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As reflectance measured via remote sensing is connected to plant light use and morpho-structural features, it can be used to derive spectral proxies of functional traits, or spectro-functional traits. Focusing on disentangling intraspecific trait variability in nature, we evaluated the links between haplotype and spectro-functional traits inPhragmites australispopulations.Haplotypes sequencing and multi-seasonal satellite data were used to evaluate the temporal dynamics of spectro-functional traits for reed stands sampled from seven wetlands in Central Italy, investigating meteo-climatic drivers, the differences across ecological statuses, sites, and haplotypes, and quantifying intraspecific variability due to haplotype or phenotypic plasticity.Five haplotypes were identified, including an unedited one, which explained a substantial portion of intraspecific variability in canopy traits, differing for aquatic and terrestrial stands. We found that meteo-climatic factors impact on aquatic reeds traits (not over terrestrial ones) and a dualism between most and less common haplotypes, pointing to different evolutionary strategies. Dynamics in reed canopy traits were linked to ecological status, site and haplotype, with signs of haplotype-variable effects of dieback on aquatic stands.Evaluating the spectro-functional variability over reed haplotypes may provide a straightforward approach for monitoring the genotype-phenotype relations across scales and assessing their ecological drivers.

Uncrewed aircraft systems (UASs) are a popular tool when surveilling for invasive alien plants due to their high spatial and temporal resolution. This study investigated the efficacy of a UAS equipped with a three-band (i.e., red, green, blue; RGB) sensor to identify invasive Phragmites australis in multiple Minnesota wetlands using object-based image analysis (OBIA) and machine learning (ML) algorithms: artificial neural network (ANN), random forest (RF), and support vector machine (SVM). The addition of a post-ML classification OBIA workflow was tested to determine if ML classifications can be improved using OBIA techniques. Results from each ML algorithm were compared across study sites both with and without the post-ML OBIA workflow. ANN was identified as the best classifier when not incorporating a post-ML OBIA workflow with a classification accuracy of 88%. Each of the three ML algorithms achieved a classification accuracy of 91% when incorporating the post-ML OBIA workflow. Results from this study suggest that a post-ML OBIA workflow can increase the ability of ML algorithms to accurately identify invasive Phragmites australis and should be used when possible. Additionally, the decision of which ML algorithm to use for Phragmites mapping becomes less critical with the addition of a post-ML OBIA workflow.

Eutrophication and reduced grazing have led to an expansion of the common reed (Phragmites australis) in archipelago areas in the Baltic Sea, while at the same time the composition of submerged vegetation has changed. Although reed is important as nursery habitat for many fish species, extensive emergent vegetation may reduce biodiversity and abundance of predatory fish. Pike (Esox lucius) is a predatory fish whose larvae and young-of-the-year find both food and shelter in reed but use different micro-habitats during different life-stages. Here we investigate the influence of reed and submerged vegetation on abundance and body size of adult pike during the spawning season. We predicted that coastal bays with extensive but heterogeneous reed beds with higher cover of submerged vegetation would have more and larger pike than bays with smaller, homogenous reed belts or with less submerged vegetation. To test these predictions, we estimated abundance and size-structure of adult pike from catches in angling fishing among 22 bays in the Stockholm archipelago at the Swedish Baltic Sea coast. Our analyses show that catches of adult pike were positively associated with both extensive reed beds and cover of rooted submerged vegetation. However, pike size was not correlated with any vegetation variable, but instead increased with wave exposure and bay area. Our study suggests that reed beds and submerged vegetation are important for adult pike during the spawning season, and even the most extensive reed beds had no evident negative effect on pike populations. We could not see any clear relationship between emergent reed habitat and cover of submerged vegetation among the studied bays, and conclude that to maintain pike population during the spawning season it is important that coastal bays have sufficient amounts of both reed beds and rooted submerged vegetation.

Soil salinization is one of the most severe environmental problems restricting biodiversity maintenance and ecosystem functioning in a coastal wetland. Recent studies have well documented how salinization affects soil microbial communities along vegetation succession of coastal wetlands. However, the salinity effect is rarely assessed in the context of plant intraspecific variation. Here, we analyzed the soil bacterial and fungal communities of Phragmites australis wetland using amplicon high-throughput sequencing at a fine scale (within 1000 m) in the Yellow River Delta. Our results revealed that microbial diversity is significantly correlated to soil salinity (assessed as electrical conductivity, EC) but not to soil nutrients (N and P content) or plant intraspecific traits (leaf length, shoot height, and neutral genetic variation). Specifically, the microbial diversity tended to decrease with increased EC, and the bacterial community was more sensitive to EC change than the fungal community. The dominant bacterial phyla were Proteobacteria, Actinobacteria, and Chloroflexi, and the dominant fungal phyla were Ascomycota, Basidiomycota, and Mortierellomycota. The relative abundance of Actinobacteria was significantly negatively correlated to EC, while Proteobacteria were positively correlated to EC. In high salinity (> 1 mS/cm), the role of the stochastic processes became more important in community assembly according to habitat niche breadth estimation, neutral community model, C-score metric, and normalized stochasticity ratio. Additional common garden and microcosm experiments provided evidence that the genotype effect of P. australis on soil microbiome might only occur between lineages from different regions but not from the same region like the Yellow River Delta. Our findings provide new insights into soil microbial community assembly processes with the intraspecific variation of host plants in the wetland ecosystem and offer a scientific reference for salinity mitigation and vegetation management of coastal wetlands under future global changes.

Constructed wetlands (CWs) have been demonstrated as a cost-effective alternative to chemical treatment systems for mine waters, with the microbial communities attributed to promoting carbonation and aiding pH neutralization. However, few data are available for the long-term use of CWs treating alkaline leachates nor the activity of microbes within them. To investigate the feasibility of CW to buffer alkaline pH, a pilot-scale wetland was implemented in 2015 to treat alkaline bauxite residue leachate. After 5.5 years, samples of supernatant water and sediment were taken at 0.5 m increments along the 11 m long wetland. Waters were analysed for pH, EC and metal(loid) content, while sediment was subjected to physico-chemical assessment and element fractionation. Microbial biomass and community were assessed by phospholipid fatty acid analysis (PLFA) and functionality by the Rapid Automated Bacterial Impedance Technique (RABIT). Evidence presented demonstrates that the CW operating for 66 months effectively treats bauxite residue leachate, with reduced influent pH from 11.5 to 7.8. Trace element analysis revealed effective reduction in Al (94.9 %), As (86.7 %) and V (57.6 %) with substrate analysis revealing a frontloading of elevated pH and trace element content in the first 5 m of the wetland. Sediment Al, As and V were present mostly (>94 % of total) in recalcitrant forms. Sediment Na was mostly soluble (48–62 %), but soils were not sodic (ESP < 15 %). Investigations into the microbial community revealed greatest biomass was in the first 5 m of the wetland, where pH, EC and metal contents were greatest. Microbial respiration using endemic Phragmites australis as a substrate demonstrates an ability to cycle recalcitrant carbon sources within a CW system. These novel microbial findings highlight the need for further investigation into the microbial communities in alkaline CWs.

This dataset contains the results of chromium and nutrients (N and PO4-P) removal in floating treatment wetland microcosm experiment with two cosmopolitan species of parennials: Phragmites australis and Iris pseudacorus.

Growing productive wetland species on rewetted peatland (paludiculture) is a promising solution to offset carbon loss from drained peatlands. The inlet of nitrogen (N) rich surface water, a proposed method to improve productivity of vegetation, may affect methane (CH4) emissions. This study aims to compare initial CH4 emissions from newly rewetted peat with different types of vegetation and N loading simulating diffuse N inlet. Diffusive CH4 emissions were measured in peat mesocosms during one growing season. Peat cores were either planted with Typha latifolia or Phragmites australis or they were left bare. Mesocosms received 0, 50, 150 or 450 kg ha-1 year-1 N. Plants affected CH4 emissions from rewetted peat soil, leading to stable fluxes over time of 133 mg m-2 day-1 CH4 at 20 °C. Biomass harvesting lead to a 153% increase of CH4 emissions. With increasing N load, CH4 emissions from mesocosms with Typha and Phragmites decreased up to a load of 150 kg ha-1 N, but this was only significant for the Phragmites treatment. Emissions of unvegetated mesocosms increased with increasing N load but not significantly. In conclusion, our mesocosm study suggests that vegetation can reduce or prevent an increase in CH4 emissions from rewetted peatlands compared to only rewetting, possibly due to an increased oxygenation of the sediments by macrophyte roots preventing excessive CH4 formation, while added N does not provoke great changes in emissions at N concentrations up to 150 kg ha-1.

Plant residue decomposition can significantly affect the water environment of wetland ecosystems. However, little is known about the trajectory and the key drivers of the different initial mass of residue (IMR) that regulate water quality. Here, we conducted a study of 210 days with an in situ experiment to examine the impact of the change in IMR and the key decomposition parameters of Phragmites australis on the water quality in the growing season of 2019 in Baiyangdian wetland in North China. Five IMR of the Phragmites were applied, ranging from 0 to 1000 g with 250 g increments. The chemical oxygen demand (COD_W), total organic carbon (TOC_W), total nitrogen (TN_W) and total phosphorus (TP_W) of the water, and the total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), cellulose, lignin, decomposition rate (k) and the remaining mass of the Phragmites in the bag (RM) were monitored. Our results showed that the IMR of the Phragmites only marginally influenced the decomposition of itself and; the variations in the level of the water indicators were ranked as TN > TP > COD > TOC and; the impacts of IMR were longer on TOC and COD than on TP and TN and; the change in water quality was significantly influenced by the Phragmites decomposition and highly correlated with the change in TOC, cellulose and k of decomposing Phragmites residue. These results indicated that the impact of 250 g of IMR on the water was negligible after 120 days, suggesting that the optimal harvest rate of the Phragmites should be above 75% in the Baiyangdian wetland, despite the strong impact at the beginning and; the impact of change in IMR on water quality can be explained by the change in the decomposition parameters of the decomposing Phragmites residue, where such a decomposition-based explanation might be a promising tool to link wetland plant management and water quality.

