatial extent of Phragmites across the state of DE. Normalized difference vegetation index (NDVI) and principal component analysis (PCA) bands are generated from the NAIP data and used as inputs in a random forest classifier to achieve a high overall accuracy for the Phragmites classification of around 95%. The classified gridded dataset has a spatial resolution of 1 m and documents the spatial distribution of Phragmites throughout the state's estuarine wetlands (around 11%). Such detailed classification could aid in monitoring the spread of this invasive species over space and time and would inform the decision-making process for landscape managers., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Invasion of plant species with functional traits that influences the rhizosphere can have significant effects on soil organic matter (SOM) dynamics if the invasive species stimulates soil microbial communities with, for example, an enhanced supply of labile carbon and oxygen. We evaluated these effects along a Phragmites invasion chronosequence spanning over 40 years. Using a δ 13 C and δ 15 N enriched substrate, we separated SOM-derived and substrate-derived carbon (C) and nitrogen (N) mineralization in surface (top 15 cm), shallow (30-45 cm), and deep (65-80 cm) soils collected from established, newly invaded, and native plant communities. We found all soils were susceptible to SOM priming, but priming profiles differed between vegetation communities, being highest at the surface in native assemblage soils, whereas highest at depth under invasive plants. Changes in functional microbial community composition at depth in Phragmites soils, evidenced by an increase in relative fungal laccase abundance, explained the SOM priming in these deep invaded soils. Our results show that invasive Phragmites maintains a microbial community at depth able to degrade SOM faster than that under native vegetation, evidencing that plant species shifts can fundamentally change soil biogeochemistry, altering element cycling and decreasing SOM residence time. Furthermore, our experimental design allowed to quantify real-time SOM-C and SOM-N gross mineralization, resulting in a new model relating C and N mineralization in these wetland soils and providing new insights on how SOM decomposition impacts N availability and cycling across wetland N pools., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

There is increasing evidence that global change can alter ecosystems by eliciting rapid evolution of foundational plants capable of shaping vital attributes and processes. Here we describe results of a field-scale exposure experiment and multilocus assays illustrating that elevated CO 2 (eCO 2 ) and nitrogen (N) enrichment can result in rapid shifts in genetic and genotypic variation in Phragmites australis, an ecologically dominant plant that acts as an ecosystem engineer in coastal marshes worldwide. Compared to control treatments, genotypic diversity declined over three years of exposure, especially to N enrichment. The magnitude of loss also increased over time under conditions of N enrichment. Comparisons of genotype frequencies revealed that proportional abundances shifted with exposure to eCO 2 and N in a manner consistent with expected responses to selection. Comparisons also revealed evidence of tradeoffs that constrained exposure responses, where any particular genotype responded favorably to one factor rather than to different factors or to combinations of factors. These findings challenge the prevailing view that plant-mediated ecosystem outcomes of global change are governed primarily by differences in species responses to shifting environmental pressures and highlight the value of accounting for organismal evolution in predictive models to improve forecasts of ecosystem responses to global change., Competing Interests: Declaration of competing interest The authors have no competing interests to declare., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Salt marsh vegetation zones shift in response to large-scale environmental changes such as sea-level rise (SLR) and restoration activities, but it is unclear if they are good indicators of soil nitrogen removal. Our goal was to characterize the relationship between denitrification potential and salt marsh vegetation zones in tidally restored and tidally unrestricted coastal marshes, and to use vegetation zones to extrapolate how SLR may influence high marsh denitrification at the landscape scale. We conducted denitrification enzyme activity assays on sediment collected from three vegetation zones expected to shift in distribution due to SLR and tidal flow restoration across 20 salt marshes in Connecticut, USA (n = 60 sampling plots) during the summer of 2017. We found lower denitrification potential in short-form Spartina alterniflora zones (mean, 95% CI: 4, 3-6 mg N h -1  m -2 ) than in S. patens (25, 15-36 mg N h -1  m -2 ) and Phragmites australis (56, 16-96 mg N h -1  m -2 ) zones. Vegetation zone was the single best predictor and explained 52% of the variation in denitrification potential; incorporating restoration status and soil characteristics (soil salinity, moisture, and ammonium) did not improve model fit. Because denitrification potential did not differ between tidally restored and unrestricted marshes, we suggest landscape-scale changes in denitrification after tidal restoration are likely to be associated with shifts in vegetation, rather than differences driven by restoration status. Sea-level-rise-induced hydrologic changes are widely observed to shift high marsh dominated by S. patens to short-form S. alterniflora. To explore the implications of this shift in dominant high marsh vegetation, we paired our measured mean denitrification potential rates with projections of high marsh loss from SLR. We found that, under low and medium SLR scenarios, predicted losses of denitrification potential due to replacement of S. patens by short-form S. alterniflora were substantially larger than losses due to reduced high marsh land area alone. Our results suggest that changes in vegetation zones can serve as landscape-scale predictors of the response of denitrification rates to rapid changes occurring in salt marshes., (© 2022 The Authors. Ecological Applications published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)

Increasing generation of wastewater and its indiscriminate disposal is detrimental to human and animal health. Resource-limited settings often struggle for efficient wastewater treatment systems owing to lack of funds and operational difficulties. Therefore, alternative treatment systems involving low expenditure and simplistic operations are need of the hour. Constructed wetlands are one such alternative that can efficiently remove variety of pollutants from wastewater. In this study, we have assessed the utility of constructed wetlands for treatment of hospital wastewater in Ujjain. An in-house wetland system was designed and constructed using Typha latifolia and Phragmites karka. Results showed that wetland was efficient for removal of various physico-chemical and biological contaminants, namely, biochemical-oxygen-demand (77.1%), chemical-oxygen-demand (64.9%), turbidity (68.3%), suspended-solids (63%), total-phosphorus (58.7%), nitrate-nitrogen (33%), fecal coliforms (96.8%), and total coliforms (95.6%). Paired t test revealed that removal efficiencies for various parameters were significantly different among Phragmites, Typha, and control cells (p ≤ 0.05). Study also depicted that most of the bacterial isolates in inlet wastewater were selectively resistant to antibiotics (ciprofloxacin and sulphamethaxazole) as well and these isolates were also removed. Precisely, Typha was fairly suitable for antibiotic resistant bacteria removal. Thus, constructed wetlands were found to be one of the suitable options for wastewater treatment in resource-limited settings. PRACTITIONER POINTS: Constructed wetlands are one of the suitable options for wastewater treatment in resource limited settings. These systems involve wetland vegetation, soil, and associated microbial assemblages to improve the water quality. Typha and Phragmites were found to be efficient for treating the hospital wastewater. Experiments showed that antibiotic resistant bacteria may also be removed through constructed wetland systems. Easy operation, cost effectiveness, and efficiency are important attributes., (© 2022 The Authors. Water Environment Research published by Wiley Periodicals LLC on behalf of Water Environment Federation.)

