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Production of fermentable sugars from renewable lignocellulosic biomass could provide a sustainable substrate for biofuel production by microbial fermentation. However, the inherent structure of lignocellulose largely hinders enzymatic saccharification efficiency to obtain sugars, thus the development of efficient pretreatment methods to reduce biomass recalcitrance is an important issue. In this study, the effects of two typical processes including hydrothermal (HTP) and citric acid pretreatments (CAP) on the enzymatic hydrolysis yield of reed biomass were investigated. The results indicate that, when performing HTP at 180 °C for 120 min to deconstruct reed, the pretreated biomass led to a higher glucose yield of 87.1% after 72 h enzymatic hydrolysis with cellulase (10 FPU/g substrate). Furthermore, under the pretreatment conditions with 6% (w/v) citric acid, 150 °C, and 60 min, the glucose yield of pretreated reed was 63.4% after hydrolysis with cellulase (10 FPU/g substrate). In this case, adding Tween 80 (100 mg/g substrate) significantly facilitated the enzymatic saccharification activity resulting in the glucose yield of CA-pretreated reed to 84.2%. Compared with the untreated reed, the glucose yield of pretreated residues after HTP and CAP was largely improved by 4.97–5.18 folds which was mainly due to the enhanced crystallinity (50.0–53.2% vs. 45.9%). The total fermentable sugars of 34.7–34.8 g can be produced from 100 g of raw reed biomass based on the proposed HTP and CAP processes. The mechanism of enhanced enzymatic hydrolysis after pretreatments was elucidated through physicochemical characterization techniques. In summary, the proposed pretreatments show high potential application for biorefinery from renewable, abundant reed biomass. [ABSTRACT FROM AUTHOR]

To adapt to a habitat, halophytes growing at the same saline–alkali levels develop their unique rhizosphere microbial communities, whereas same plant species growing at different saline–alkali levels have different rhizosphere microbial communities. Therefore, understanding the rhizosphere microbial community structure of halophytes in different saline–alkali soils can help explore the microbial diversity and functional potential of important soil microorganisms. In this study, rhizosphere soils of three typical halophytes, namely, Halocnemum strobilaceum, Phragmites communis, and Halostachys caspica, growing at severe, heavy, and moderate saline–alkali soils, respectively, were collected from southern Xinjiang. The community structure and physicochemical properties of fungal species in the total nine rhizosphere soils were investigated. Furthermore, the differences in the fungal community structure, diversity, and ecological functions were analyzed in terms of the extent of saline–alkali level and host plant specificity. Rhizosphere soils in the nine habitats had different physicochemical properties. In terms of host plant type, rhizosphere fungal species diversity and richness were the highest in P. communis, followed by H. caspica and H. strobilaceum. The fungal community diversity and richness followed the pattern of moderate > severe > heavy in different soil salinity and alkali types. Although the three host plants had similar rhizosphere fungal community structures under moderate and heavy saline–alkali conditions, these varied significantly under extremely severe saline–alkali conditions. In total, 315 species were identified across all samples, and they were affiliated with 12 phyla, 37 classes, 69 orders, 138 families, and 244 genera. The number of jointly owned ASVs was 189. In the nine habitats, Ascomycota and Basidiomycota were the dominant phyla, while Alternaria, Neocamarosporium, Filobasidium, and Acremonium were the common dominant genera. A prediction of fungal community functions revealed pathotroph-saprotroph-symbiotroph and saprotrophs to be dominant. At the same saline–alkali level, the functional clustering distance of fungal communities was closer. Factors such as soil organic matter (SOM), available nitrogen (AN), electronic conductivity (EC), and pH contributed to the distribution of microbial communities. This study revealed both similarities and distinctions in the composition of fungal communities within the rhizosphere soils of the three typical halophytes thriving in various saline–alkali habitats. At moderate and heavy saline–alkali levels, the fungal community structures were markedly influenced by the severity of salinity and alkalinity. In extremely severe saline–alkali soils, the host plant type significantly affected the fungal community structure. Ultimately, these findings lay a theoretical foundation for the improvement of soil and crop yield in saline–alkali land. [ABSTRACT FROM AUTHOR]

Seed-based revegetation is increasingly pursued in wetland restoration, but seed and seedling mortality is high and can be further limited by environmental stressors, like hydrology and salinity. The interactive effects of hydrology and salinity on native plants, especially in the presence of invasive plants, are less clear. In greenhouse and mesocosm experiments, we tested different hydrologic and salinity conditions on the growth of native seed mixes and Phragmites australis, a widespread wetland invader in North America. The greenhouse experiment tested two mixes (forb mix, graminoid mix), while mixes in the mesocosm experiment combined forbs and graminoids chosen for broad and diverging environmental tolerances. In both experiments, reduced water negatively affected native plants and P. australis, while increased salinities reduced native plant growth but had minimal impacts on P. australis. In the greenhouse experiment, forbs greatly reduced P. australis growth only under benign conditions but maintained growth under increasing abiotic stress despite the presence of P. australis. In the mesocosm experiment, native plants reduced P. australis growth across all conditions, indicating that mixes chosen for broad environmental tolerances can sufficiently reduce invasive growth even when negatively affected by abiotic stressors. Our results demonstrate the varying drivers of invasion resistance: sometimes environmental conditions and species’ tolerances limit invasives and other times, the composition and competitive potential of the native community is more important. These results also inform wetland restoration practices, i.e., choosing species for revegetation mixes with broad environmental tolerances and, when possible, manipulating wetland environmental conditions to reduce invader performance. [ABSTRACT FROM AUTHOR]

Phragmites australis (Reed) is an excellent lignocellulosic crop for bioethanol production, but its recalcitrant structure affects utilization efficiency. Therefore, the effective pretreated method to destroy the complex and tight structure was necessary. In this study, Irradiation (0,400,800 kGy) combined with sodium hydroxide (NaOH) (0,1%,2%,4%) pretreatment was used for the deconstruct lignocellulose structure of reed stalk, and the residue after pretreatment were subjected to enzymatic hydrolysis and synchronous saccharification and fermentation (SSF). Scanning electron microscope (SEM), Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to determine the structural changes of reed stalk after different pretreatment. Gas Chromatography and Mass Spectrometry (GC/MS) was used to analysis the main lignocellulose-derived inhibitor produced by pretreatment. The results demonstrated that irradiation combined with NaOH pretreatment could destroy the lignocellulose structure, remove the lignin and hemicellulose partially, increase the content of cellulose, and promote fermentable sugar content for ethanol fermentation. The maximum enzymatic hydrolysis conversion rate of cellulose was 85.02% when the reed stalk was treated by 800 kGy irradiation combined with 4% NaOH solution. The maximum ethanol conversion rate was 73.35% when the reed stalk was pretreated by 800 kGy irradiation combined with 2% NaOH solution. Irradiation pretreatment destroyed the tightly packed structure, induced the fracture of hydrogen bond or covalent bond of reed stalk lignocellulose, broken the crystal structure of cellulose. Irradiation combined with NaOH treatment, the characteristic peak intensity of hemicellulose and lignin decreased or even disappeared in FT-IR spectroscopy. Interestingly, the cellulose crystal form transformed from I to II, when the reed stalk was treated by 800 kGy irradiation combined with NaOH solution. Overall, irradiation combined with NaOH pretreatment was effective for improving the utilization efficiency of reed stalk. [ABSTRACT FROM AUTHOR]