Purpose: The encapsulation of toxic metal(loid)s in phytoliths represents a new area of research. The accumulation of metal(loid)s in phytoliths can alter the fate and toxicity of soil metal(loid). Pteris multifida is a well-known As hyperaccumulator which also harbors phytoliths. However, As accumulation in phytoliths has not yet been studied. Soil water content is considered the main factor influencing phytolith accumulation and also remains unexplored with respect to As accumulation in phytoliths. In this study, As concentration in the phytoliths of P. multifida was compared with that in Phragmites australis phytoliths as a function of the soil water content. Methods: P. multifida and P. australis were grown under different soil water contents. The As concentration in phytoliths, roots, and shoots of plants was then determined.Results: The range of As concentration in the phytoliths of P. multifida was 414.70 - 1610.74 mg kg-1, and that for P. australis phytoliths was 41.67 - 126.54 mg kg-1. In P. multifida, higher soil water content increased As accumulation in phytoliths but did not affect phytolith content in the plant. In P. australis, the higher soil water content increased phytolith content in the plant but decreased As concentration in phytoliths. Conclusion: This study suggests that P. multifida has higher As content in phytoliths than P. australis, and this accumulation can be affected by soil water content. The current findings provide insight into the accumulation of As in phytoliths and provide a theoretical basis for our understanding on the fate of As in the environment.

In treatment wetlands (TWs), solids accumulation can result in hydraulic malfunction, reducing the operation life, and it could enhance biological activity by favoring biofilm development. It is still unknown whether the solids accumulation can affect greenhouse gas (GHG) emissions. This study aims to evaluate the solid concentration along a horizontal flow (HF) TW, and its role in GHG emissions, hydraulics, treatment performance, and vegetation development (Phragmites australis (Cav.) Trin. ex Steud.). The study was carried out in an eight-year-old full-scale HF-TW located in the Mediterranean region (Sicily, Italy). To collect data inside the HF unit, nine observation points (besides the inlet and the outlet) along three 8.5-m-long transects (T1, T2, and T3) were identified. The first transect (close to the inlet zone) showed a hydraulic conductivity (Ks) reduction approximately one order of magnitude higher than the other two. Results highlighted that GHG emissions increased during the summer, when the temperature and solar radiation were higher than in the rest of the year, matching the macrophyte growth rate. Theoretical methane (CH4) emissions followed the trend of volatile solids (VS), which was around 3.5 and 4 times in T1 to T2 and T3. Pore clogging affected carbon dioxide (CO2) emissions, which decreased from T1 to T3, with maximum monthly values in T1 (21.4 g CO2·m−2·d−1) being approximately double with respect to T2 (12.6 g CO2·m−2·d−1) and T3 (10.7 g CO2·m−2·d−1) observed in July. The same trend for chemical oxygen demand (COD) removal efficiency, decreasing from T1 to T3, was observed. Notwithstanding this behavior, the final effluent quality was very satisfactory, with an average value of COD removal efficiency above 90%.

Constructed wetlands (CWs) are effective wastewater treatment systems, relying on plant and substrate uptake and microbial depletion to remove pollutants. It has been reported that melatonin can promote plant growth and change the structure of microbial communities. The effects of melatonin on stress tolerance of plants have been extensively studied, while the effects of melatonin on the efficiency of wastewater treatment in constructed wetlands are rarely known. In the current study, 1 mM melatonin was added to the constructed wetland systems to determine physiological characteristics of Phragmites australis, microbial enzyme activity, and microbial community structure of CWs. Under melatonin treatment, the An and gs of Phragmites australis plants were significantly improved compared with the control. In addition, the contents of phosphate and total anion in the xylem sap of Phragmites australis significantly increased. However, the concentration of total phosphorus in the effluent did change significantly. Melatonin treatment improved the dehydrogenase activity and significantly improved the removal efficiency of NH4+-N in CWs. Furthermore, melatonin reduced the richness of the microbial community in CWs, while it increased the diversity of bacterial community and altered microbial composition. FARPROTAX analysis showed that melatonin increased the abundance of bacteria involved in nitrogen fixation and ureolysis, which may be related to the improvement of plant photosynthetic performance and improved rhizosphere oxygen environment. These results suggested that melatonin may affect plant performance and microbial composition and functions to improve the purification effect of constructed wetland.

Phragmites australis is highly adaptable with high competitive ability and is widely distributed in the coastal wetland of the Yellow River Delta. However, allelopathic effects of P. australis on the growth of neighboring plants, such as Suaeda salsa, are poorly understood. In this study, germination responses of S. salsa seeds collected from two different habitats (intertidal zone and inland brackish wetland) to the extracts from different part of P. australis were compared. Potential allelopathic effects on germination percentage, germination rate, radicle length, and seedling biomass were analyzed. The germination of S. salsa was effectively inhibited by P. australis extract. Extract organ, extract concentration, and salt concentration showed different effects, the inhibitory rates were highest with belowground extract of P. australis between the four different parts. Germination percentage and germination rate were significantly decreased by the interactive effect of salt stress and extract concentration in S. salsa from a brackish wetland but not in S. salsa from the intertidal zone. The impact of different extracts of P. australis on radicle length and seedling biomass of S. salsa showed significant but inconsistent variation. The response index results showed that the higher concentration of extract solution (50 g·L−1) of P. australis had stronger inhibitory effect on the seed germination and seedling growth of S. salsa while the belowground extract had the strongest negative effect. Our results indicated that allelopathy is an important ecological adaptation mechanism for P. australis to maintain a high interspecific competitive advantage in the species’ natural habitat.

The decomposition process in wetlands is affected by various factors, among which hydrology and litter quality are very important. We studied the decomposition rate of Phragmites australis upper and lower leaf litter from the lake and the riparian sites at the intermittent Lake Cerknica (Slovenia), exposed to flooded and dry conditions. Xray fluorescence spectrometry revealed that leaf litter element composition was related to soil element composition. Fresh leaves also differed according to their age, especially regarding leaf silicon, which ranged from 2.8% to 6.1% dry matter, and leaf phosphorus, which ranged from 0.12% to 0.17% dry matter for the different leaf groups. According to factorial ANOVA, leaf litter decomposition rate was significantly affected by sampling site, exposure location, and leaf age (p ≤ 0.01). Decomposition rate was significantly lower at the dry location compared to the flooded location, and was not related to leaf silicon content. However, leaf sulphur, chlorine, and calcium contents had a significant positive impact on leaf litter decomposition rate at both the dry and the flooded locations. Leaf phosphorus significantly positively affected leaf litter decomposition rate only at the dry location.

Modern urban societies generate tremendous amounts of hazardous wastes, including toxic organics and metals. Toxic metals harm plants and pose a risk to human health; examples of them are copper (Cu), zinc (Zn), palladium (Pb), and cadmium (Cd). Wetland plants are excellent for the ecological restoration of toxic metal-affected environments. Phragmites australis (common reed) belongs to the family Poaceae and is a broadly distributed wetland grass that is native to Bahrain, Europe, and America. P. australis shows a high content of chlorophyll. This study aimed to assess percentages of water, chlorophyll, and toxic metal content using acetone extraction; the calculation of the concentrations was performed according to the equations proposed by Lichtenthaler and the percentage of water content was calculated. After the metal exposure, the reed plants were digested, and their total mineral analysis was accomplished by atomic absorption spectroscopy; statistical analysis was conducted by Statistical Package for the Social Sciences (SPSS) version 21. The results revealed that the immature stage showed the highest chlorophyll a (mean 1641.5 (µg/g)) carotenoids (mean 359.75 (µg/g)) and total chlorophyll (mean 2183.93 (µg/g)), and the mature flowering stem had the highest chlorophyll b (mean 676.45 (µg/g)). The mature flowering stem stage showed the highest Pb (mg/L) and Cd (mg/L) values; on the other hand, Cu was the highest in the fully elongated non-flowering stage (0.108 mg/L), and the highest Zn content was found in the immature stage (mean 2.083). Owing to its growth in contaminated environments, P. australis can be considered a potential source of phytonutrients; higher concentrations were mostly available in the immature and mature flowering stages, with a favorable immature stage. The use of such marginal wetland plants may be very useful in reducing the pollution burden of urban built environments. These plants offer a green and sustainable solution for the disposal of waste from urban areas. Hence, further planning and execution of such a green solution are pivotal for creating environmental sustainability.