Saline tidal wetlands are important sites of carbon sequestration and produce negligible methane (CH 4 ) emissions due to regular inundation with sulfate-rich seawater. Yet, widespread management of coastal hydrology has restricted tidal exchange in vast areas of coastal wetlands. These ecosystems often undergo impoundment and freshening, which in turn cause vegetation shifts like invasion by Phragmites, that affect ecosystem carbon balance. Understanding controls and scaling of carbon exchange in these understudied ecosystems is critical for informing climate consequences of blue carbon restoration and/or management interventions. Here, we (1) examine how carbon fluxes vary across a salinity gradient (4-25 psu) in impounded and natural, tidally unrestricted Phragmites wetlands using static chambers and (2) probe drivers of carbon fluxes within an impounded coastal wetland using eddy covariance at the Herring River in Wellfleet, MA, United States. Freshening across the salinity gradient led to a 50-fold increase in CH 4 emissions, but effects on carbon dioxide (CO 2 ) were less pronounced with uptake generally enhanced in the fresher, impounded sites. The impounded wetland experienced little variation in water-table depth or salinity during the growing season and was a strong CO 2 sink of -352 g CO 2 -C m -2  year -1 offset by CH 4 emission of 11.4 g CH 4 -C m -2  year -1 . Growing season CH 4 flux was driven primarily by temperature. Methane flux exhibited a diurnal cycle with a night-time minimum that was not reflected in opaque chamber measurements. Therefore, we suggest accounting for the diurnal cycle of CH 4 in Phragmites, for example by applying a scaling factor developed here of ~0.6 to mid-day chamber measurements. Taken together, these results suggest that although freshened, impounded wetlands can be strong carbon sinks, enhanced CH 4 emission with freshening reduces net radiative balance. Restoration of tidal flow to impounded ecosystems could limit CH 4 production and enhance their climate regulating benefits., (© 2022 John Wiley & Sons Ltd. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Wetland plants tolerate potentially hazardous metals through a variety of strategies, including exclusion or accumulation. Whether plants sequester metals and where they store them in their tissues is important for understanding the potential role of plants as remediators or vectors of metals to terrestrial food webs. Here we evaluate metal sequestration in Great Salt Lake wetlands for one invasive (Phragmites australis; phragmites) and three native plant species, i.e. threesquare bulrush (Schoenoplectus americanus), hardstem bulrush (Schoenoplectus acutus), alkali bulrush (Bolboschoenus maritimus), and their terrestrial invertebrates. We observed higher concentrations of arsenic and copper than other metals in plant tissues, although high lead concentrations were observed in phragmites. All plants acted as excluders of arsenic and selenium, retaining the bulk of the metal mass in belowground tissues. In contrast, lead, copper, and cadmium were transferred to above ground tissues of hardstem bulrush and phragmites. The aboveground translocation facilitated the movement of these metals into invertebrates, with the highest concentrations in most cases found in predators. Though our results highlight the potential for metal remediation via wetland plant growth and removal, care should be taken to ensure that remediation efforts do not lead to bioaccumulation., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The application of Phragmites australis based constructed wetlands (CW) have been widely used in various climates and also used for secondary treatment of diverse wastewater and polluted water. This work compares the treatment performance of two Phragmites-based mesocosms: the first with surface horizontal flow (SF), and the other with subsurface horizontal flow (SSF), in the same conditions of feeding and climate. The results showed a significantly high mineral content of the effluent water exiting SSF-CW. The last one was significantly more efficient in terms of removal of Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), Total Nitrogen (TN), ammonium (NH 4 -N), and Total Phosphorus (TP) compared to SF-CW, i.e. 26.3, 3.12, 1.59, and 0.62 g. m -2 . day -1 in the same order. The microbiological load reduction is also significantly higher in SSF-CW. On the contrary, the other parameters of pollution monitored do not allow the identification of a significant difference between SF- and SSF-CW. The atmospheric evapotranspiration value was higher in SSF-CW by 24.8 ± 20 mm. d -1 , corresponding also to a higher harvestable biomass of Phragmites of 58.2 t. ha -1 . year -1 ., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Polyploidization in plants is thought to have occurred as coping mechanism with environmental stresses. Polyploidization-driven adaptation is often achieved through interplay of gene networks involved in differentially expressed genes, which triggers the plant to evolve special phenotypic traits for survival. Phragmites australis is a cosmopolitan species with highly variable phenotypic traits and high adaptation capacity to various habitats. The species' ploidy level varies from 3x to 12x, thus it is an ideal organism to investigate the molecular evolution of polyploidy and gene regulation mediated by different numbers of chromosome copies. In this study, we used high-throughput RNAseq data as a tool, to analyze the gene expression profiles in tetraploid and octoploid P. australis . The estimated divergence time between tetraploid and octoploid P. australis was dated to the border between Pliocene and Pleistocene. This study identified 439 up- and 956 down-regulated transcripts in tetraploids compared to octoploids. Gene ontology and pathway analysis revealed that tetraploids tended to express genes responsible for reproduction and seed germination to complete the reproduction cycle early, and expressed genes related to defense against UV-B light and fungi, whereas octoploids expressed mainly genes related to thermotolerance. Most differentially expressed genes were enriched in chaperones, folding catalysts and protein processing in endoplasmic reticulum pathways. Multiple biased isoform usage of the same gene was detected in differentially expressed genes, and the ones upregulated in octoploids were related to reduced DNA methylation. Our study provides new insights into the role of polyploidization on environmental responses and potential stress tolerance in grass species., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Wang, Wang, Yin, Eller, Liu, Brix and Guo.)