The study explores a synergistic two-phase system to treat olive mill wastewater (OMW), comprising a multilayer adsorbent filter (pretreatment) and a vertical flow constructed wetland (VFCW). The pretreatment phase includes layers of commercial granular activated carbon (CGAC) and volcanic tuff (VT), while the VFCW phase consists of planted tank with Phragmites australis reeds and unplanted tanks. Initially, municipal wastewater is introduced into the VFCW to establish the required microbial community. Then, pre-treated OMW is passed through the VFCW. The removal rates of various pollutants were assessed. The planted VFCW showed superior removal efficiencies, averaging 97.82% for total chemical oxygen demand (CODT), 92.78% for dissolved oxygen demand (CODd), 99.61% for total phenolic compounds (TPC), 98.94% for total nitrogen (TN), 96.96% for ammonium, and 95.83% for nitrate. In contrast, the unplanted VFCW displayed lower removal efficiencies, averaging 91.47% for CODT, 77.82% for CODd, 98.53% for TPC, 97.51% for TN, 92.04% for ammonium, and 90.82% for nitrate. These findings highlight the significant potential of VFCWs, which offer an integrated approach to OMW treatment by incorporating physical, chemical, and biological mechanisms within a single treatment system. [ABSTRACT FROM AUTHOR]

Freshwater macrophytes have attracted interest as an alternative source of natural extracts and minerals for a variety of therapeutic uses. However, few studies have rigorously investigated the phytochemical components, properties, and potential biological benefits of Phragmites australis as an emergent macrophyte. This study investigates the phytochemical profile of aqueous Phragmites australis (PAE) leaves extract using chromatographic-mass spectrometry and free radical scavenging analysis. LC-QToF-MS/MS analysis in both positive and negative ionization revealed the existence of thirty and eleven bioactive compounds, respectively tentatively identified as alkaloids, flavonoids, indoles, glycosides, and quinolines from the extract. The polyphenolic content of the PAE was found to be 39.17 ± 0.65 mg GAE/g total phenol, while the flavonoids content was 19.85 ± 2.64 mg QE/g, and proanthocyanins content was 119.65 ± 1.70 CE/g. The PAE was utilized to synthesize silver nanoparticles (AgNPs) to evaluate its nano-structural formation efficiency, with the PAE displaying a greater ability to scavenge free radicals against ABTS, DPPH, and FRAP when compared with PA-AgNPs. Both PAE and PA-AgNPs were tested for their antimicrobial and anticancer activities and the results indicated that PA-AgNPs (MIC value range of 7.8–62.5 µg/mL) had excellent antimicrobial activity, compared to PAE. Moreover, the antiproliferative effect of PA-AgNPs on human cancer cells showed a higher cell-specific dose response and two-fold apoptotic induction with increased phosphorylation in the DNA ss-strand break post-treatment in MCF-7 than in A549 cells. These findings reveal the potential of the leaf extract of PA as a potent antioxidant source for many biological applications. [ABSTRACT FROM AUTHOR]

Aims: Previous studies have shown that silicon (Si) can affect plant growth and yield by regulating the availability of other nutrients. However, the mechanisms by which Si affects plant biomass accumulation in coastal wetlands are not well explored. Methods: We conducted a sampling campaign across the whole growing season of Phragmites australis under waterlogging and drought conditions in coastal wetland, and quantified the effects of Si availability on biomass accumulation. Results: Compared with drought condition, the waterlogged condition improved the utilization efficiency of nitrogen (N) and phosphorus (P) of P. australis regulated by higher Si contents. Meanwhile, the increased Si contents promoted the utilization of N and P in leaf, suggesting that the increase in Si contents optimizes the photosynthetic process. Lignin contents in P. australis decreased with the increasing Si contents, which confirmed that Si can replace structural carbon components. In addition, principal component analysis (PCA) showed aboveground biomass accumulation of P. australis was synchronized with Si accumulation, indicating that Si was a beneficial element to promote biomass accumulation. Conclusions: Our study implies that increasing Si availability is conducive to biomass accumulation of P. australis in waterlogged wetlands, which will provide important scientific references for the management of coastal wetland ecosystem and the increase of global 'blue carbon' sequestration. [ABSTRACT FROM AUTHOR]

The study presented here reports the concentration of major, trace, and rare earth elements in soil, sediments, and vegetation samples collected from 13 locations around Anapa City located on the northern coast of the Black Sea in Russia. The neutron activation analysis technique has been used to fulfill this objective. Along with this, the bioconcentration and translocation factors were calculated. Overall, the content of 31 elements was detected in soil and sediments while 20 elements were determined in three types of vegetation: macroalgae (Cystoseira sp. and Ulva sp.), aquatic plants (Phragmites australis), and sea grass (Zostera sp.). The quantified concentration followed the order soil > sediment > vegetation. The phytotoxic levels for Zn, V, Mn, and Fe have been quantified as the highest. Bromine was the most abundant and accumulated in Phragmites australis. Based on the results obtained from this investigation, there is a possibility of contamination in the study area. [ABSTRACT FROM AUTHOR]