Mapping 3D vegetation structure in wetlands is important for conservation and monitoring. Openly accessible country‐wide Airborne Laser Scanning (ALS) data—using light detection and ranging (lidar) technology—are increasingly becoming available and allow us to quantify 3D vegetation structures at fine resolution and across broad spatial extents. Here, we develop a new, open‐source workflow for classifying wetland‐related land cover types and habitats using fine‐scale lidar metrics derived from country‐wide ALS data. We developed a case study in the Netherlands with a workflow consisting of four routines: (1) pre‐processing of ALS data, (2) calculation of lidar metrics (i.e. 31 features representing cover, 3D shape, vertical variability, horizontal variability and height of vegetation as well as microtopography), (3) assessing feature importance of lidar metrics for classifying wetland habitats, and (4) applying a Random Forest algorithm for mapping and prediction. We used an expert‐based vegetation map for annotation and generated 100, 500 and 1000 annotation points for each class. Using a three‐level hierarchical approach, we differentiated at level 1 planar surfaces (e.g. roads and agricultural fields) from wetland vegetation with 82% mean overall accuracy, using predominantly height and horizontal variability metrics. At level 2, we classified wetland vegetation into four land cover types (forest, grassland, reedbeds, shrubs) with 71% mean overall accuracy, using lidar metrics related to vegetation height and horizontal and vertical variability. At level 3, we differentiated two types of land reed as well as water reed with 78% mean overall accuracy, using predominantly vertical variability metrics. Our results demonstrate that lidar metrics (related to vegetation height, cover, vertical and horizontal variability) derived from country‐wide ALS data can differentiate land cover types and habitats within wetlands at high resolution. Given appropriate annotation data, our workflow can be up‐scaled to a country‐wide extent to allow the comprehensive mapping and monitoring of wetlands at national scales.

Biochar produced by pyrolysis of biomass under oxygen‐limited conditions has recently attracted increasing attention. To investigate the effects of feedstock and pyrolysis temperature on biochar characteristics, Phragmites australis straw and Spartina alterniflora straw were used to produce biochars at different temperatures from 300 to 500°C with an increment of 50°C. The biochars were characterized by their yields, ash contents, elemental compositions (i.e., carbon [C], hydrogen [H], oxygen [O], and nitrogen [N]), functional groups, dissolved organic carbon (DOC) contents, carbon sequestration potential, higher heating values (HHVs), and production costs. The results illustrated that pyrolysis temperature negatively affected biochar yields, H and O contents. In contrast, biochar produced at high temperature showed high ash contents, C contents, HHVs, and stronger aromaticity with low H/C and O/C ratios. In addition, S. alterniflora‐derived biochar (SB) contained higher ash content but lower C/H/N/O contents and HHVs than P. australis‐derived biochar (PB; p

The extensive global use of bisphenols (bisphenol A (BPA) and its analogs) is of serious concern to human health and aquatic ecosystems. Aquatic plants and rhizosphere microorganisms can largely affect the environmental fate of bisphenols. In this study, the association between common reed, which is distributed widely in the aquatic environment, and microorganisms existing in the surrounding area of its roots was studied to illustrate its capabilities and possible mechanisms for the removal of five different bisphenols (BPA, bisphenol F, bisphenol P, bisphenol S, and 4,4ʹ-thiodiphenol). Different experimental systems were prepared in the presence and absence of sterile common reeds and aquatic microorganisms. The effects of common reed and microorganisms on the removal of bisphenols differed across compounds. However, the removal of all the bisphenols tested was clearly accelerated in the co-presence of common reed and microorganisms, which indicated the importance of aquatic plant-microorganism association in enhancing bisphenol removal. The results of this study further revealed the major contribution of the distinct mechanism of removal of each bisphenol by the association between common reed and microorganisms.

The city of Zhangye (Gansu Region, China) has been subjected to several changes related to the development of new profitable human activities. Unfortunately, this growth has led to a general decrease in water quality due to the release of several toxic wastes and pollutants (e.g., heavy metals) into the Heihe River. In order to assess the environmental exposure and the potential threat to human health, microbiological diversity for the monitoring of water pollution by biotic and abiotic impact factors was investigated. In particular, we analysed samples collected on different sites using 454 pyrotag sequencing of the 16S ribosomal genes. Then, we focused on alpha-diversity indices to test the hypothesis that communities featuring lower diversity show higher resistance to the disturbance events. The findings report that a wide range of environmental factors such as pH, nutrients and chemicals (heavy metals (HMs)), affected microbial diversity by stimulating mutualistic relationships among bacteria. Furthermore, a selection in bacterial taxa related to the different concentrations of polluting compounds was highlighted. Supporting the hypothesis, our investigation highlights the importance of microbial communities as sentinels for ecological status diagnosis.

Recent advances in image classification of fine spatial resolution imagery from unoccupied aircraft systems (UASs) have allowed for mapping vegetation based on both multispectral reflectance and fine textural details. Convolutional neural network (CNN)-based models can take advantage of the spatial detail present in UAS imagery by implicitly learning shapes and textures associated with classes to produce highly accurate maps. However, the spatial resolution of UAS data is infrequently examined in CNN classification, and there are important tradeoffs between spatial resolution and classification accuracy. To improve the understanding of the relationship between spatial resolution and classification accuracy for a CNN-based model, we captured 7.6 cm imagery with a UAS in a wetland environment containing graminoid (grass-like) plant species and simulated a range of spatial resolutions up to 76.0 cm. We evaluated two methods for the simulation of coarser spatial resolution imagery, averaging before and after orthomosaic stitching, and then trained and applied a U-Net CNN model for each resolution and method. We found untuned overall accuracies exceeding 70% at the finest spatial resolutions, but classification accuracy decreased as spatial resolution coarsened, particularly beyond a 22.8 cm resolution. Coarsening the spatial resolution from 7.6 cm to 22.8 cm could permit a ninefold increase in survey area, with only a moderate reduction in classification accuracy. This study provides insight into the impact of the spatial resolution on deep learning semantic segmentation performance and information that can potentially be useful for optimizing precise UAS-based mapping projects.

Peatlands are a diverse type of wetland ecosystem, characterized by high levels of soil organic matter, that provide a wide array of ecosystem services including water storage and filtration, carbon sequestration, and unique habitats. Draining peatlands degrades their resilience to future disturbances, notably including high intensity, soil-consuming fires. Peat soil fires are unique in that they can smolder vertically through the soil column, with consequences ranging from large carbon emissions to altered hydrology and dramatic shifts in vegetation communities. In this work we had two complementary objectives to understand both the drivers and impacts of smoldering fires at the Great Dismal Swamp (VA and NC, USA). First, we developed and verified a new method to model peat burn depths with readily available water level and peat hydraulic property data. Our findings suggest that drainage weakens both short- and long-term controls on peat burn depths by reducing soil moisture and by decreasing peat water holding capacity. To address the impacts of smoldering fires, we quantified the abundance of the noxious Phragmites australis in a large fire scar and the extent to which altered hydrology influenced its occurrence. We did so by leveraging satellite imagery, random forest models, LiDAR data, and water table observations. Our results suggest that P. australis is aided by a hydrologic regime generated, in part, from the combined effects of drainage and deep smoldering fires. Our conclusions from these two studies contribute to the scientific understanding of smoldering peat fires and can inform management efforts. Master of Science Peatlands are a diverse type of wetland ecosystem that have characteristically thick levels of organic-rich soil, known as peat. Peatlands are home to a variety of unique plants and animals, store large amounts of carbon, and provide water storage functions. Peatlands were historically drained to enable development and conversion to other land usages, which had many unintended consequences like increasing their risk to wildfires that consume soil organic matter. An intense peat fire can smolder down through the peat, with impacts ranging from large releases of carbon to changes in water levels and vegetation communities. In this work we had two objectives aimed at understanding the drivers and impacts of smoldering peat fires in the Great Dismal Swamp (GDS) (VA and NC, USA). First, we developed and verified a new method of modeling how deep peat fires burn by using readily available water level and soil property data. Our findings suggest that drainage weakens both the short- and long-term controls on peat fire burn depths by reducing soil moisture and by limiting the ability of peats to hold water. We also studied how water levels in a post-peat consuming fire environment influence the amount of the weedy Phragmites australis. We did so by using satellite imagery, elevation data, and water table observations. Results from this investigation suggest that the combined effects of drainage and deep smoldering fires help to create ideal conditions for P. australis invasion and establishment. Our findings from these two studies add to the scientific understanding of smoldering peat fires and may inform land management decisions.