So far, research on plant-associated macroinvertebrates, even if conducted on a large number of water bodies, has mostly focused on a relatively small area, permitting limited conclusions to be drawn regarding potentially broader geographic effects, including climate. Some recent studies have shown that the composition of epiphytic communities may differ considerably among climatic zones. To assess this phenomenon, we studied macroinvertebrates associated with the common reed Phragmites australis (Cav.) Trin. ex Steud in 46 shallow lakes using a common protocol. The lakes, located in nine countries, covered almost the entire European latitudinal range (from <48°N to 61°N) and captured much of the variability in lake size and nutrient content in the region. A Poisson Generalized Linear Mixed Model (GLMM) showed the number of macroinvertebrate epiphytic taxa to be negatively associated with water conductivity and positively associated with medium ice cover duration (approximately 1 month). A Gamma GLMM showed a positive effect of chlorophyll a on the density of macroinvertebrates, and a significantly greater density in lakes located at the lowest and highest latitudes. Individual taxa responded differently to lake environmental conditions across climate zones. Chironomidae dominated in all climate zones, but their contribution to total density decreased with increasing latitude, with progressively greater proportions of Naidinae, Asellidae, Ephemeroptera and Trichoptera. Our study demonstrates that epiphytic macroinvertebrate fauna, even when analyzed at low taxonomic resolution, exhibits clear differences in diversity, relative abundance of individual taxa and total density, shaped both by geographic and anthropogenic variables. The results were discussed in the context of climate change. To our best knowledge this is the first study to examine epiphytic fauna carried out on a European scale., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

Salinity is a crucial environmental problem leading to profound consequences in wetland plants and aquatic habitats including the rapid development of Phragmites australis in the marshland. These Phragmites australis are extremely vulnerable to capture fire, which might eventually affect the overall ecosystem of the marsh. However, in order to restore the marsh, a hydrologic investigation is needed, which is possible if a watershed is gauged, and long-term data are available. In this study, a systematic approach has been presented to conduct hydrologic modeling and salinity prediction in an ungauged watershed in order to implement the possible removal of salt fill sites. The stage and electrical conductivity were measured continuously, whereas stream cross sections and velocity of the streamflow were recorded intermittently in the Blackbrook Creek to develop a rating curve and generate continuous streamflow data. The watershed model Soil and Water Assessment Tool (SWAT) was calibrated and validated to a monthly scale with good model performance. In the next step, critical sources of salinity were identified from the two tributaries in order to implement the removal of salt fill sites for the possible reduction of salinity in the marsh. While salinity loading was approximately 10 times higher from Marsh Creek (65.63 tons to 2028.13 tons per month) compared with Blackbrook Creek (10.23 tons to 163.98 per month), the analysis suggested that salinity concentration was higher from Blackbrook Creek, which was particularly due to abandoned salt fill sites near the Creek. The salinity loadings were linearly correlated with streamflow on a monthly (R 2  = 0.81) scale, which was utilized to generate the salinity loadings that were diverted due to the rerouting of the Creek through the new location in order to avoid salt fill sites and reduce salinity in the Mentor Marsh. Our analysis suggested that approximately 74 kg/day salinity was being rerouted from the Marsh; however, the salt fill sites contribute salinity to the Marsh equivalent to 63 kg/day, which still needs to be removed. The research findings are expected to be helpful for monitoring small ungauged watersheds.

The root of Phragmites australis can often be used as the Chinese herb in China. In this paper, the complete chloroplast genome of P. australis was studied for more genetic information. The chloroplast genome was 137,561 bp in length as the circular and typical quadripartite structure, which contained a large single-copy region (LSC) of 82,328 bp, a small single-copy region (SSC) of 12,699 bp, and a pair of inverted-repeat regions (IRs) of 21,267 bp. The overall nucleotide composition of chloroplast genome is: 42,300 bp A (30.7%), 42,090 bp T (30.6%), 26,500 bp C (19.3%), 26,671 bp G (19.4%) and the total G + C content of 38.7%. However, 134 genes were found that included 87 protein-coding genes (PCGs), 39 transfer RNA (tRNAs), and 8 ribosome RNA (rRNAs). The Maximum-Likelihood (ML) method phylogenetic relationship with the reported chloroplast genomes showed that Phragmites australis is closely related to Setaria viridis and Setaria italic of the family Poaceae., Competing Interests: The authors have declared that no competing interests exist., (© 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

Species interactions that influence the performance of the exotic mosquito Culex pipiens can have important effects on the transmission risk of West Nile virus (WNV). Invasive plants that alter the vegetation communities of ephemeral ground pools may facilitate or resist the spread of C. pipiens (L.) by altering allochthonous inputs of detritus in those pools. To test this hypothesis, we combined field surveys of roadside stormwater ditches with a laboratory microcosm experiment to examine relationships between C. pipiens performance and water quality in systems containing detritus from invasive Phragmites australis (Cav.) Trin. Ex Steud., introduced Schedonorus arundinaceus (Schreb.) Dumort., or native Juncus effusus L. or Typha latifolia L. In ditches, C. pipiens abundance was unrelated to detritus species but female C. pipiens were significantly larger from ditches with S. arundinaceus and smaller with J. effusus . Larger and smaller C. pipiens were also produced in microcosms provisioned with S. arundinaceus and J. effusus, respectively, yet the per capita rate of population of change did not vary. Larger females from habitats with S. arundinaceus were likely caused by faster decay rates of S. arundinaceus and resultant increases in microbial food, but lower survival as a result of fouling and higher tannin-lignin concentrations resulted in little changes to overall population performance. Larger female mosquitoes have been shown to have greater potential for transmitting arboviruses. Our findings suggest that changed community-level interactions from plant invasions in urban ephemeral ground pools can affect the fitness of C. pipiens and possibly increase WNV risk.