Background and aims: Soil alkaline salinity restricts the deep utilization of land resources. Research on the composition and diversity of plant rhizosphere microbial communities in saline-alkaline soils is helpful for identifying important microbial functional groups or functional potential, which is of great significance for vegetation restoration and ecological reconstruction. Methods: Bacteria colonized the rhizosphere soil of three halophytes grown in desert grasslands, including Halocnemum strobilaceum (HS), Phragmites communis (PC), and Halostachys capsica (HC), under moderate, heavy, and severe saline-alkaline conditions. Halophytes were then analysed via 16S amplicon sequencing. The relationships between soil physicochemical characteristics and bacterial diversity were determined via redundancy analysis (RDA) and Spearman correlation analysis. Results: As the saline-alkali levels increased, the bacterial richness and diversity decreased in the PC and HS groups but were greater in the severe grade than in the heavy grade in the HC group. The bacterial communities in the PC, HS, and HC treatments at different saline-alkali levels were significantly different. Moreover, the rhizosphere bacterial communities were sensitive to changes in the saline-alkaline environment. Proteobacteria, Actinobacteriota, Bacteroidota, and Halobacterota were the predominant phyla for PC, HS, and SC in moderate, heavy, and severe saline-alkaline soils, respectively. EC and pH affected the richness and β diversity of the bacterial communities of all the assayed halophytes, regardless of the saline-alkaline level. Conclusion: Our findings suggested that rhizosphere bacterial communities may play a role in halophyte adaptation to saline-alkali land, as well as promoting plant growth and improving ecological performance. [ABSTRACT FROM AUTHOR]

Coypu (Myocastor coypus) was recognized as ecological engineer for its ability to alter wet habitats and build structures throughout its life cycle. Platforms still represent poorly studied structures built by this rodent for various purposes, including reproduction, resting and thermoregulation. In order to obtain data on plant composition, size and density on the territory of coypu's platforms, we carried out a study in a Mediterranean wetland reed bed, stratifying data on two sub-habitat types (back dune and canal banks). Platforms were composed exclusively of common reed (Phragmites australis) stems, leaves, and inflorescences; they were elliptical in shape, and significantly higher in the back dune than on the canal banks. Density of platforms was higher in the back dune than on the canal banks. Platforms have been used as resting and feeding sites, as showed by drone images and remnants of red swamp crayfish (Procambarus clarkii). More than 40% of coypu's platforms along the canal banks showed traces of birds, suggesting an opportunistic use by waterfowls and waders. In this regard, platforms may be considered "key structures", locally increasing habitat heterogeneity. In a limited number of back dune platforms, remnants of plastic litter have been detected. The use of drone flights over wetlands may be useful to check the spatial pattern of coypu's platforms, especially in hard-to-reach areas. Ecological and management implications of our data have been reported. [ABSTRACT FROM AUTHOR]

Carbon emissions and environmental concerns have led to the aspiration to reduce peat extraction and its use as a growing medium (GM). In Nordic Forest tree seedling production, Sphagnum peat has been almost exclusively used as a GM in seedling containers due to its good properties and availability. This study examined the feasibility of several peat-reduced and peat-free GM in container tree seedling production of the key tree species in Nordic forestry (Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) as well as Russian larch (Larix archangelica P. Lawson & C. Lawson ex Trautv.) and common alder (Alnus glutinosa (L.) Gaertn.). Pure or mixed GM, consisting of low-humified Sphagnum peat (pure as a control), harvested Sphagnum moss, wood fiber, cow manure digestate from a biogas plant, and a common reed compost were tested. Seedlings were grown in controlled conditions in greenhouse experiments and also in larger-scale commercial tree nurseries. Peat-reduced media containing peat of at least 50 vol% provided growth that is similar to pure Sphagnum peat for the tested species and container types. All the studied alternative media can yield marketable seedlings, although commonly of reduced size and requiring special adjustments in growing management. The studied media have a potential to reduce or replace peat in seedling production, but adjustments of their physical and chemical properties, as well as of seedling fertigation and management procedures, are required. The economic feasibility and environmental sustainability of these GM, as well as the outplanting success of seedlings grown in these media, remain to be studied. [ABSTRACT FROM AUTHOR]

Biological invasions pose a significant threat to ecosystems, disrupting local biodiversity and ecosystem functions. The genomic underpinnings of invasiveness, however, are still largely unknown, making it difficult to predict and manage invasive species effectively. The common reed (Phragmites australis) is a dominant grass species in wetland ecosystems and has become particularly invasive when transferred from Europe to North America. Here, we present a high-quality gap-free, telomere-to-telomere genome assembly of Phragmites australis consisting of 24 pseudochromosomes and a B chromosome. Fully phased subgenomes demonstrated considerable subgenome dominance and revealed the divergence of diploid progenitors approximately 30.9 million years ago. Comparative genomics using chromosome-level scaffolds for three other lineages and a previously published draft genome assembly of an invasive lineage revealed that gene family expansions in the form of tandem duplications may have contributed to the invasiveness of the lineage. This study sheds light on the genome evolution of Arundinoideae grasses and suggests that genetic drivers, such as gene family expansions and tandem duplications, may underly the processes of biological invasion in plants. These findings provide a crucial step toward understanding and managing the genetic basis of invasiveness in plant species. We provide a complete, telomere to telomere gap-free genome assembly for common reed that includes its B chromosome. Comparative genomic analysis revealed that tandem duplications may have contributed to the invasiveness potential of the species. [ABSTRACT FROM AUTHOR]

This study aimed to assess the current water quality status across various regions within the Fayoum depression by examining water canals, drains, and potential contaminants impacting public health and the local ecosystem. Additionally, an adsorption treatability investigation was conducted on various antibiotics identified during the assessment. Fifteen sampling points were selected across the Fayoum depression, covering surface water bodies and agricultural drainage systems during both winter and summer seasons. Physico-chemical, microbiological, and antibiotic analyses were performed on collected water samples. The water quality parameters investigated included pH, electrical conductivity, total dissolved solids (TDS), total coliforms, fecal coliforms, and concentrations of antibiotics such as ciprofloxacin and tetracycline. The findings revealed significant variations in water quality parameters among different water sources, categorizing them into three types: irrigation canals, polluted canals, and drains. High contamination levels were observed in certain water canals and drains due to untreated sewage and agricultural drainage discharge. Notably, elevated TDS levels (exceeding 1200 mg/L), microbial indicators count (with total coliforms reaching up to 2.3 × 106 CFU/100 mL), and antibiotics (with concentrations of ciprofloxacin and tetracycline exceeding 4.6 µg/L) were detected. To mitigate antibiotic contamination, a Phyto-adsorption treatability study using magnetite nanoparticles prepared with Phragmites australis plant extract demonstrated promising results, achieving complete removal of high antibiotic concentrations with an adsorption capacity of up to 67 mg/g. This study provides updated insights into water quality in the Fayoum depression and proposes a novel approach for addressing antibiotic contamination, potentially safeguarding human and environmental health. [ABSTRACT FROM AUTHOR]