This research was carried out in the vicinity of Kant Cement Plant located in Issyk-Ata district, Cuy region of Kyrgyzstan. Kant Cement Plant produces approximately 600,000-700,000 tonnes of cement per year. Because of the cement production, a large amount of cement dust release containing some heavy metals and other toxic substances occurs in the nearby environment. The aim of our research was to investigate the negative effects of the cement dust spreading around on living organisms. In this research, the reed plant (Phragmites australis L.) was used as a study material to determine the rate pollution observed nearby Kant via the detection of heavy metal and nutrient element contents (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn) of the collected plant and co-located soil samples using ICP-OES. Also, the total chlorophyll contents in the leaves of the plant samples was measured using CCM-200 plus (Opti-Sciences). The lowest and highest heavy metal and mineral element contents of the plant samples (in mg kg1 ) were found to be as: 119.30 (in stems) and 3908.11 (in roots) for Al in stations 9 and 6; 12.52 (in stems) and 47.88 (in unwashed leaves) for B in control (1) and station 6; 3432.38 (in stems) and 10120.64 (in roots) for Ca in control (1) and station 6; 125.95 (in washed leaves) and 87.38 (in stems) for Cd in control (1) and station 6; 6.74 (in stems) and 24.56 (in roots) for Cr in control (1) and station 6; 3.92 (in stems) and 28.13 (in unwashed leaves) for Cu in control (1) and station 6; 303.82 (in stems) and 1100.86 (in unwashed leaves) for Fe in control (1) and station 6; 5334.55 (in stems) and 23789.68 (in unwashed leaves) for K in control (1) and station 6; 692.44 (in stems) and 3352.71 (in unwashed leaves) for Mg in control (1) and station 6; 33.94 (in stems) and 391.22 (in roots) for Mn in control (1) and station 6; 162.30 (in stems) and 709.03 (in unwashed leaves) for Na in control (1) and station 6; 3.5 (in stems) and 19.61 (in roots) for Ni in control (1) and station 6; 2.25 (in stems) and 20.41 (in unwashed leaves) for Pb in control (1) and station 6; and 35.94 (in stems) and 147.65 (in roots) for Zn in control (1) and station 6, respectively. The lowest and highest heavy metal and mineral element contents of the soil samples (in mg kg-1 ) were found to be as: 30034.07 and 38334.45 for Al in stations 9 and 6; 39.61 and 80.32 for B in control (1) and station 6; 11832.33 and 23922.33 for Ca in control (1) and station 6; 165.38 and 1457.8 for Cd in control (1) and station 6; 20.79 and 42.29 for Cr in control (1) and station 6; 14.8 and 45.84 for Cu in control (1) and station 6; 17390.18 and 35158.99 for Fe in control (1) and station 6; 10230.83 and 20684.6 for K in control (1) and station 6; 4356.34 and 8807.68 for Mg in control (1) and station 6; 598.38 and 1210.04 for Mn in control (1) and station 6; 1163.76 and 2353.09 for Na in control (1) and station 6; 27.68 and 56.16 for Ni in control (1) and station 6; 18.47 and 77.94 for Pb in control (1) and station 6; and 136.29 and 275.73 for Zn in control (1) and station 6, respectively. When the results obtained from our work were compared with the controls, it showed that the Cement plant in Kant cause pollution in nearby environment by the way of releasing heavy metals including Cd, Cr, Pb and Ni (partially). Kyrgyzstan is a country recently showing an increasing growth trend. As a result of high rate of urbanization following of economic and industrial development, Kyrgyzstan encounters with the problems related with pollution. From our work, the recommendation to the local authorities to take necessary precautions before the pollution reaching dangerous levels. By our work, the recommendation would be to the local authorities to take necessary precautions before the pollution reaching dangerous levels. Keywords: Phragmites australis, Biomonitoring, Heavy Metal Pollution, Cement Dust, Kant

Purpose Paludiculture (crop cultivation in wet peatlands) can prevent carbon and nutrient losses while enabling biomass production. As vegetation in rewetted peatlands is often nitrogen (N) limited, input of N-rich water may promote biomass production and nutrient removal. However, it is unclear how N loading and soil characteristics affect biomass yield, nutrient dynamics, and ecosystem service provisioning in paludiculture. Methods We studied the influence of N loading (0, 50, 150, and 450 kg N ha−1 yr−1) on biomass production and nutrient sequestration of Typha latifolia (broadleaf cattail) and Phragmites australis (common reed) in mesocosms containing rewetted agricultural peat soil (intensively managed, near-neutral (IN)). To assess the interaction with soil characteristics T. latifolia was also grown on an extensively managed, acid (EA) peat soil. Results N loading stimulated biomass production and nutrient uptake of both T. latifolia and P. australis, with T. latifolia showing the most pronounced response. Biomass yield of T. latifolia was higher on IN soil than on EA soil due to the higher pH, despite lower nutrient availability. N was largely taken up by the vegetation, whereas bare soils showed N accumulation in pore and surface water, and 80% loss through denitrification. Soil phosphorus was efficiently taken up by T. latifolia, especially at high N loads. Conclusion N loading in paludiculture with T. latifolia and P. australis boosts biomass production while kick-starting peatland ecosystem services including nutrient removal. Nutrient availability and pH appear to be decisive soil characteristics when it comes to crop selection.

The dynamics of overgrowing of spawning grounds in the southern area of Peipsi-Pihkva Lake complex is considered, based on 28 years of observations from Anokhovo Bay. The history of the study of the water area is analyzed in detail, the species and syntaxonomic composition of plant associations in the littoral areas of the bay is described, and the dominant species are established. Over the entire observation period, the total number of macrophyte species increased by almost 2.5 times, and the number of plant associations increased approximately twofold. The area of the bay overgrown with macrophytes increased by 9.5%, with a simultaneous increase in the overgrowth density. The dominant species are common reed Phragmites australis, lakeshore bulrush Schoenoplectus lacustris, and yellow water-lily Nuphar lutea.

Polyploidization and hybridization are very common in natural plant species, and mixed-ploidy species provide a unique opportunity to study the effects of evolutionary history, local abundance, and ploidy level on the direction and extent of introgression between intraspecific lineages. First, we delimited two morphologically cryptic lineages of Phragmites australis Trin. ex Steud. in temperate China using 11 nuclear microsatellites and two chloroplast DNA fragments with 225 samples from China as well as 11 samples from Oceania and Europe. Our evidence supported that haplotype O and haplotype P were two relatively independent lineages with low and high ploidy levels, respectively; haplotype M might be ancient and could have undergone a complex evolutionary history. Then we examined the lineage divergence and compared the introgression patterns between two major lineages along geographical and abundance gradients with a large number of samples (n = 1067) collected from China. The sympatric coexistence of two lineages in north and northeast China implies an ongoing or potential introgression between them. Cline analysis showed that the level of genetic admixture were significantly correlated with longitude rather than latitude. Our results also suggested that ploidy level could deeply influence the introgression asymmetry, and the effect of the current local abundance on introgression might be covered by the past coexistence time driven by phylogeographic history. Our study draws a baseline for future research on the ecological and evolutionary consequences of migration and introgression of Chinese P. australis under global change.

Distribution and level of 16 individual and total polycyclic aromatic hydrocarbons (∑PAHs) were assessed in soils, roots and above-ground tissues of reed (Phragmites australis) on monitoring plots in the city of Kamensk-Shakhtinskyi (Southern Russia, Rostov Region). The total concentration of the 16 PAHs in soil samples ranged between 499.0 to 7177.9 µg kg-1. Samples from the plot no. 4 had the highest PAHs concentrations of 7177.9 µg kg-1. The mean concentration of ∑16PAHs in plot no. 3 was noticeably higher than those in other monitoring sites for both root (363.0 µg kg-1) and above-ground tissues (239.8 µg kg-1). The distribution of PAHs ring size was in the order of 5-6˃4˃3˃2 in soil samples and HMW PAHs fractions represent 57.3% of the total PAHs. The concentrations of 3-4 ring PAHs were higher than HMW PAHs with 5–6 aromatic rings in all P. australis tissues. Diagnostic ratios of PAHs indicated that anthropogenic activities were probably major sources of PAHs. Accordingly, the maximum accumulation was found for phenanthrene among the 16 priority PAHs in the most of the soil and plants samples. More PAHs were accumulated in roots, as reflected by its higher mean concentration of PAHs in each plot. In addition, the BCF and TF values of LMW PAHs with 2- and 3-rings were higher than those of HMW PAHs. Taken together, our results indicated that there were an intensive accumulation of PAHs in the zone of industrial sewage tanks and sludge reservoirs as well as an obvious translocations of PAHs from the polluted soils to plant tissues, therefore, more attention is required to be paid to the PAH contamination in this area.

Widespread plant species generally have high intraspecific variation in functional traits, which is reflected in their great variety of phenotypes. This variety can result from both genetic differences due to local adaptation and phenotypic plasticity. With high intraspecific variation and nearly global distribution, the common reed Phragmites australis is a suitable model species for studying the underlying mechanisms of intraspecific trait variation. In this study, 71 genotypes of P. australis from seven phylogeographic groups were transplanted into two replicate common gardens located in very different climates: northern Europe and mid-east Asia. We measured seven functional traits of all these genotypes over the growing season, including shoot height, maximum biomass per shoot, shoot density, node number per stem, leaf life span, flowering occurrence and flowering date. Our aim was to assess the relative effects of genetic (phylogeographic origin) and environmental (common garden) status, and interactions between them, on intraspecific variation in functional traits of P. australis. We found common garden having the strongest influence on most functional traits studied. All traits except flowering occurrence varied significantly across gardens, revealing the important role of phenotypic plasticity on trait variation in P. australis. We also found significant differences in trait variation among the different phylogeographic groups of P. australis and, thus, evidence for genetically determined intraspecific variation in the morphological and life-history traits addressed in this study. All functional traits showed significant (p ≤ 0.0054), albeit minor to moderately explained (R2 ≤ 0.57), latitudinal patterns in both gardens. Covariation of multiple traits was similar in the two gardens. Phenotypic plasticity was trait- specific, and the plasticity of shoot height and maximum biomass per shoot increased towards higher latitude of genotypic origin. Our results indicate that the latitude of origin affects the evolution of functional traits, as well as their phenotypic plasticity. Since phenotypic plasticity is a crucial mechanism for acclimation and evolution, our findings support the role of gene-based adaptive phenotypic plasticity in plant evolution. The intraspecific spatial variation in functional traits and their phenotypic plasticity can help predict species distribution, persistence and invasion under global climate change.