Cadmium (Cd) toxicity in agricultural crops is a widespread problem. Little is known about biochar and arbuscular mycorrhizal fungi (AMF) effect on Cd concentration in maize plant either applied separately or in combination. Current study was performed to demonstrate effects of biochar and Rhizophagus clarus on plant growth, photosynthesis activity, nutrients (P, Ca, Mg, Fe, Cu, and Mn), and Cd concentration in maize grown in Cd-spiked soil. The alkaline soil was spiked by Cd factor at three levels: 0 (Cd 0), 5 (Cd 5), and 10 (Cd 10) mg/kg; biochar factor at two levels: 0 and 1%; and mycorrhizal inoculum factor at two levels: MF0 and MF1 (R. clraus). Plants were harvested after 70 days of seed germination, and various morphological and physiological parameters, as well as elemental concentration and root colonization, were recorded. Addition of biochar increased plant biomass by 21% (Cd 5) and 93% (Cd 10), MF1 enhanced by 53% (Cd 0) and 69% (Cd 10), while biochar + MF1 enhanced dry plant biomass by 70% (Cd 0) and 94% (Cd 10). Results showed maximum increase of 94% (Cd 10) in plant biomass was observed in Cd-spiked soil. Root colonization decreased proportionally by increasing Cd concentration and at Cd 10, colonization was 36.7% and 31.7% for MF1 and biochar + MF1 treatments, respectively. Besides that, addition of biochar enhanced root attributes (root length, volume, and surface area) by 34-58% compared to control in Cd 10. The MF1 increased these attributes by 11-78% while biochar + MF1 enhanced by 32-61% in Cd-spiked soil. However, biochar + MF1 neutralized Cd stress in maize plant for gaseous attributes (assimilation rate, transpiration rate, intercellular CO 2 , and stomatal conductance). The MF1 enhanced Cd concentration in plant as it was 3.32 mg/kg in Cd 5 and 6.73 mg/kg in Cd 10 treatments while addition of biochar phytostabilized Cd and reduced its concentration in plants by 2.0 mg/kg in Cd 5 and 4.27 mg/kg in Cd 10. The biochar + MF1 had 2.9 mg/kg and 4.8 mg/kg Cd concentration in Cd 5 and Cd 10 plants, respectively. Phosphorus concentration was augmented in shoots (up to 26%) and roots (up to 20%) of maize plant in biochar-amended soil than control plants. In biochar + MF1, concentration of P was 1.01% and 0.73% in Cd 5 and Cd 10, respectively. It is concluded that biochar + MF1 treatment enhances plant biomass while addition of sole biochar reduced Cd uptake, slightly indifferent to earlier treatment.

In situ amendment of sediments with highly sorbent materials like activated carbon (AC) is an increasingly viable strategy to reduce the bioavailability of persistent, sediment-associated contaminants to benthic communities. Because in situ sediment remediation is an emerging strategy, much remains to be learned about the field conditions under which amendments can be effective, the resilience of amendment materials toward extreme weather conditions, and the optimal design of engineered applications. We report the results of a multiyear, pilot-scale field investigation designed to measure the persistence and efficacy of AC amendments to reduce the bioavailability of polychlorinated biphenyls (PCBs) in an intertidal Phragmites marsh. The amendments tested were granular AC (GAC), GAC with a layer of sand, and a pelletized fine AC. Key metrics presented include vertically resolved black carbon concentrations in sediment and PCB concentrations in sediment, porewater, and several invertebrate species. The results demonstrate that all 3 amendments withstood Hurricane Sandy and remained in place for the duration of the study, successfully reducing porewater PCB concentrations by 34 to 97%. Reductions in invertebrate bioaccumulation were observed in all amendment scenarios, with pelletized fine AC producing the most pronounced effect. The present findings support the use of engineered AC amendments in intertidal marshes and can be used to inform amendment design, delivery, and monitoring at other contaminated sediment sites. Environ Toxicol Chem 2018;37:2496-2505. © 2018 SETAC., (© 2018 SETAC.)

Phragmites australis and Typha latifolia are two macrophytes commonly present in natural and artificial wetlands. Roots of these plants engage in interactions with a broad range of microorganisms, collectively referred to as the microbiota. The microbiota contributes to the natural process of phytodepuration, whereby pollutants are removed from contaminated water bodies through plants. The outermost layer of the root corpus, the rhizoplane, is a hot-spot for these interactions where microorganisms establish specialized aggregates designated biofilm. Earlier studies suggest that biofilm-forming members of the microbiota play a crucial role in the process of phytodepuration. However, the composition and recruitment cue of the Phragmites , and Typha microbiota remain poorly understood. We therefore decided to investigate the composition and functional capacities of the bacterial microbiota thriving at the P. australis and T. latifolia root-soil interface. By using 16S rRNA gene Illumina MiSeq sequencing approach we demonstrated that, despite a different composition of the initial basin inoculum, the microbiota associated with the rhizosphere and rhizoplane of P. australis and T. latifolia tends to converge toward a common taxonomic composition dominated by members of the phyla Actinobacteria, Firmicutes, Proteobacteria, and Planctomycetes. This indicates the existence of a selecting process acting at the root-soil interface of these aquatic plants reminiscent of the one observed for land plants. The magnitude of this selection process is maximum at the level of the rhizoplane, where we identified different bacteria enriched in and discriminating between rhizoplane and rhizosphere fractions in a species-dependent and -independent way. This led us to hypothesize that the structural diversification of the rhizoplane community underpins specific metabolic capabilities of the microbiota. We tested this hypothesis by complementing the sequencing survey with a biochemical approach and scanning electron microscopy demonstrating that rhizoplane-enriched bacteria have a bias for biofilm-forming members. Together, our data will be critical to facilitate the rational exploitation of plant-microbiota interactions for phytodepuration.