Sludge treatment reed bed planted (STRB) with Phragmites australis (P.australis) and Arundo donax (A.donax) was assessed in the presence of Eisenia fetida under control condition during the dry season. Worm-planted units were fed with mixed sewage sludge (dry and volatile solids of 29.44 g DS.L−1 and 24.23 g VS.L−1). Sludge loading rates (SLR) of 50, 60, and 70 kg DS m−2 year−1 were examined to assess dewatering efficiency. Surface layers in units with P.australis and A.donax achieved DS of 80 and 81% at a loading rate of 50 kg DS m−2 year−1, while their subsurface DS were 41 and 25%, respectively. Units with A.donax experienced plant loss when subjected to SLR exceeding 60 kg DS m−2 year−1. More than 10 cm of residual sludge accumulated on the top of units after a 2-month final rest. Evapotranspiration was greater in the unit with P.australis (5.23 mm day−1) compared to the unit with A.donax (4.24 mm day−1) while both were fed with 70 kg DS m−2 year−1. Water loss contributions from residual sludge layer, drained water, and evapotranspiration were 3, 46, and 51%, respectively. Units with P.australis indicated 20% higher water loss compared to units with A.donax. Although the drained water quality improved over time, it did not meet standard limits. The residual sludge layer contained macro and micronutrients, and heavy metals with a significant elemental order of N > Ca > P > S > mg > K (N:P:K = 31:8:1), Fe > Na > B > Mn > Mo and Zn > Cr > Cu > Pb > Ni > Cd. Overall, STRB could be a sustainable alternative technology to conventional sewage sludge management techniques. [ABSTRACT FROM AUTHOR]

Industrial effluents pose a serious environmental problem, because they contain toxic contaminants mainly heavy metals that are the most dangerous to humans, animals, plants, and the environment in general. Phytoremediation using macrophytes is an adopted technique for the environment decontamination due to its efficiency and cost-effectiveness. The present study aims to highlight the capabilities of macrophytes to remove heavy metals from wastewater of Biskra region (Algeria). The methodology consists of filling out the filters planted with Arundo donax and Phragmites australis with raw industrial wastewater, then recovering decontaminated water after 15 days to assess removal of lead, copper, zinc, and iron. Both plants had shown a good efficiency for the removal of metals loaded in wastewater eliminating about 94 to 98% of initial concentration. In addition, calculated bioaccumulation factor (BAF) had confirmed the accumulation of heavy metals in different parts of experimental plants; recorded values of BAF > 1 allowed the consideration of Arundo donax and Phragmites australis as good hyper-accumulator plants. Obtained results confirm the efficiency of phytoremediation technology using macrophytes for the wastewater treatment in particular and the environment decontamination in general. [ABSTRACT FROM AUTHOR]

Phragmites australis is one of the most invasive wetland plants on the planet with both native and invasive haplotypes occurring in the United States. Three Phragmites haplotypes (Delta-, EU- and Gulf-types) co-occur in marshes of the Mississippi River Delta (MRD), where a recent dieback of Phragmites has prompted investigations about the potential for recolonization by seed. In other areas of the US, the invasive EU-type has been shown to spread by seed, yet little is known about reproduction modes of the Delta- and Gulf-types. We conducted a survey at 35 sites along the Mississippi River Delta region in southeast Louisiana to examine the potential for sexual reproduction across haplotypes as well as the potential for hybridization. Seed and pollen samples were collected from Phragmites populations to examine flowering phenology and determine pollen viability of the three lineages. We also conducted a seedbank assay in stands of three haplotypes to test the potential for recruitment by seed. Despite the observed potential for sexual reproduction in Delta- and EU- types, no Phragmites seedlings germinated from the seedbank. EU was the only haplotype to exhibit germination from seeds collected from seed heads. Both spatial separation and temporal isolation in flowering times indicate that hybridization between Phragmites haplotypes in the lower MRD is unlikely. High pollen production, increased pollen production following dieback, and viable seeds in the EU-type suggest that this invasive haplotype has a greater potential to invade new areas and adapt to stressors through sexual reproduction compared to than Delta-or Gulf haplotypes. [ABSTRACT FROM AUTHOR]

The impact of climate warming on the decomposition of wetland plant litter has received widespread attention. We used the litter bag method to compare and study the decomposition processes of three species of litter in the Nansi Lake wetland of China, Phragmites australis (Ph), Nelumbo nucifera (Ne) and Typha domingensis (Ty), and simulate the changes in the decomposition characteristics of litter and the structure of the fungal community under atmospheric warming (2.0 ± 0.5 °C ~ 4.0 ± 0.5 °C) using open-top chambers (OTCs). The results showed that increasing temperature significantly accelerated the decomposition process of the three species of litter and increased the beta and alpha diversities of the fungal communities at the class level. The fungal community co-occurrence network showed that the fungal community network associated with litter decomposition under warming conditions consisted mainly of symbiotic relationships, and the order of the average clustering coefficients of the three networks was 2.0 ± 0.5 °C (0.81) > 4.0 ± 0.5 °C (0.77) > control (0.57). Moderate warming increased the degree of positive correlation and clustering between fungi, thus accelerating the decomposition process of plant litter and affecting the carbon balance of wetland ecosystems. [ABSTRACT FROM AUTHOR]

Phragmites australis is a common helophyte, covering much of the sheltered and shallow soft bottoms along the coasts of the Baltic Sea. Despite the expansion of P. australis over the past decades, there is little information on aquatic macroinvertebrates within P. australis beds. In this study, we examined the effect of large-scale (wave exposure, nutrients) and small-scale (distance from the seaward edge, live and dead stalk density, epiphyte and rhizome biomass) drivers on the density, taxa richness, diversity, and community structure of epifauna and infauna in monospecific P. australis beds around the Åland Islands and the Archipelago Sea. We found that higher wave exposure and nutrient levels generally supported higher epi- and infauna abundance and taxa richness. The effects on Shannon–Wiener diversity were less evident apart from an increase of the infauna diversity in the Archipelago Sea with increasing nutrient levels. On a local scale, the distance from the seaward edge, live and dead stalk density, and epiphyte biomass had varying effects on both epi- and infauna communities in the different regions. Rhizome biomass had no effect on either the epi- or infauna abundance, taxa richness, or diversity. Furthermore, according to existing studies, other habitats, e.g., Zostera marina meadows, Fucus vesiculosus belts, and vegetated soft-bottomed shallow bays, are generally characterized by more abundant fauna, except for the infauna, which had a higher density in P. australis beds than in vegetated soft-bottomed shallow bays. P. australis are a widespread, expanding, and understudied habitat with an important role in supporting coastal biodiversity. [ABSTRACT FROM AUTHOR]