Anthropogenic activities and climate change contribute to the deterioration of wetlands worldwide with Central Asia (CA) being among the regions which are most severely affected. This study examined how the distribution of wetlands in CA has changed in the last two decades. Emphasis was put on inland wetlands protected as International Bird and Biodiversity Areas. Time series of maps of wetlands (i.e. reed beds) were created for the years 2000, 2005, 2010, 2015 and 2018. A supervised classification approach was applied using NDVI of MODIS satellite images with 1000m resolution for the respective years. Ground control points were acquired through fieldtrips to the lower Chu River, upper Ili River and Ili River Delta in Kazakhstan and the Amu Darya River Delta and the Lower Amu Darya State Biosphere Reserve in Uzbekistan. The applied method is not applicable for the classification of wetlands in northern Kazakhstan. The vegetation there is too alike to the wetland vegetation in terms of values and seasonality of NDVI. For the remaining part of the study area, the applied method delivers satisfying results. However, it is difficult to determine a general trend for most wetland areas since there is a large variability between years. This study marks a first attempt at examining wetlands in CA at a regional scale. The results provide a baseline for further, more detailed research through either fieldtrips or by using higher resolution remote sensing data.

The surrounding area of the Roxo stream sub-basin (basin of the Sado River, Portugal) has completely sterile sections, jeopardizing the productivity of the agricultural activities practiced there. This may be due, in addition to other factors, to the inflow of the Água Forte stream, which has characteristics of Acid Mining Drainage (AMD). The objective of this study was to test the efficiency of heavy metal removal from Água Forte stream using macrophyte floating bed technology (Vetiveria zizanioides and Phragmites australis) in a pilot plant, monitoring and evaluating water quality and performance of macrophytes. Two experiments were carried out in 2019 during 6 months (January to June). Both experiments were performed in a polyvinyl chloride (PVC) tanks of nominal capacity of 1 m3 each. The tanks were filled with about 0.8 m3 of water coming from Água Forte stream, which was renewed monthly. The floating beds consisted in a high density polyethylene flotation system and an organic plant support mat filled with a plant density of 285 plants.m-2. Heavy metal removal rates obtained from the Vetiveria zizanioides and Phragmites australis floating bed were: Fe = 40%; Zn = 33%; Cu = 23%; Mn = 14% and Fe = 27%; Zn = 19%; Mn = 17%; Cu = 14%; respectively. The order of accumulation of heavy metals in Vetiveria zizanioides and Phragmites australis in plant biomass was Fe> Zn> Cu> Mn and Fe> Zn> Mn> Cu, respectively. The growth of Vetiveria zizanioides and Phragmites australis in leaf biomass was 7.1 ± 0.3 cm / month and 2.5 ± 0.0 cm / month and in root biomass 3.8 ± 0.1 cm / month and 4.1 ± 0.1 cm / month, respectively. The growth of macrophytes showed the ability to survive in AMD-containing waters without severe damage in their external and anatomical morphology, although their growth suffered inhibition. The results suggest that floating bed technology may be an environmentally sustainable alternative, allowing long-term heavy metal removal.

The aim of the work was to evaluate the ability of Phragmites australis to uptake lead and nickel from the stream taking the treated poultry slaughterhouse wastewater (PSW). Pb and Ni concentrations, which are the priority substances of the water frame directive, were detected separately at the root, stem and leaf of P. australis at 50 m and 100 m from the downstream of discharge point. The uptake of Pb and Ni by P. australis followed the order of root > leaf > stem. The Ni uptake was higher than Pb uptake in P. australis exposed to poultry wastewater. As a result, P. australis exposed to PSW were found to have the ability to uptake Pb and Ni. It has been determined that P. australis can be used for removal and phytoremediation of Pb and Ni metals from PSWs.

Common reed (Phragmites australis) has high biomass production and is primarily subjected to decomposition processes affected by multiple factors. To predict litter decomposition dynamics in intermittent lakes, it is critical to understand how communities of fungi, as the primary decomposers, form under different habitat conditions. This study reports the shotgun metagenomic sequencing of the initial fungal communities on common reed leaves decomposing under different environmental conditions. We demonstrate that a complex network of fungi forms already on the plant persists into the decomposition phase. Phragmites australis leaves contained at least five fungal phyla, with abundant Ascomycota (95.7%) and Basidiomycota (4.1%), identified as saprotrophs (48.6%), pathotrophs (22.5%), and symbiotrophs (12.6%). Most of the correlations between fungi in fresh and decomposing leaves were identified as co-occurrences (positive correlations). The geographic source of litter and leaf age did not affect the structure and diversity of fungal communities. Keystone taxa were mostly moisture-sensitive. Our results suggest that habitat has a strong effect on the formation of the fungal communities through keystone taxa. Nevertheless, it can also alter the proportions of individual fungal groups in the community through indirect effects on competition between the fungal taxa and their exploitation of favourable conditions.

Wetlands provide vital services on which human societies depend. As they have been rapidly degrading due to anthropogenic impacts worldwide, wetland restoration is increasingly applied. When a return to the original state of a wetland is constrained, forward-looking restoration can provide a new way to enhance an ecosystem's ecological integrity. However, the direction in which new ecosystems will develop is strongly coupled to the initial environmental conditions and may benefit from active decisions on (future) management. To improve the natural values of a degrading freshwater lake in the Netherlands, a forward-looking restoration project was initiated in lake Markermeer in 2016, involving the construction of a 700-ha archipelago called the “Marker Wadden”. This archipelago should provide new habitat to higher trophic levels in the lake's food web through the development of currently missing Common reed ( Phragmites australis ) dominated marshlands with gradual land-water transitions. However, the restoration project faces strong grazing pressure by Greylag geese ( Anser anser ) that possibly inhibit reed establishment. Here, we aimed to unravel the effect of herbivory by Greylag geese (using exclosures) and the introduction of reed rhizomes on early vegetation development and carbon dynamics on the bare soils of this new ecosystem in a manipulative field experiment. Our results showed that excluding herbivores strongly increased reed-vegetation cover, density and maximum height, but only when reed rhizomes were actively introduced. Spontaneous vegetation development on bare soils was limited, and colonization by Broadleaf cattail ( Typha latifolia ) dominated over reed. Net ecosystem exchange of carbon and ecosystem respiration were strongly linked to vegetation development, with highest methane emissions in the most densely vegetated plots. We conclude that the establishment of reed marshes can strongly benefit from excluding herbivores and the introduction of reed, and that otherwise other vegetation types may establish more slowly in newly created wetlands. This illustrates how active management of vegetation development has the potential to benefit novel ecosystems.

Restoration efforts take place at large scales to improve the ecological value of degraded, modified river deltas. To anticipate on the implications of using dredged, estuarine sediment to restore wetlands in river deltas, we studied the development of Typha latifolia (cattail) and Phragmites australis (common reed) on two designated dredged sediments, virgin Holocene clay (clay) and eroded clay (mud), under different water levels (inundated, saturated, and moist) in a mesocosm experiment. The mud sediment contained about two times higher Fe, S, and P content and four times higher N-total content compared to clay sediment. The organic content was comparable for both sediments. Sediment type influenced germination and shoot growth of T. latifolia, which were both higher on clay compared to mud, but did not influence germination and initial growth of P. australis. Water level treatment effects on plant response were limited to inundation conditions only; this condition strongly reduced P. australis seedling and shoot development. Both species developed significantly more above- and belowground biomass when growing in mud compared to clay, however, their nutrient content was comparable on both sediment types. Overall, T. latifolia development was more strongly influenced by sediment composition compared to P. australis, but the latter species is more vulnerable to higher water levels during early stages of development. We conclude that both dredged sediment types are suitable as sediment for developing macrophyte vegetation.