Emergent aquatic macrophytes play an important role in the removal of nutrients in constructed wetlands (CWs). However, plant biomass supplies litter after the onset of senescence. Although litter-derived nitrogen (N) has been considered a nutrient source for the internal loading that may reduce CW performance, little is known about the quantitative N dynamics associated with litter decomposition. Thus, a controversial question remains about whether plant harvest is needed to manage CWs. In this study, we evaluated the decomposition and the fate of N derived from 15 N-labeled Phragmites litter in a CW for 1 year. To simulate respective natural conditions, two treatments, including (1) a single winter harvest and (2) no harvest where the latter supplies a greater stem litterfall, were compared. Although the dry weight of the added stem litter was approximately 4.7 times larger in the no harvest plot than in the harvest plot, the total N content of the initial 15 N-labeled litter was only 1.2 times higher in the no harvest plot than in the harvest plots because of the low N concentration in the stem litter. The litter functioned as a minor N sink within the first 6 months of decomposition, and it then shifted to functioning as a minor N source after 1 year of decomposition. The recovery of litter-derived N in the sediment and plant biomass was low (less than 10% of the initial litter N), and much of the remaining N might have been released into ambient water or lost through denitrification. Furthermore, our results suggested a potentially low contribution of litter-derived N to internal N loading for at least 1 year regardless of the harvest management treatment., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Introduced European genotypes of Phragmites australis are invasive and widespread in North America. Decades of management using herbicide and other means have failed to control the species and its range and populations continue to expand. Allowing continued invasion threatens native wetland biota and an endemic North American subspecies Phragmites australis americanus . The lack of conventional management to control introduced P. australis triggered research to assess host specificity of two European noctuid moths, Archanara geminipuncta and Archanara neurica . These two species are considered particularly promising potential biocontrol agents for introduced P. australis . Here we provide the complete and approved list of test plants used to assess host specificity of A. geminipuncta and A. neurica . This includes data on neonate larval acceptance and survival under no-choice conditions, and oviposition tests for all plant species tested, including for different Phragmites subspecies currently occurring in North America. We further provide temperature profiles of select cities in the temperate native European distribution of the two noctuids and those in southern US climates. We used these long-term temperature records to assess whether overwintering eggs of A. geminipuncta and A. neurica can survive under climate conditions typical for the Gulf Coast region in North America. This data article refers to "Host specificity and risk assessment of Archanara geminipuncta and Archanara neurica , two potential biocontrol agents for invasive Phragmites australis in North America Biol. Control (2018)".

The main pathways for phosphorus flux from land to sea are particle-associated (erosion) and dissolved runoff (rivers, groundwater, and agricultural drainage systems). These pathways can act as diffused sources for aquatic systems and support primary production, therefore, counteracting the efforts aimed at reducing phosphorus input from point sources such as sewage treatment plants. Phosphorus supports primary production in the water column and can elevate phytoplankton and macrophyte growth. Coastal wetlands with emerged (Phragmites australis) and submerged (Stuckenia pectinata and Chara sp.) macrophytes can affect phosphorus fluxes in the land-water transitional zone. The macrophytes have the potential to act as a buffer for phosphorus run-off. The aim of this study was to determine the phosphorus stocks in the transitional land-sea zone of a cold temperate lagoon at the southern Baltic Sea. Phosphorus in macrophytes, water samples, and phytoplankton growth were analyzed along a gradient moving away from the wetland. The phosphorus stocks in the above ground biomass of the Phragmites plants were the highest at the end of August and with more than 8000mgPm -2 in the interior zone of the wetland, threefold the amount of P in Phragmites plant tissue at the wetland fringe. The submerged macrophytes stored only 300mgPm -2 , close to the wetland. Concentrations of soluble reactive phosphorus in the water column were higher in the zones of emerged macrophytes than in the zones of submerged macrophytes and decreased along the land-sea transect. Phytoplankton could grow proximal to the wetland during all seasons, but not further away. This study indicates that macrophytes can act as phosphorus sinks. However, short-term releases of phosphate within the Phragmites wetland have the potential to lead to phytoplankton growth. Phytoplankton can use these nutrient pulses either immediately or later, and support high biomass and turbidity within the system., (Copyright © 2017. Published by Elsevier B.V.)

The tall-statured grasses in the genus Phragmites are dominant vegetation in wetlands worldwide and thus play a vital role in ecosystem functioning. As a result, Phragmites spp. are some of the most widely studied plants; particularly in areas where changes to their abundances have occurred, most notably in Europe and North America. In southern Africa a pattern of reed expansion has occurred in recent decades that has shown a similar trend to cryptic invasions reported in North America. This study used molecular techniques to explore the phylogeography of P. australis and P. mauritianus in the region to investigate whether the expansion is due to an alien invasion or local factors such as wetland disturbance. Three haplotypes were found and all haplotypes are presently considered African haplotypes (haplotype K for P. australis and haplotype V and AP for P. mauritianus ). Both Phragmites spp. were found to have high genetic diversity. Microsatellite and grass-waxy analysis also found evidence of hybridization between the two species. No evidence was found for a recent cryptic invasion of non-native haplotypes in southern Africa. The expansion of P. australis and P. mauritianus is therefore most likely a result of anthropogenic activity. Identifying and mitigating the human-mediated factors that may be contributing to reed growth, such as eutrophication and sedimentation, should be the focus of future management protocols.