A novel mesoporous magnetic biochar (MBC) was prepared, using a randomly growing plant, i.e., common reed, as an exporter of carbon, and applied for removal of methylene blue (MB) from aqueous solutions. The prepared sorbent was characterized by nitrogen adsorption/desorption isotherm, saturation magnetization, pH of point of zero charges (pHPZC), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The obtained MBC has a specific surface area of 94.2 m2 g−1 and a pore radius of 4.1 nm, a pore volume of 0.252 cm3 g−1, a saturation magnetization of 0.786 emu g−1, and a pHPZC of 6.2. Batch adsorption experiments were used to study the impact of the physicochemical factors involved in the adsorption process. The findings revealed that MB removal by MBC was achieved optimally at pH 8.0, sorbent dosage of 1.0 g L−1, and contact time of 30 min. At these conditions, the maximum adsorption was 353.4 mg g−1. Furthermore, the adsorption isotherm indicated that the Langmuir pattern matched well with the experimental data, compared to the Freindlich model. The ∆G was − 6.7, − 7.1, and − 7.5 kJ mol−1, at 298, 308, and 318 K, respectively, indicating a spontaneous process. The values of ∆H and ∆S were 5.71 kJ mol−1 and 41.6 J mol−1 K−1, respectively, suggesting endothermic and the interaction between MB and MBC is van der Waals type. The absorbent was regenerated and reused for four cycles after elution with 0.1 mol L−1 of HCl. This study concluded that the magnetic biochar generated from common reed has tremendous promise in the practical use of removing MB from wastewater. [ABSTRACT FROM AUTHOR]

A series of batch assays have been conducted to investigate the optimal factors that can be adopted to improve the anaerobic digestion (AD) performance of Phragmites australis and increase biogas production. The assays were carried out using 125 mL microcosm reactors with a working volume of 80 mL and incubated at mesophilic conditions (37 ± 1ºC). The effect of particle size (10, 5, 2, and < 1 mm) and alkaline pre-treatment of P. australis using various concentrations of sodium hydroxide (0.5, 1, 2, and 4%) on biogas production was examined. Furthermore, the best pre-treatment incubation time (12, 24, 48, 72, 96, and 120 h) and the optimal inoculum to substrate ratio (ISR: 4:1, 2:1, 1:1, 1:2 and 1:4) were also assessed. The results revealed that the highest biogas production from P. australis was achieved at particle size < 1 mm (27.97 ± 0.07 and 16.67 ± 0.09 mL/g VS added, for pre-treated and untreated P. australis respectively); 2% and 4% NaOH concentration for pre-treatment (70.01 ± 3.75 and 76.14 ± 2.62 mL/g VS added, respectively); pre-treatment incubation time of 72, 96, and 120 h (71.18 ± 1.79, 72.46 ± 1.08, and 73.78 ± 1.87 mL/g VS added, respectively); and ISR of 1:2 for pre-treated P. australis (78.21 ± 0.36 mL/g VS added) and ISR 1:4 for untreated P. australis (28.93 ± 1.55 mL/g VS added). Determining optimal parameters in this work would guide further development of process configurations, such as continuous AD systems. [ABSTRACT FROM AUTHOR]

This study focused on determining the effect of the inoculum to substrate ratio (ISR) on biogas production efficiency from the anaerobic co-digestion of two substrates: synthetic food waste and common reeds (Phragmites australis) that were ground and pre-treated using sodium hydroxide at a concentration of 2% to increase access to their cellulose. It also studied the role of different mixing ratios of the two substrates in improving the stability of the digestion process and increasing biogas production. A series of batch tests were carried out under mesophilic conditions using three ratios of ISR: 1:4, 1:2, and 1:1, and five substrate mixing ratios (synthetic food waste: pre-treated P. australis): 25:75, 50:50, 75:25, 100:0, and 0:100. The results showed low biogas production at the ISR 1:4 (21.58±0.00–44.46±0.01 mL/g volatile solid (VS) added), and the reactors suffered from acidification at the different substrates mixing ratios, while the biogas production increased at an ISR of 1:2, where the reactors with the substrate mixing ratio of 25:75 presented the highest biogas production (82.17±0.62 mL/g VS added), and the digestion process was stable. However, the reactors with substrate mixing ratios of 50:50, 75:25, and 100:0 suffered from acidification effects at this ISR. In contrast, at ISR of 1:1, the reactors did not expose to acidification inhibition at all the substrates mixing ratios, and the highest biogas production was found at synthetic food waste: pre-treated P. australis mixing ratios of 75:25 and 100:0 (76.15±1.85 and 82.47±1.85 mL/g VS added, respectively). [ABSTRACT FROM AUTHOR]

Aims: Lakeshore wetlands are global carbon (C) hotspots, but their role in C sequestration has been largely overlooked. The rhizosphere has a complex interaction of microbiota and metabolites, which plays an important role in wetland C cycling. This study aims to understand how the rhizospheric interactions affect harvested aboveground C and soil C of lakeshore wetlands in a subtropical region. Methods: An investigation of five lakeshore reed (Phragmites australis) wetlands at the similar latitudes of the Lower Yangtse Valley in China was carried out to explore the relationship of rhizospheric interactions with harvested aboveground C and soil C. The plant traits and soil physicochemical properties were determined due to their important role in affecting rhizosphere interactions. Results: Plant traits and soil physicochemical properties significantly differed among the sites, while aboveground C fixation did not significantly differ. The soil organic C (SOC) content of the topsoil was accounting for the majority of the soil total C at most sites, except for the wetland at the Yangtze River estuary with higher soil pH and conductivity, whose soil inorganic C (SIC) accounted for almost half. Bacterial community and metabolite composition were significantly partitioned across the region. Structural equation modeling revealed the rhizospheric interactions positively affected aboveground C and SOC, but negatively affected SIC. Their effects on soil C content were stronger than those on aboveground C fixation. Conclusions: The rhizosphere exhibited the direct and indirect effects on harvested aboveground C and soil C by altering microbial community structure and metabolite composition. [ABSTRACT FROM AUTHOR]

Carbon quantum dots (CQDs) and Nitrogen-doped CQDs (N-CQDs) were synthesized through a one-step hydrothermal process, utilizing reed leaves and urea as carbon and nitrogen sources, respectively. The maximum excitation wavelength of CQDs and N2-CQDs was 325 nm, and the corresponding emission wavelength was 407 nm and 406 nm, respectively. Synthetic CQDs have excellent fluorescence properties, while N-doping enhances the fluorescence intensity and stability of CQDs. Next, the adsorption effect of N2-CQDs on various metal ions was also studied using the fluorescence quenching method. The results showed that N2-CQDs have a significant capacity for adsorption of Cu2+ ions. The following quantitative analysis indicated that the Cu2+ concentration showed an excellent linear relationship between 0~500 μmol/L and the limit of detection (LOD) was 0.074 μmol/L. The N2-CQDs at 0-200 μg/mL have no deleterious effects on the viability of HeLa cells and the survival rate of Artemia nauplii. Finally, the agarose gel containing N2-CQDs was constructed, and its absorption behavior of Cu2+ in artificial seawater was evaluated. The results showed that this N2-CQDs-based gel was able to efficiently remove Cu2+ from seawater, leading to a higher survival rate of the nauplii under 10 and 50 mg/L Cu2+ stress. Our results collectively provide a cost-effective method for removing heavy metal ions from seawater and mitigating their harmful effects on sea animals. [ABSTRACT FROM AUTHOR]