Στην παρούσα διπλωματική εργασία μελετήθηκαν και βελτιστοποιήθηκαν ορισμένες παράμετροι κατασκευής και λειτουργίας της τεχνολογίας των Τεχνητών Υγροβιότοπων για την επεξεργασία διασταλάγματος από τον ΧΥΤΑ Χανίων. Το πείραμα περιέχει δυο μονάδες τεχνητών υγροβιότοπων οριζόντιας υποεπιφανειακής ροής, οι οποίες τοποθετήθηκαν στον υπαίθριο χώρο του θερμοκηπίου της Σχολής Χημικών Μηχανικών και Μηχανικών Περιβάλλοντος του Πολυτεχνείο Κρήτης. Το πληρωτικό υλικό και των δύο μονάδων είναι χαλίκι, ενώ στη μία από τις δύο μονάδες υπήρχε και ένα στρώμα από βιοεξανθράκωμα το οποίο παρήχθη από κλαδέματα ελιάς ως ένα υπόδειγμα κυκλικής διαχείρισης. Οι δύο πιλοτικές μονάδες χαρακτηρίζονται ως G (Gravel) και GΒ (Gravel & Biochar) και φυτεύτηκαν με κοινό καλάμι Phragmites Australis. Ως εισροή στις κλίνες εφαρμόστηκε διαστάλαγμα, το οποίο συλλεγόταν αμέσως μετά από το στάδιο της κροκίδωσης στη μονάδα επεξεργασίας διασταλάγματος στον ΧΥΤΑ Χανίων. Για μια συγκεκριμένη χρονική περίοδο του πειράματος γινόταν προσθήκη μεθανόλης και στις δύο μονάδες. Ο λειτουργικός όγκος των δύο κλινών ήταν 188,3L έκαστη και η μέση ημερήσια παροχή ήταν 3,3L/day. Οι αναλύσεις που πραγματοποιήθηκαν αφορούσαν την εισροή, την εκροή και τη φυτική βιομάζα των μονάδων. Πιο συγκεκριμένα για την εισροή και τις εκροές προσδιορίστηκαν οι εξής παράμετροι σε εβδομαδιαία βάση: BOD5, COD, NO3--N, NO2--N, NH4+-N, PO43--P, υδραυλική αγωγιμότητα, pH, μετάλλα και μεταλλοειδή. Οι αναλύσεις της φυτικής βιομάζας αποσκοπούσαν στον προσδιορισμό TN (ολικό άζωτο), TP (ολικό φώσφορο) και μετάλλων και μεταλλοειδών Τα αποτελέσματα των μέσων αποδόσεων για τις μονάδες G και GΒ είναι ως ακολούθως. Για το COD η απόδοση στη μονάδα G είναι 43,3 ± 13,3% και στη GΒ είναι 52,7 ± 15%. Για το ΝΟ3--Ν η απόδοση της μονάδας G ισούται με 78,2 ± 16,2%, ενώ για τη μονάδα GΒ η απόδοση αγγίζει το 93,4 ± 5,8%. Για το ΝΟ2--Ν η απόδοση είναι 94,9 ± 5,4% της μονάδας G και 99,0 ± 2,1% της μονάδας GΒ. Αναφορικά με το ΝΗ4+-Ν, η μονάδα G φτάνει στο 82,3 ± 9,8% και η μονάδα GΒ στο 87,6 ± 6,2%. Αντίστοιχα, η απόδοση για τα TSS είναι για τη μονάδα G 72,2 ± 14,8% και 66,3 ± 21,6% για την GΒ. Επιπλέον, η υδραυλική αγωγιμότητα παρουσιάζεται αυξημένη σε σχέση με την εισροή και στις δύο μονάδες λαμβάνοντας τις τιμές 10,72 ± 6,2 και 11,59 ± 7,1 στις G και GB αντίστοιχα, ενώ το pH είναι ελαφρώς αλκαλικό, επίσης BOD5 και PO43--P ήταν σχεδόν μη ανιχνεύσιμα στις εκροές των μονάδων G και GΒ. Τέλος, τα αποτελέσματα για τα μέταλλα και μεταλλοειδή έδειξαν ότι υπάρχουν ορισμένα στοιχεία που ανιχνεύονται σε υψηλότερες συγκεντρώσεις, όπως τα Β, Mg, K, Ca, Cu, Fe και Zn ωστόσο δεν υπερβαίνουν τα τυπικά νομοθετικά όρια εκροών δευτεροβάθμιας επεξεργασίας. Όσον αφορά τη φυτική βιομάζα διαπιστώνεται ότι τα φυτά έχουν κατά βάση την τάση να συγκρατούν ποσότητες φωσφόρου και αζώτου περισσότερο στα φύλλα τους και τους κορμούς τους, ενώ οι ποσότητες μετάλλων συγκρατούνται περισσότερο στις ρίζες. Το βασικό συμπέρασμα που προέκυψε είναι ότι η προσθήκη βιοεξανθρακώματος και μεθανόλης αυξάνει την απόδοση απομάκρυνσης ρύπων., In the context of the present thesis, the optimization of construction and operation parameters of constructed wetlands have been experimentally studied for the treatment of leachate from the landfill of Chania. The experiment concerns two horizontal subsurface flow constructed wetlands, which were placed in the outdoor area of the greenhouse of the School of Chemical and Environmental Engineering at the Technical University of Crete. Gravel was used as filling material to both units, while in one unit a layer of biochar was also placed. The units were labelled G (Gravel) and GB (Gravel & Βiochar) and were planted with the common reed Phragmites Australis. The inflow for the beds was leachate, which was collected after the flocculation stage at the leachate treatment plant of the Chania landfill. Moreover, methanol was added to both units at certain time period. The operating volume of each bed was 188.3 L and the average flow rate of volume for the units was 3.3L/day. The follow-up analyses concerned the inflow, outflow and the plant biomass of the units. More specifically, the inflow and outflows was analyzed for the determination of the following parameters: BOD5, COD, NO3--N, NO2--N, NH4+-N, PO43--P, Electrical Conductivity, pH, metals and metalloids. The analysis of the plant biomass aimed at the determination of TN (total Nitrogen), TP (total Phosphorus), metals and metalloids. The results of the mean yields for the G and GB units are as follows. For COD the efficiency in unit G was 43,3 ± 13,3% and in unit GB is 52,7 ± 15%. For NO3--N the yield of unit G was equal to 78,2 ± 16,2%, while for unit GB the yield reached 93,4 ± 5,8%. For NO2--N the yield was 94,9 ± 5,4% of the G unit and 99,0 ± 2,1% of the GB unit. Regarding NH4+-N, the unit G reached 82,3 ± 9,8% and the unit GB 87,6 ± 6,2%. Respectively, the yield for TSS was for unit G at 72,2 ± 14,8% and 66,3 ± 21,6% for GB. Moreover, the Electrical Conductivity seems to be higher than the inflow taking the values10,72 ± 6,2 and 11,59 ± 7,1 for units G and GB , while the pH is slightly alkaline. Also, BOD5 and PO43--P were almost undetectable in the outflows of the G and GB units. Finally, the results for metals and metalloids showed that there are some elements that are detected at higher concentrations, such as B, Mg, K, Ca, Cu, Fe and Zn, but they do not exceed the standard legal secondary wastewater effluent limits. Regarding plant biomass, it is found that plants basically tend to retain amounts of phosphorus and nitrogen more in their leaves and stems, while minerals retained in roots. The main conclusion is that the addition of biochar and methanol increases the pollutants’ removal efficiency.

Per- and polyfluoroalkyl substances (PFASs) have multiple emission sources, from industrial to domestic, and their high persistence and mobility help them to spread in all the networks of watercourses. Diffuse pollution of these compounds can be potentially mitigated by the application of green infrastructures, which are a pillar of the EU Green Deal. In this context, a phytoremediation pilot plant was realised and supplied by a contaminated well-located in Lonigo (Veneto Region, Italy) where surface and groundwaters were significantly impacted by perfluoroalkyl acids (PFAAs) discharges from a fluorochemical factory. The investigation involved the detection of perfluorobutanoic acid (PFBA), perfluorooctanoic acid (PFOA), perfluorobutanesulfonic acid (PFBS) and perfluorooctanesulfonic acid (PFOS) inside the inlet and outlet waters of the phytoremediation pilot plant as well as in reed grasses grown into its main tank. The obtained results demonstrate that the pilot plant is able to reduce up to 50% of considered PFAAs in terms of mass flow without an evident dependence on physico-chemical characteristics of these contaminants. Moreover, PFAAs were found in the exposed reed grasses at concentrations up to 13 ng g−1 ww. A positive correlation between PFAA concentration in plants and exposure time was also observed. In conclusion, this paper highlights the potential efficiency of phytodepuration in PFAS removal and recommends improving the knowledge about its application in constructed wetlands as a highly sustainable choice in wastewater remediation.

Microphytes are of great ecological importance and make up the majority of primary producers in aquatic environments. In ponds, their communities can be affected by fertilisation and supplemental feeding, a common management practise in fish farming that reduces pond water. The aim of the study was to investigate the epiphytic microphytes of common reed (Phragmites australis) in late autumn in four common carp (Cyprinus carpio Linnaeus, 1758) ponds in Donji Miholjac and Grudnjak. At each site, one pond with young-of- the-year and one pond with adult common carps were investigated. The ponds differed in physical and chemical parameters – water depth (0.80 - 2.45 m), dissolved oxygen concentration (3.75 - 12.88 mg/L), ammonium (0.11 - 0.89 mg/L), phosphates (0.15 - 0.78 mg/L), and chlorophyll-a concentration (7.81 to 53.09 µg/L). Water temperature was in accordance with seasonal conditions and similar in all ponds (8.7 - 9.0 °C). Epiphytic communities were diverse (> 100 taxa) and included most taxa from the Bacillariophyceae and Chlorophyta groups in all ponds. Further studies should focus on changes in epiphytic community composition and abundance as a function of season and supplemental feeding applied.

Tidal marshes are increasingly valued for their nature-based shoreline protection function, as they reduce waves, currents and erosion. The effectiveness of this function depends on the ability of tidal marsh plants to grow and survive under pressure from waves and currents. However, how this varies with species-dependent plant traits is poorly understood. We performed a field transplantation experiment to quantify species-specific growth responses to different levels of hydrodynamic exposure and tidal inundation for 3 NW European marsh species: Schoenoplectus tabernaemontani, Bolboschoenus maritimus and Phragmites australis. In this order, these species showed increasing shoot stiffness, length and biomass, which are traits that increase hydrodynamic drag forces experienced by plants. Increased exposure to tidal inundation and hydrodynamics reduced the growth of all 3 species, but species with lower biomass and shorter, thinner and more flexible shoots could better cope with higher hydrodynamic exposure and tidal inundation. Furthermore, transplants of S. tabernaemontani (i.e. the species with the lowest shoot stiffness, length and biomass that survived under all tested conditions) developed smaller, thinner and more flexible shoots in response to higher hydrodynamic exposure and inundation. Hence our study indicates that similar inter- and intra-specific plant traits drive plant growth in response to hydrodynamics and inundation. This suggests that the spatial distribution of species typically observed in tidal marshes results not only from species-specific tolerance to tidal inundation gradients but also from hydrodynamic gradients. Allowing enough space for development of species zonation may be important to increase the efficiency of nature-based shoreline protection by tidal marshes.