A pilot experimental field combining rewetting of reclaimed peaty soils and water phyto-treatment was set up in the Massaciuccoli Lake basin (Tuscany, Italy) to reduce the water eutrophication and peat degradation caused by almost a century of drainage-based agricultural use. In this paper, we investigated the restoration process occurring consequently to the conversion of a drained area in a natural wetland system (NWS) (the partial top soil removal, the realization of a perimeter levee to contain the waters, the rewetting with the drainage waters coming from the of surrounding cultivated areas) and the capability of the spontaneous vegetation to catch nutrients acting as a vegetation filter. To follow the restoration process over time (2012-2016), we used a mixed approach merging phytosociological surveys with ortophotos taken by an Unmanned Aerial Vehicle (UAV). During the last year of observation (2016), we performed destructive sampling on the most widespread plant communities in the area (Phragmites australis and Myriophyllum aquaticum community) to quantify the biomass production and the uptake of nitrogen and phosphorus. Stands of Phragmites australis (Cav.) Trin. ex Steud. yielded more than Myriophyllum aquaticum (Vell.) Verdc. (4.94 kg m-2 vs 1.08 kg m-2). M. aquaticum showed higher nutrient contents (2.04% of N and 0.35% of P), however P. australis was able to take up more nutrients within the NWS because of its larger cover and productivity. In the perspective of maximizing the plant development and consequently the amount of nutrients extracted from treated waters, the authors suggest 4-5 year-long-harvesting turns, better occurring in spring-summer., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Identifying the factors that influence spatial genetic structure among populations can provide insights into the evolution of invasive plants. In this study, we used the common reed ( Phragmites australis ), a grass native in Europe and invading North America, to examine the relative importance of geographic, environmental (represented by climate here), and human effects on population genetic structure and its changes during invasion. We collected samples of P. australis from both the invaded North American and native European ranges and used molecular markers to investigate the population genetic structure within and between ranges. We used path analysis to identify the contributions of each of the three factors-geographic, environmental, and human-related-to the formation of spatial genetic patterns. Genetic differentiation was observed between the introduced and native populations, and their genetic structure in the native and introduced ranges was different. There were strong effects of geography and environment on the genetic structure of populations in the native range, but the human-related factors manifested through colonization of anthropogenic habitats in the introduced range counteracted the effects of environment. The between-range genetic differences among populations were mainly explained by the heterogeneous environment between the ranges, with the coefficient 2.6 times higher for the environment than that explained by the geographic distance. Human activities were the primary contributor to the genetic structure of the introduced populations. The significant environmental divergence between ranges and the strong contribution of human activities to the genetic structure in the introduced range suggest that invasive populations of P. australis have evolved to adapt to a different climate and to human-made habitats in North America.

The long-term (i.e., two consecutive annual cycles) ability of Phragmites australis to remediate estuarine sediments contaminated with heavy metals (Co, Ni, Mo, Cd, Pb, Cr, Cu, Fe, Mn, Zn and Hg) and trace elements of concern (As, Se, Ba) was investigated using an experimental approach on a pilot plant scale. The accumulation of these elements on belowground and aboveground tissues was monitored during vegetative and senescence periods for two populations of P. australis, originally from contaminated (MIC) and non-contaminated (GAL) estuaries, respectively. The initial concentration of the elements in the contaminated estuarine sediment decreased in the following order: Fe>Mn>Zn>Pb>Ba>Cr>As>Cu>Ni>Co>Mo>Cd>Se>Hg. A similar trend was recorded in the belowground biomass following remediation, suggesting the potential role of P. australis as an effective biomonitoring tool. Hg was not detected in any plant tissue. An overall annual increase of concentration levels in belowground tissue was observed. Overall, this study suggested that P. australis populations from GAL were substantially more efficient in taking up Ni, Mo and Cr during the second annual cycle in both belowground and aboveground tissue than P. australis populations from MIC. Calculated bio-concentration factors (BCF) suggested a clear metal excluder strategy for Co, Cd, Pb, Cu and Fe, with accumulation and stabilisation belowground, with limited translocation into aerial tissues observed during the length of this study. An excluder behaviour for Zn, Ba and Mn was detected during the second annual cycle, coinciding with a substantial increase of concentration levels belowground. This study demonstrated for the first time the long term efficacy of P. australis for phytoremediation of heavy metal contaminated estuarine sediments., (Copyright © 2016 Elsevier B.V. All rights reserved.)

After a long-term adaptation to desert environment, the perennial aquatic plant Phragmites communis has evolved a desert-dune ecotype. The desert-dune ecotype (DR) of Phragmites communis showed significant differences in water activity and protein distribution compared to its sympatric swamp ecotype (SR). Many proteins that were located in the soluble fraction of SR translocated to the insoluble fraction of DR, suggesting that membrane-associated proteins were greatly reinforced in DR. The unknown phenomenon in plant stress physiology was defined as a proteome translocation response. Quantitative 2D-DIGE technology highlighted these 'bound' proteins in DR. Fifty-eight kinds of proteins were identified as candidates of the translocated proteome in Phragmites . The majority were chloroplast proteins. Unexpectedly, Rubisco was the most abundant protein sequestered by DR. Rubisco activase, various chaperons and 2-cysteine peroxiredoxin were major components in the translocation response. Conformational change was assumed to be the main reason for the Rubisco translocation due to no primary sequence difference between DR and SR. The addition of reductant in extraction process partially reversed the translocation response, implying that intracellular redox status plays a role in the translocation response of the proteome. The finding emphasizes the realistic significance of the membrane-association of biomolecule for plant long-term adaptation to complex stress conditions.

Accumulation and/or degradation of Praziquantel (PZQ) in plants were determined using Phragmites australis, both suspension cultures and in vitro cultivated plants. In case of initial PZQ concentration 20mgL -1 , 90% was removed from liquid media within 21days. The accumulated PZQ was partly metabolized, twenty one compounds being identified, products of both Phase I and II of detoxification metabolism. Laboratory results were confirmed in real scale using the constructed wetland (CW), where PZQ (500mg in total) was completely removed until the first purification pond. This result offers a promising possibility to use CW for PZQ removal from agricultural as well as domestic waste-waters., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The effect of ferrous (added as FeCl2) on the anaerobic co-digestion of Phragmites straw and cow dung was studied by investigating the biogas properties, pH values, organic matter degradation (COD) and enzyme activities (cellulase, protease and dehydrogenase) at different stages of mesophilic fermentation. The results showed that Fe(2+) addition increased the cumulative biogas yields by 18.1 % by extending the peak period with high daily biogas yields. Meanwhile, the methane (CH4) contents in the Fe(2+) added groups were generally higher than the control group before the 15th day. The pH values were not significantly impacted by Fe(2+) concentrations during the fermentation process. The COD concentrations, cellulase, protease and dehydrogenase activities varied with the added Fe(2+) concentrations and the stages of the fermentation process. At the beginning stage of fermentation (4th day), Fe(2+) addition increased the biogas production by improving the cellulase and dehydrogenase activities which caused a decline in COD. At the peak stage of fermentation (8th day), Fe(2+) addition enhanced the cellulase and protease activities, and resulted in lower COD contents than the control group. When the biogas yields decreased again (13th day), the COD contents varied similar with the protease and dehydrogenase activities, whilst cellulase activities were not sensitive to Fe(2+) concentrations. At the end of fermentation (26th day), Fe(2+) addition decreased the cellulase activities, led to lower COD contents and finally resulted the lower biogas yields than the control group. Taking the whole fermentation process into account, the promoting effect of Fe(2+) addition on biogas yields was mainly attributed to the extension of the gas production peak stage and the improvement of cellulase activities.