Spartina anglica, an invasive marsh grass, was designated as a harmful marine organism in 2016 due to its ability to stabilize mudflats and reduce macrobenthic diversity. To control such invasive species, physical, chemical, or biological methods can be applied while chemical methods are prohibited by law due to ecological disruption. However, the preferred methods of soil tillage, cutting, and native plant restoration for managing S. anglica have rarely been analyzed. To compare the methods, we performed 9 treatments with four replicates, comprising control, different frequencies of clipping (once and twice) and tilling (once and twice), and different densities (50 and 100 seedling) of restoration of the native plants Suaeda japonica and Phragmites australis. To evaluate the severity of disturbance, we measured coverage, stem density, average plant height, and above-ground biomass for 2 years. We found P. australis and S. japonica did not successfully establish or survive due to niche differences and the inherent biological features of Spartina. However, physical removal had a stronger effect than interspecific interaction. Two cutting treatments in the early and the late growing season reduced plant height and biomass of S. anglica by 6 and 34%, respectively, compared with the control treatment at the rapid vegetative growth stage in the following year. We also found that two tillage treatments reduced biomass, plant cover, and stem density by 32%, 38%, and 83%, respectively, in the following year. In the study site, managing invasive species such as S. anglica is best achieved by physically destroying the plant using soil tillage while attempting to restore native species had marginal control effects. [ABSTRACT FROM AUTHOR]

Complete eradication of invasive plants is often infeasible but in some cases it is possible to reduce the invader to low levels with reduced ongoing management costs, referred to as functional eradication. Non-native Phragmites australis has challenged land managers across North America but functional eradication may yet be possible in some scenarios. Here we present data from Chesapeake Bay brackish tidal wetlands where two approaches to Phragmites management (long-term, continuous management and short-term, non-continuous management) were used. We demonstrate that the application of herbicides will lead to the establishment of native species, but long-term, continuous management is required to facilitate functional eradication of Phragmites by keeping it at low levels of occurrence and restoring native plant communities. Ultimately, historical data from sites that were sampled as part of this study indicate that if management is successful and results in functional eradication of Phragmites, then the recovering vegetation will include native species that were present before the sites were invaded by Phragmites. [ABSTRACT FROM AUTHOR]

Bioenergy is a proposed solution to anthropogenic greenhouse gas emissions. A sustainable deployment will require targeting marginal lands, particularly brownfield and/or degraded lands. Industrial remediation, however, is often uneconomical or even desirable, especially if degraded lands passively return to a nature like state. Degraded lands suitable for remediation include cement kiln dust landfills, containing saline solids. Phytoremediation uses plants to transport pollutants from the soil into standing biomass. After harvest, the biomass, here Phragmites australis, can be processed to separate salt, biomass and process water. Work showed that salt recovery was preferential for large liquid to solid ratios (10x) over longer durations and/or higher temperatures. Elevated temperatures require additional energy while co-leaching more biomass (~ 4 wt%). Repeated soaking with smaller volumes of room temperature water did not single, large volume soaks. A three-stage multi-stage soaking method produced a similar recovery (< 1.5 wt% salt) while consuming 20% less water. A modelled process produces biomass with sufficient energy density for use in the cement kiln at a fuel cost of $3.83/GJ, parity at a carbon price of $42 USD/t CO2. Remediation of cement kiln dust stockpiles is on the century time scale while co-producing biofuel for the plant would be annual. Each square kilometer planted could displace 4% of the fuel energy while returning the waste to the kiln. This represents an early opportunity for combined remediation, waste valorization and bioenergy. [ABSTRACT FROM AUTHOR]

Reed beds can be managed for commercial or conservation purposes, with effects on its inhabitants. In this paper, we assess the effect of management on the reed bed Coleoptera community by investigating reed beds subject to winter cutting, winter harvest, short-term unmanaged (3 years), and long-term unmanaged (25 years). Using pit fall traps, we collected Coleoptera across a summer season to estimate Coleoptera biomass, abundance, size, richness, diversity, and community composition across the four types of management of reed beds. Cutting and harvest both show to increase Coleoptera biomass compared to unmanaged reed beds, with the highest Coleoptera abundance found in the harvested reed bed. The species richness and diversity, on the other hand, peaked in the long-term unmanaged reed bed. Community composition differed between the different management types, and across time. Species of conservation concern were most abundant in recently managed areas. These results have implications for the conservation of the reed bed Coleoptera community. First, to maintain a high Coleoptera diversity, some areas must be left unmanaged. Secondly, to secure habitats for species of conservation concern as well as boost the Coleoptera biomass, frequent management of other areas is advised. This mosaic management pattern will also create the overall most species rich reed bed, as unique Coleoptera communities were found in each management type. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Heavy metals removal from industrial wastewater of Biskra (Algeria) by Arundo donax and Phragmites australis" published in the journal Environmental Monitoring & Assessment. The correction addresses errors in the placement and labeling of figures in the article. The corrected captions for Figure 3 and Figure 4 are provided, and it is noted that Figure 5 was missing from the original publication. The correction notice is authored by Sarra Badache and Nora Seghairi and published by Springer Nature. [Extracted from the article]

The present study was aimed to evaluate the potential of Arundo donax (giant reed) and Cynodon dactylon (grass clippings) biomasses as possible sources of fermentable sugars for microbial protein production by Candida tropicalis. Optimization of dilute acid pretreatment and detoxification parameters was carried out for selecting the best conditions for sugar release and efficient removal of inhibitory compounds. The optimum conditions for hydrolysis in both the biomasses were found to be 1.5% sulphuric acid, 1.5:10 solid to liquid ratio with 30 and 45 min duration for grass clippings and giant reed, respectively. Under these conditions, 21.85 g/L fermentable sugars including glucose and xylose were released from giant reed and 32.38 g/L from grass clippings in the dilute acid hydrolysate. Optimization of activated carbon-based detoxification revealed that 4% w/v activated charcoal concentration at pH 1.5 with 30 min orbital shaking was sufficient to achieve maximum reduction of inhibitors in giant reed hydrolysate. Whereas for grass clippings, 1 h treatment was required for significant reduction of phenolic compounds. The wild C. tropicalis was adapted for multiple generations to tolerate up to 14 g/L acetic acid in pure glucose and xylose based-medium. This adapted yeast when cultivated in concentrated hydrolysate media resulted in increase of cell biomass by 21.83 and 14.28% in giant reed and grass clippings, respectively in comparison to the wild yeast. The freeze-dried powder of C. tropicalis cells cultivated in giant reed and grass clippings hydrolysate contained 48.51% and 51.67% protein respectively. The results of this study advocate the potential of giant reed and grass clippings as efficient lignocellulosic sources for single cell protein production by C. tropicalis. [ABSTRACT FROM AUTHOR]