Aquatic vegetation loss caused substantial decrease of ecosystem processes and services during the last decades, particularly for the capacity of these ecosystems to sequester and store carbon from the atmosphere. This study investigated the extent of aquatic emergent vegetation loss for the period 1985–2018 and the consequent effects on carbon sequestration and storage capacity of Valle Santa wetland, a protected freshwater wetland dominated by Phragmites australis located in the Po river delta Park (Northern Italy), as a function of primary productivity and biomass decomposition, assessed by means of satellite images and experimental measures. The results showed an extended loss of aquatic vegetated habitats during the considered period, with 1989 being the year with higher productivity. The mean breakdown rates of P. australis were 0.00532 d−1 and 0.00228 d−1 for leaf and stem carbon content, respectively, leading to a predicted annual decomposition of 64.6% of the total biomass carbon. For 2018 the carbon sequestration capacity was estimated equal to 0.249 kg C m−2 yr−1, while the carbon storage of the whole wetland was 1.75 × 103 t C (0.70 kg C m−2). Nonetheless, despite the protection efforts over time, the vegetation loss occurred during the last decades significantly decreased carbon sequestration and storage by 51.6%, when comparing 2018 and 1989. No statistically significant effects were found for water descriptors. This study demonstrated that P. australis-dominated wetlands support important ecosystem processes and should be regarded as an important carbon sink under an ecosystem services perspective, with the aim to maximize their capacity to mitigate climate change.

The construction industry has seen a growing emphasis on the use of sustainable materials in recent years. This is driven by various factors, including a desire to reduce environmental impact, improve indoor air quality, and promote the health and well-being of building occupants. One sustainable material that is being increasingly utilized in construction is natural fibers. Phragmites australis fibers, in particular, are renewable, biodegradable, and have a low carbon footprint. The present study aims to evaluate the impact of Phragmites australis fibers on the behavior of reinforced concrete beams. Five concrete mixes were utilized in the experiment, with the control mix having a 1:1.5:3 ratio of cement to sand to coarse aggregate by weight. The other four mixes incorporated Phragmites australis fibers at 0%, 0.5%, 1%, and 1.5% of the volume of the mix, with cement replaced by 10% glass by weight. The water-to-cement ratio was set at 0.4 for all mixes. Concrete cubes, cylinders, and prisms were prepared to determine mechanical and physical properties, while reinforced concrete beams were used to assess structural performance. The results of the experiment showed that the addition of Phragmites australis fibers slightly decreased the compressive and tensile strength of the concrete compared to the control mix. However, the inclusion of 0.5% Phragmites australis fibers enhanced the split tensile and flexural strength of the concrete. In terms of reinforced concrete beams, the maximum load-bearing capacity was realized for the mix with 10% glass and 0% Phragmites australis fibers. However, the highest ductility index and deflection were achieved for the mix with 10% glass and 0.5% Phragmites australis fibers. Therefore, the use of Phragmites australis fibers can improve the structural performance of concrete.

This contribution discusses the use of field measurements and remotely sensed data in an exploration of the effects of environmental parameters on the riparian and littoral stands of the common reed (Phragmites australis) in an intermittent wetland in Slovenia. For this purpose, we created a normalized difference vegetation index (NDVI) time series extending from 2017 to 2021. Data were collected and fitted to a unimodal growth model, from which we determined three different stages relating to the reed’s growth. The field data consisted of the above-ground biomass harvested at the end of the vegetation season. Maximal NDVI values at the peak of the growing season exhibited no useful relationship with the above-ground biomass at the end of the season. Intense and long-lasting floods, especially during the period of intense culm growth, hindered the production of common reeds, while dry periods and temperatures were helpful before reed growth began. Summer droughts exhibited little effect. Water level fluctuations exerted a greater effect on reeds at the littoral site due to more pronounced extremes. In contrast, more constant and moderate conditions at the riparian site benefited the growth and productivity of the common reed. These results can prove useful for decision making regarding common reed management at the intermittent lake Cerknica.

Strategies for remediation of per- and polyfluoroalkyl substances (PFAS) generally prioritise highly contaminated source areas. However, the mobility of PFAS in the environment often results in extensive low-level contamination of surface waters across broad areas. Constructed Floating Wetlands (CFWs) promote the growth of plants in buoyant structures where pollutants are assimilated into plant biomass. This study examined the hydroponic growth of Juncus krausii, Baumea articulata and Phragmites australis over a 28-day period for remediation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) contaminated (0.2 µg/L to 30 µg/L) urban stormwater. With increasing PFOA and PFOS concentrations, accumulation in plant species increased although root and shoot distribution varied depending on PFAS functional group. Less PFOA than PFOS accumulated in plant roots (0.006–0.16 versus 0.008–0.68 µg/g), while more PFOA accumulated in the plant shoots (0.02–0.55 versus 0.01–0.16 µg/g) indicating translocation to upper plant portions. Phragmites australis accumulated the highest overall plant tissue concentrations of PFOA and PFOS. The NanoSIMS data demonstrated that PFAS associated with roots and shoots was absorbed and not just surface bound. These results illustrate that CFWs have the potential to be used to reduce PFAS contaminants in surface waters. Refereed/Peer-reviewed

Background The lateral movements of mass and energy across the terrestrial-aquatic interface are being increasingly recognized for their importance in the carbon (C) balance of coastal/estuarine wetlands. We quantified the lateral flux of detrital C in the Yangtze estuary where invasive Spartina alterniflora has substantially and extensively altered the ecosystem structure and functions. Our overall objective was to close the C budget of estuarine wetlands through field sampling, tower-based measurements, and modeling. Methods A lateral detrital C exchange evaluation platform was established in a case study of the Yangtze River Estuary to investigate the effect of ecosystem structural changes on lateral detrital C transfer processes. This study estimated the lateral detrital C exchange based on the gross primary production (GPP) by performing coupled modeling and field sampling. Tower-based measurements and MODIS time series and CH4 outgassing and biomass simultaneously measured the lateral detrital C flux to characterize the relative contributions of lateral (i.e., detritus) C fluxes to the annual marsh C budget. Results The C pools in the plants and soil of Spartina marshes were significantly higher than those of the native community dominated by Phragmites australis. The GPP based on MODIS (GPPMODIS) was 472.6 g C m−2 year−1 and accounted for 73.0% of the GPP estimated from eddy covariance towers (GPPEC) (646.9 ± 70.7 g C m−2 year−1). We also detected a higher GPPMODIS during the pre-growing season, which exhibited a similar lateral detrital C flux magnitude. On average, 25.8% of the net primary production (NPP), which ranged from 0.21 to 0.30 kg C m−2 year−1, was exported during lateral exchange. The annual C loss as CH4 was estimated to be 17.9 ± 3.7 g C m−2 year−1, accounting for 2.8% of the GPPEC. The net positive detrital C flux (i.e., more detritus leaving the wetlands), which could exceed 0.16 kg C m−2 day−1, was related to daily tides. However, the observed lateral detrital C flux based on monthly sampling was 73.5% higher than that based on daily sampling (i.e., the sum of daily sampling), particularly in March and October. In addition, spatiotemporal granularities were responsible for most of the uncertainty in the lateral detrital C exchange. Conclusion This research demonstrated that an integrated framework incorporating modeling and field sampling can quantitatively assess lateral detrital C transport processes across the terrestrial-aquatic interface in estuarine wetlands. However, we note some limitations in the application of the light-use efficiency model to tidal wetlands. Spartina invasion can turn the lateral C balance from a C source (209.0 g C m−2 year−1) of Phragmites-dominated marshes into a small C sink (-31.0 g C m−2 year−1). Sampling over a more extended period and continuous measurements are essential for determining the contribution of different lateral detrital C flux processes to closing the ecosystem C budgets. The sampling spatiotemporal granularities can be key to assessing lateral detrital C transfer.

Mine drainage is a vital water problem in the mining industry worldwide because of the heavy metal elements and low pH. Rhizofiltration using wetland plants is an appropriate method to remove heavy metals from the water via accumulation in the rhizosphere. Phragmites australis is one of the candidate plants for this method because of metal accumulation, forming iron plaque around the roots. At the study site, which was the mill tailings pond in the Ningyo-toge uranium mine, P. australis has been naturally growing since 1998. The results showed that P. australis accumulated Fe, Mn, and 238U in the nodal roots without/with iron plaque compared with other plant tissues. Among the 837 bacterial colonies isolated from nodal roots, 88.6% showed siderophore production activities. Considering iron plaque formation around P. australis roots, we hypothesized that microbial siderophores might influence iron plaque formation because bacterial siderophores have catechol-like functional groups. The complex of catechol or other phenolics with Fe was precipitated due to the networks between Fe and phenolic derivatives. The experiment using bacterial products of root endophytes, such as Pseudomonas spp. and Rhizobium spp., showed precipitation with Fe ions, and we confirmed that several Pseudomonas spp. and Rhizobium spp. produced unidentified phenolic compounds. In conclusion, root-endophytic bacteria such as Pseudomonas spp. and Rhizobium spp., isolated from metal-accumulating roots of P. australis, might influence iron plaque formation as the metal accumulation site. Iron plaque formation is related to tolerance in P. australis, and Pseudomonas spp. and Rhizobium spp. might indirectly contribute to tolerance. Although there are many issues to be resolved in this research, we hope that the fundamental analysis of plant-microbe interactions would be helpful for phytoremediation at mine sites.