The fitness costs of reproduction by clonal growth can include a limited ability to adapt to environmental and temporal heterogeneity. Paradoxically, some facultatively clonal species are not only able to survive, but colonize, thrive and expand in heterogeneous environments. This is likely due to the capacity for acclimation (sensu stricto) that compensates for the fitness costs and complements the ecological advantages of clonality. Introduced Phragmites australis demonstrates great phenotypic plasticity in response to temperature, nutrient availability, geographic gradient, water depths, habitat fertility, atmospheric CO2, interspecific competition and intraspecific competition for light. However, no in situ comparative subspecies studies have explored the difference in plasticity between the non-invasive native lineage and the highly invasive introduced lineage. Clonality of the native and introduced lineages makes it possible to control for genetic variation, making P. australis a unique system for the comparative study of plasticity. Using previously identified clonal genotypes, we investigated differences in their phenotypic plasticity through measurements of the lengths and densities of stomata on both the abaxial (lower) and adaxial (upper) surfaces of leaves, and synthesized these measurements to estimate impacts on maximum stomatal conductance to water (gwmax). Results demonstrated that at three marsh sites, invasive lineages have consistently greater gwmax than their native congeners, as a result of greater stomatal densities and smaller stomata. Our analysis also suggests that phenotypic plasticity, determined as within-genotype variation in gwmax, of the invasive lineage is similar to, or exceeds, that shown by the native lineage., (Published by Oxford University Press on behalf of the Annals of Botany Company.)

Monitoring of lakeshore ecosystems requires fine-scale information to account for the high biodiversity typically encountered in the land-water ecotone. Sentinel-2 is a satellite with high spatial and spectral resolution and improved revisiting frequency and is expected to have significant potential for habitat mapping and classification of complex lakeshore ecosystems. In this context, investigations of the capabilities of Sentinel-2 in regard to the spatial and spectral dimensions are needed to assess its potential and the quality of the expected output. This study presents the first simulation of the high spatial resolution (i.e., 10 m and 20 m) bands of Sentinel-2 for lakeshore mapping, based on the satellite's Spectral Response Function and hyperspectral airborne data collected over Lake Balaton, Hungary in August 2010. A comparison of supervised classifications of the simulated products is presented and the information loss from spectral aggregation and spatial upscaling in the context of lakeshore vegetation classification is discussed. We conclude that Sentinel-2 imagery has a strong potential for monitoring fine-scale habitats, such as reed beds.

A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis and Phragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management.

The ecological role of genome size in plant biology, biogeography, and morphology has garnered increasing attention as the methods and technology associated with measuring cytological characteristics have become more reliable and accessible. However, how plant genome size influences plant invasions and at what stage in the invasion this influence occurs have been little explored. Several large-scale analyses of published data have yielded valuable interspecific comparisons, but experimental studies that manipulate environmental factors are needed, particularly below the species level, to fully understand the role that genome size plays in plant invasion. In this review, we summarize the available knowledge, discuss the integration of genome size data into invasion research, and suggest how it can be applied to detect and manage invasive species. We also explore how global climate change could exert selective pressures on plant populations with varying genome sizes, thereby increasing the distribution range and invasiveness of some populations while decreasing others. Finally, we outline avenues for future research, including considerations of large-scale studies of intraspecific variation in genome size of invasive populations, testing the interaction of genome size with other factors in macroecological analyses of invasions, as well as the role this trait may play in plant-enemy interactions., (© 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.)

A potential dedicated energy crop (switchgrass) and an invasive (North America) plant species (phragmites) were compared as potential substrates for acetone butanol ethanol (ABE) fermentation. Both biomass were pretreated with 1% (w/v) NaOH and subjected to enzymatic hydrolysis. Total reducing sugar yields were 365 and 385gkg(-1) raw biomass for switchgrass and phragmites. Fermentation of the hydrolysates resulted in overall ABE yields of 146 and 150gkg(-1) (per kg dry plant material), with a theoretical maximum of 189 and 208gkg(-1), respectively. Though similar overall solvent yields were obtained from both crops, the largest carbon loss in the case of switchgrass occurred during pretreatment, while the largest loss in the case of phragmites occurred to enzymatic hydrolysis. These findings suggest that higher overall yields are achievable and that both crops are suitable feedstocks for butanol fermentation., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Unlabelled: •, Premise of the Study: The characteristics of clonal growth that are advantageous in invasive plants can also result in native plants' ability to resist invasion. In Maine, we compared the clonal architecture and diversity of an invasive lineage (introduced Phragmites) and a noninvasive lineage (native Phragmites) present in much of North America. This study is the first on stand-scale diversity using a sample size and systematic spatial-sampling scheme adequate for characterizing clonal structure in Phragmites. Our questions included: (1) Does the structure and extent of clonal growth suggest that the potential for clonal growth contributes to the invasiveness of the introduced lineage? (2) Is clonal growth common in the native lineage, acting as a possible source of ecological resistance and resilience?•, Methods: Microsatellite markers were used to measure clonal sizes, architecture, and diversity within each lineage in stands within four marshes in Maine.•, Key Results: Clonal diversity measures indicated that clonal growth was significantly greater in stands of the native lineage than in the introduced. While lineage was a consistent predictor of clonal diversity relative ranking, the marsh location was a much stronger predictor of the absolute range of these values.•, Conclusions: Our results indicate an important role for clonal growth in the space consolidation of native Phragmites and could explain why the introduced lineage, with stronger competitive traits, has not replaced the native where they co-occur. These results with regard to clone size, size distributions, singleton occurrence, and clonal architecture provide some evidence for stand development that follows a genotypic initial floristics model., (© 2014 Botanical Society of America, Inc.)