Background and Aims: Estuarine wetlands are important carbon sinks, with plant photosynthesis being a vital component of this process. Changes in the inundation depth of wetlands could alter leaf photosynthesis and thus ecosystem carbon uptake capacity, ultimately determining the size of carbon sink. However, the relationship between inundation depth and photosynthetic capacity has yet to be determined, especially in estuarine wetlands with complex hydrological conditions. In addition, there is also conflicting evidence regarding the effect of inundation depth on photosynthetic capacity. Methods: To better understand the mechanisms of photosynthetic capacity responding to inundation depth, we performed a field experiment with a gradient of inundation depths (0, 5, 10, 20, 30 and 40 cm) in estuarine wetland dominated by Phragmites australis in the Yellow River Delta, China. Results: Our results showed that inundation depth significantly altered leaf morphological traits, elements and photosynthetic capacity. In particular, leaf photosynthetic capacity was obviously increased with increasing inundation depth. The increased leaf area enhanced light harvesting ability of leaves, and then increased Pn at different inundation depths. Besides, higher leaf N content promoted leaf photosynthetic capacity at different inundation depths. Conclusion: Overall, the findings demonstrated that inundation depth significantly enhanced the photosynthetic capacity of P. australis, which was correlated with altered leaf functional traits in wetlands. Our results hold important implications for more accurately predicting the relationship between photosynthetic capacity and inundation depth in wetland ecosystems under climate change and more accurately estimating of the carbon sink capacity of wetland ecosystems in the future. [ABSTRACT FROM AUTHOR]

The accelerated eutrophication rate of (sub)tropical lakes is a major environmental problem. Constructed wetlands are considered as an effective method to purify water bodies. However, the removal rate of nitrogen (N), phosphorus (P) and other nutrients by wetland vegetation is quite different, and the continuous observation of plants and water ecosystems is required. In this study, the growth curves of two subtropical wetland plants, Phragmites australis and Zizania caduciflora, and their absorption effects on N and P in constructed wetlands were studied. The results showed that the growth curves of the two wetland plants were similar, reaching the biomass peak in July to August, and the cumulative absorption of N and P by plants had the same trend with the change of biomass. The N and P concentration of plants reached the peak in March to April, with higher concentration in Phragmites australis than that of Zizania caduciflora. At the end of the growing season, i.e. around October 20, the accumulated absorption of N and P by plants reached the maximum, which was the optimal time for harvest of subtropical wetland plants. Thereafter, the residues of plant litter entered the water, causing the recovery of N and P concentration in the water body, therefore affected the purification function of wetland. There is a strong correlation between the water purification efficiency and plant growth. With the increase of biomass, N and P accumulation in Phragmites australis and Zizania caduciflora, the N, P content and chemical oxygen demand (COD) in the water of wetland showed a significant decreasing trend. The removal rates of N, P, COD and suspended substance (SS) in the constructed wetlands with Phragmites australis and Zizania caduciflora as the main plants were 95%, 96%, 82% and 86%, respectively. In general, the purification capacity of Phragmites australis is slightly higher than that of Zizania caduciflora and precipitation had positive effects on the pollutants concentration of wetland water. The results provide scientific basis for plant selection and management of subtropical constructed wetlands. [ABSTRACT FROM AUTHOR]

In the effort to identify sustainable sludge management options, pilot-scale sludge treatment reed beds (STRBs) were tested and assessed in the Sultanate of Oman in the first integrated experimental study of this nature-based solution in the Middle East region. A total of 18 pilot STRB units were established and monitored for almost 2 years; half were planted with native Phragmites australis reed species, and half served as unplanted control units. Employing a randomized complete block design, the study examined varying sludge loading rates (SLR) of 75, 100, and 125 kg/m2/year. Results underscored the effectiveness of STRBs in reducing the sludge volume, with observed reductions reaching 98.0% of the applied sludge volume, particularly prominent in the SLR75 units. During the final resting phase, the STRBs showed slightly higher concentrations of total Kjeldahl nitrogen (TKN) and total phosphorus (TP) compared to the unplanted beds, while maintaining concentrations lower than those of the applied activated sludge. Furthermore, heavy metal concentrations were consistently diminished in the STRBs compared to the unplanted beds, aligning with the established national and international standards for sludge reuse in agricultural contexts. The results of this study provide the first valuable insight into the potential of STRBs as an effective, sustainable, and climatically suitable approach for sludge dewatering. Specifically, an SLR of 100 kg/m2/year is proposed as an optimum loading rate for the hot and arid Middle East climate. This study advances our understanding of STRBs as a pivotal component in the realm of arid-region sludge treatment, shedding light on their capacity to facilitate enhanced dewatering, mineralization, and nutrient removal, thereby contributing to the broader discourse on sustainable waste management practices. [ABSTRACT FROM AUTHOR]

The decomposition of standing litter is a vital but easily neglected process. Most studies always focused on the decomposition of leaf litter on the surface of soil or sediment, whereas the decomposition of leaf and non-leaf litter in the air is often overlooked. A field experiment was conducted in the Yellow River Delta to investigate the decomposition of leaf and non-leaf (culm and sheath) litter (Phragmites australis) in the air and on the ground. The results showed that the litter on the ground decomposed faster than the standing litter due to its larger enzyme activities, and the remaining mass of litter on the soil surface was 73–87% of the standing litter. The culm litter had the largest mass remaining among three types of litter owing to the lowest enzyme activities and the largest initial C/N and C/P of the culm litter. Concerning the dynamics of nutrient, nitrogen and phosphorus in leaf and non-leaf litter were first released and then enriched at two decomposition interfaces. Of the three types of litter, the culm litter had the highest N remaining after 360 days of decomposition due to the largest initial C/N of the culm litter. Our findings emphasize the importance of standing litter decomposition in the wetlands of the Yellow River Delta, and suggest that the decomposition of non-leaf (culm and sheath) litter of emergent macrophytes should not be ignored in wetlands. [ABSTRACT FROM AUTHOR]