Wetlands have degraded dramatically in recent decades due to wetland drainage, agricultural reclamation, and soil salinization in China. Soil seed banks, as a way of natural regeneration, can efficiently restore the aboveground vegetation if seeds can survive after farming. To explore the response of soil seed bank to farming and consequent environmental changes, we compared the structure and composition of soil seed banks between Carex-dominated and Phragmites-dominated natural wetlands and their adjacent farmed fields in the Songnen Plain, China. We found that the responses of soil seed banks to farming and saline-alkaline stress were different between the two community types. The seed density and species richness in Carex-dominated natural wetlands were significantly higher than nearby farmed fields, however, there was no significant difference between Phragmites-dominated natural wetlands and nearby farmed fields. Carex schmidtii and Phragmites australis, dominated in natural wetlands, were both missing after farming. At the same time, the invasive species Typha angustifolia dominated in the farmed fields. Redundancy analysis identified that soil salt content was one of the major factors which significantly affected seed bank composition. Saline-alkaline stress significantly restricted the seed germination in farmed Carex fields, however, it had no significant effect in farmed Phragmites fields. Our study indicated that the potential of vegetation restoration was restricted by seed limit and soil salinization, and it differed significantly between the original community types in the Songnen Plain. In addition to hydrological connection, special technologies (such as planting and seeding) and the improvement of soil conditions are also necessary for successful restoration in salt-affected wetlands.

This experiment aimed to study the effects on liver tissue structure and immune performance of grass carp Ctenopharyngodon idellus when the common reed Phragmites australis is in its diet, instead of wheat Triticum aestivum L. Seventy-two healthy grass carps (145.52 ± 2.56 g) were randomly divided into three groups according to their body weight. Fishes in each group were fed an essential diet with 0% (control group), 50% and 100% (test group) common reed, instead of wheat, respectively. After feeding for 41 days, the changes of serum biochemical indices, liver tissue structure and immune related indices of grass carp were detected. The results showed that, compared with the control group, the activities of serum alanine transaminase (ALT) and aspartate transaminase (AST) in the substitution groups were significantly increased (p < 0.05), but still at a normal level. The contents of total protein, albumin and globulin did not change significantly (p > 0.05). Compared with the control group, the liver cells of grass carp in the substitution groups had clear boundaries, tight arrangement and less vacuolation. The contents of serum interleukin-1 (IL-1) and complement 3 (C3) in the 100% substitution group were significantly higher than those in the control group (p < 0.05), and the contents of liver IL-1 and total complement (CH50) in the 100% substitution group were significantly higher than those in the control group (p < 0.05). The contents of IL-1, C3 in serum and IL-1, CH50 in liver in the 50% substitution group were significantly higher than those in the control group (p < 0.05). The mRNA relative expression levels of C3, IL-1, MHC-I and interferon (IFN) in the head-kidney, kidney, liver and spleen of grass carp were significantly affected by feeding the grass carp with different common reed substitution ratios (p < 0.05). In summary, common reed, instead of wheat, in feed can improve the liver tissue structure, and increase the non-specific immune response level, of grass carp.

Inundation shifts plant growth, species diversity and ecosystem stability, but it remains unclear how inundation depth shapes the phenotypic variability of clonal plants in an estuary wetland. To reveal the response of clonal plant populations to inundation depth, we calculated the variation of Phragmites australis using shoot height, leaf length, leaf width, leaf biomass and panicle length in the Liaohe estuary wetland. Reproductive allocation was defined by the ratio of panicle length to shoot height. Linear regression showed that shoot height, leaf length, leaf width, leaf biomass and panicle length were negatively correlated with inundation depth, while the ratio of panicle length to shoot height was negatively correlated with inundation depth (p < 0.0001). Based on data regarding the statistical differences of plant phenotypic traits among P. australis, we recognized populations had generated variation differentiation. Compared with other functional traits, the coefficient of variation of leaf-related traits were at a high level. Therefore, leaf parameters would be the most suitable, and they increased the area and weight to support the action of plants during floods. Multivariate statistical analysis suggested that P. australis populations in the Liaohe estuary wetland were divided into two phenotypic clusters, consistent with geographical distance and morphological similarity. Our results provide a novel perspective on the ecological strategy of cloned plants under inundation change and offer theories for the conservation and restoration of estuarine wetland ecosystems.

Common reed (Phragmites australis) can invade and dominate in its natural habitat which is mainly wetlands. It can tolerate harsh environments as well as remediate polluted and environmental degraded sites such as mine dumps and other polluted wastelands. For this reason, this can be a very critical reed to reclaim wastelands for agricultural use to ensure sustainability. The present review manuscript examined the microbial spectra of P. australis as recorded in various recent studies, its physiological response when growing under stress as well as complementation between rhizosphere microbes and physiological responses which result in plant growth promotion in the process of phytoremediation. Microbes associated with P. australis include Proteobacteria, Bacteriodetes, and Firmicutes, Fusobacteria, Actinobacteria, and Planctomycetes families of bacteria among others. Some of these microbes and arbuscular mycorrhizal fungi have facilitated plant growth and phytoremediation by P. australis. This is worthwhile considering that there are vast areas of polluted and wasted land which require reclamation for agricultural use. Common reed with its associated rhizosphere microbes can be utilized in these land reclamation efforts. This present study suggests further work to identify microbes which when administered to P. australis can stimulate its growth in polluted environments and help in land reclamation efforts for agricultural use.

Most phytoremediation studies are limited to several of the most common plants and in most cases these studies are performed to a very limited extent. There are also few publications on the assessment of the effectiveness of the removal of pollutants, performed simultaneously with various plants and using physicochemical analyses as well as toxicity tests. Therefore, the conducted studies focused on assessing the removal of pollutants from leachate by physicochemical analyses and toxicity tests. The leachate was collected from four municipal waste landfills of different ages (2 non-operational facilities and 2 active). The studies were conducted for two biological systems: using emergent macrophytes (Phragmites australis) and submergent macrophytes (Ceratophyllum demersum L.). It has been observed that efficiency of biological treatment of leachates with Phragmites australis and Ceratophyllum demersum shows significant differences at lower concentrations of solutions. Even after the treatment with Phragmites australis and Ceratophyllum demersum, the analyzed leachate samples produced a toxic effect on the test organisms. A reduction or no toxicity of the leachate after the biological treatment was observed only in some cases. The observed effects of the biological leachate treatment were not conclusive. Particular attention should be paid to the persistent toxicity, which can pose a real threat to the environment when discharging leachates after treatment.

[EN] Continuous phosphorus discharges in bodies of water, generated by human activities, such as agriculture, domestic effluences or wastewater from industrial processes, produce contaminated water and eutrophication. For this reason, efficient and low-cost systems that can remove phosphorus from contaminated water are necessary. In addition, it is important to generate renewable energy such as the energy produced in biomass power plants, taking advantage of the available biomass waste in each place. When producing this renewable energy, the resulting ash is a residue that can be used for phosphorus removal by adsorption processes. Moreover, according to the concept of the circular economy, the ash waste generated in this bio energy process should be reduced as much as possible. One of the advantages of this research being that surplus phosphorus-laden ash can be reused as fertilizer in agricultural fields. Considering this, the efficiency of reed ash (RA) (Phragmites australis) has been analysed in batch experiments, as well as the effect of several parameters on the removal of phosphate, such as contact time, phosphate-ash ratio, ash dose and temperature. Significant results obtained show that RA can be used to improve water quality.

Arundo donax, Cortaderia selloana and Phragmites australis are high-biomass-producing perennial Poalean species that grow abundantly and spontaneously in warm temperate regions, such as in Mediterranean-type climates, like those of Southern Europe, Western United States coastal areas, or in regions of South America, South Africa and Australia. Given their vigorous and spontaneous growth, biomass from the studied grasses often accumulates excessively in unmanaged agro-forestry areas. Nonetheless, this also creates the demand and opportunity for the valorisation of these biomass sources, particularly their cell wall polymers, for biorefining applications. By contrast, a related crop, Miscanthus × giganteus, is a perennial grass that has been extensively studied for lignocellulosic biomass production, as it can grow on low-input agricultural systems in colder climates. In this study Fourier transform mid-infrared spectroscopy (FTIR), high-performance anion-exchange chromatography (HPAEC) and lignin content determinations were used for a comparative compositional characterisation of A. donax, C. selloana and P. australis harvested from the wild, in relation to a trial field-grown M. × giganteus high-yielding genotype. A high-throughput saccharification assay showed relatively high sugar release values from the wild-grown grasses, even with a 0.1M NaOH mild alkali pretreatment. In addition to this alkaline pretreatment, biomass was treated with white-rot fungi (WRF), which preferentially degrade lignin more readily than holocellulose. Three fungal species were used: Ganoderma lucidum, Pleurotus ostreatus and Trametes versicolor. Our results showed that neutral sugar contents are not significantly altered, while some lignin is lost during the pretreatments. Furthermore, sugar release upon enzymatic saccharification was enhanced, and this was dependent on the plant biomass and fungal species used in the treatment. To maximise the potential for lignocellulose valorisation, the liquid fractions from the pretreatments were analysed by high performance liquid chromatography – photodiode array detection – electrospray ionisation tandem mass spectrometry (HPLC-PDA-ESI-MSn). This study is one of the first to report on the composition of WRF-treated grass biomass, while assessing the potential relevance of breakdown products released during the treatments, beyond more traditional sugar-for-energy applications. Ultimately, we expect that our data will help promote the valorisation of unused biomass resources, create economic value, while contributing to the implementation of sustainable biorefining systems.