The energetic cost of plant organ construction is a functional trait that is useful for understanding carbon investment during growth (e.g. the resource acquisition vs. tissue longevity tradeoff), as well as in response to global change factors like elevated CO2 and N. Despite the enormous importance of roots and rhizomes in acquiring soil resources and responding to global change, construction costs have been studied almost exclusively in leaves. We sought to determine how construction costs of aboveground and belowground organs differed between native and introduced lineages of a geographically widely dispersed wetland plant species (Phragmites australis) under varying levels of CO2 and N. We grew plants under ambient and elevated atmospheric CO2, as well as under two levels of soil nitrogen. We determined construction costs for leaves, stems, rhizomes and roots, as well as for whole plants. Across all treatment conditions, the introduced lineage of Phragmites had a 4.3 % lower mean rhizome construction cost than the native. Whole-plant construction costs were also smaller for the introduced lineage, with the largest difference in sample means (3.3 %) occurring under ambient conditions. In having lower rhizome and plant-scale construction costs, the introduced lineage can recoup its investment in tissue construction more quickly, enabling it to generate additional biomass with the same energetic investment. Our results suggest that introduced Phragmites has had an advantageous tissue investment strategy under historic CO2 and N levels, which has facilitated key rhizome processes, such as clonal spread. We recommend that construction costs for multiple organ types be included in future studies of plant carbon economy, especially those investigating global change., (Published by Oxford University Press on behalf of the Annals of Botany Company.)

The heavy metal content and distribution in an urban wetland affected by combined sewer overflow (CSO) discharge during dry conditions was evaluated. Metals identified in the CSO discharge were also measured upstream and downstream of the CSO. Metals were detected in the acid-extractable fraction of the wetland sediments and the roots of Phragmites australis plants. Sediment from the banks of a pool created by the CSO, and from a clay bed upstream were found to be moderately contaminated with Cu, Pb and Zn. Micro X-ray fluorescence (μ-XRF) of Phragmites roots from the CSO banks showed a correlation in the spatial distribution of Fe and Mn, attributed to the formation of mineral plaques on the root surface. Micro X-ray absorption near edge spectroscopy (μ-XANES) revealed that Cu and Zn were complexed with the organic ligands phytate and cysteine. The findings indicated that continuous discharge from the CSO is a source of heavy metals to the wetland. Metals bound to sediments are susceptible to remobilization and subsequent transport, whereas those associated with Phragmites roots may be more effectively sequestered. These observations provide insight into the behavior of heavy metals in urban areas where CSOs discharge into wetlands., (Copyright © 2013. Published by Elsevier Ltd.)

Constructed wetlands (CWs) are receiving a renewed attention as a viable phytotechnology for treating agricultural wastewaters and for the removal of more specific pollutants, in particular recalcitrant ones. In this work, the performance of CW mesocosms using light expanded clay aggregates (LECA) as the bed's substrate and planted with Phragmites australis was investigated for treatment of olive mill wastewater (OMW), swine wastewater (SW) contaminated with oxytetracycline and water contaminated with herbicide MCPA (2-methyl-4-chlorophenoxyacetic acid). Both wastewaters (OMW and SW) initially presented high organic matter content and total suspended solids which were removed by the system with efficiencies higher than 80%. Removal of polyphenols in OMW and nitrogen compounds in SW also showed similar or higher efficiencies in comparison with other treatment systems reported in the literature. The antibiotic oxytetracycline was completely removed from SW within the assay period in unplanted LECA beds, but planted beds allowed a significantly faster removal. In regard to water contaminated with MCPA, the results showed that LECA has a large sorption capacity for this herbicide (removal efficiencies of 56-97%). In general, considerably higher pollutant removal efficiencies were obtained when plants were used (up to 28% higher). The results obtained are indicative that CWs with LECA as substrate may be an adequate option for agricultural wastewater treatment., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Annulatascus nilensis sp. nov., from freshwater habitats in Egypt, is described, illustrated and compared to other species in the genus. Phylogenetic analyses of its LSU rDNA sequence with similar fungi placed the new species in the genus Annulatascus (Annulatascaceae, Sordariomycetidae incertae sedis). Annulatascus nilensis is characterized by immersed ascomata with an ascomatal neck oriented horizontally to the substrate surface, asci with a long, narrow stalk and massive bipartite apical ring, and 5-11-septate, hyaline ascospores surrounded by a large irregular, granular sheath that is not seen in water.

Phragmites rhizome cuttings, and plantlets raised from seed, were exposed to the phytotoxins acetic acid or dissolved sulphide in unstirred solution cultures to determine whether die-back symptoms found in field-grown plants, and attributed to phytotoxin damage, could be induced. Many of the die-back symptoms associated with field sites, namely stunted adventitious roots and laterals, bud death, callus blockages of the gas-pathways, and vascular blockages, were all reproduced, and were particularly acute at the higher concentrations of the phytotoxins: acetic acid (1.67 mm), sulphide (1.4 mm). The results accord with the hypothesis that phytotoxins may play a critical role in Phragmites australis die-back.

The development of lakeside fringes of Phragmites reeds can be affected by high water levels, leading in extreme cases to die-back. A model is presented that allows estimation of the proportions of the damage. The model-formulated for 1 year and one Phragmites stalk-is based on the growth curve of the stalk, the altitude of the growth site, and the water level curve for the year. Applied to a reed stand over a series of years, the model is based upon the frequency distribution of the critical stalk length and the chance that the water level will be below a given value, each parameter being time dependent. Three case studies from Lake Constance-Untersee provide an example of the significance of episodic high water levels. Hence, aestival high water levels are expected to be one of the main factors controlling the lakeside frontline of the reedbelt. The model can be used in waterworks engineering, where reed plantations are to be established on the shores of lakes and reservoirs with strongly fluctuating water levels.