Background: The study of soil organic carbon characteristics and its relationship with soil environment and vegetation types is of great significance to the evaluation of soil carbon sink provided by inland salt marshes. This paper reports the characteristics of soil organic carbon fractions in 0–50 cm soil layers at four vegetation communities of the Qinwangchuan salt marsh. Results: (1) The soil organic carbon content of Phragmites australis community (9.60 ± 0.32 g/kg) was found to be higher than that of Salicornia europae (7.75 ± 0.18 g/kg) and Tamarix ramosissima (4.96 ± 0.18 g/kg) and Suaeda corniculata community (4.55 ± 0.11 g/kg). (2) The soil dissolved organic carbon, particulate organic carbon and soil microbial biomass carbon in 0–50 cm soil layer of Phragmites australis community were higher, which were 0.46 ± 0.01 g/kg, 2.81 ± 0.06 g/kg and 0.31 ± 0.01 g/kg, respectively. (3) Soil organic carbon was positively correlated with dissolved organic carbon, particulate organic carbon, and microbial biomass carbon, and negatively correlated with easily oxidized organic carbon. (4) Above-ground biomass has a strong direct positive effect on soil organic carbon, total nitrogen and pH have a strong direct positive effect on microbial biomass carbon content, pH and average density have a strong direct negative effect on easily oxidized organic carbon, and particulate organic carbon. Conclusions: The interaction between plant community characteristics and soil factors is an important driving factor for soil organic carbon accumulation in inland salt marshes. [ABSTRACT FROM AUTHOR]

Background and aims: Coastal wetland types have been severely altered by human reclamation activities and Spartina alterniflora invasion. However, how these changes impact C-N-P stoichiometry and nutrient allocation of coastal plants remain unclear. Methods: We investigated C, N, and P contents and ratios in leaf, stem, and root from 30 sites with adjacent natural wetlands (as control, dominated by native Phragmites australis), reclaimed wetlands (dominated by native P. australis), and invasive wetlands (dominated by exotic S. alterniflora) across eastern coast of China. Results: C content and N:P ratio remained constant, N and P contents decreased significantly, but C:N and C:P ratios increased with increasing latitude in natural wetlands. While the direction or magnitude of these latitudinal patterns in reclaimed and invasive wetlands were extremely changed at both individual and organ level. Interestingly, leaf had significant higher C, N, and P contents but lower C:N and C:P ratios than stem and root in each wetland. Compared with natural wetlands, both reclaimed and invasive wetlands had significant lower C and N contents and N:P ratio but higher C:N ratio, invasive wetlands also had significant higher leaf P content. P. australis enhanced the homeostasis for N:P, strength allometric relationship of N and P in leaf, but exhibited a isometric relationship of N and P at individual level after reclamation. S. alterniflora had strict homeostasis for N, P and N:P in most organs and strong ability to decouple the allometric relationship of N and P in leaf, and N changed faster than P at individual level. Conclusions: Importantly, large-scale observations showed that reclamation and especially S. alterniflora invasion significantly decreased N:P ratio in each organ, which might highly affect below- and above-ground trophic chains in the future. Our study provides practical insights in understanding species-specific and multiorgan biogeochemical process and the nutrient allocation strategies of plants under reclaimed and invasive pressures in coastal salt marshes. [ABSTRACT FROM AUTHOR]

Historical land-use conversion and drainage may increase the risk of high intensity, soil-consuming fires in peatlands. Severe fires may degrade ecosystem resilience through changes in hydrology and by removing remnant seed and bud banks. Lower ecosystem resilience leaves peatlands highly susceptible to species invasions from aggressive colonizing vegetation post-disturbance. In this work we aimed to address the impacts of smoldering fires on the abundance of the noxious Phragmites australis in a large fire scar at the Great Dismal Swamp National Wildlife Refuge (VA and NC, USA). Primarily, we wanted to observe the extent of the relationship between the altered hydrology of post-fire conditions and P. australis occurrence. We did so by leveraging high resolution 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 findings emphasize the importance of hydrologic management post-disturbance for limiting P. australis invasion. Further, we highlight the potential for feedbacks between deep peat-consuming burns and P. australis invasions and spread in degraded peatlands. [ABSTRACT FROM AUTHOR]

The present investigation aims to explore the potential of chemical treatment to improve the acoustic and morphological performance of Arundo donax reed particles. To this end, both treated and untreated particles were fabricated into samples with varying diameters and subjected to sound absorption testing via a two-channel impedance tube. The findings revealed that the immersion of particles in a 5% sodium hydroxide solution resulted in a reduction in particle diameter by 19.2%, as well as an increase in inner surface porosity by 4.9%. Consequently, the sound absorption performance of treated particles improved by an average of 42.6% when compared to untreated particles. Notably, the impedance spectroscopy results indicated that the differences in the real and imaginary parts of the impedance can be attributed to a reduction in particle thickness and roughness of surface morphology after treatment with NaOH. Overall, these observations offer compelling evidence that chemical modification of natural fibers can lead to the development of more efficient and effective porous sound absorbers. [ABSTRACT FROM AUTHOR]

This project evaluated the potential of common reed to recover heavy metals as valuable products. Common reeds were grown in 25, 50, or 75 ppm Ni2+ and/or Cu2+ solutions for 4 weeks to evaluate its potential to uptake metals followed by converting the contaminated biomass to valuable products by hydrothermal conversion (HTC). The higher concentration of metals in solution, the more metals accumulated in plants. Most metals were sequestered in the roots of reeds. Roots and stems treated with binary metals contained less Ni2+/Cu2+ than those cultured in single metal. The yields of bio-oils and hydrochars from reeds treated with different levels of metals were similar. About 6–10% of the total biomass were transferred to bio-oil, while 50–60% of the biomass were produced as hydrochars. The results suggest that metal accumulated in reeds does not affect the utilization of contaminated reeds via HTC. About 0.1–1.5% of Cu2+ and/or Ni2+ absorbed in biomass were transmitted from contaminated reeds to bio-oils after HTC at 250 °C. [ABSTRACT FROM AUTHOR]

Developed areas of the coal industry are subjected to long-term anthropogenic impacts from the input and accumulation of overburdened coal material, containing potentially toxic heavy metals and metalloids (HMM). For the first time, comprehensive studies of soils and plants in the territory of the Donetsk coal basin were carried out using X-ray fluorescence, atomic absorption analysis, and electron microscopy. The observed changes in the soil redox conditions were characterized by a high sulfur content, and formations of new microphases of S-containing compounds: FeS2, PbFe6(SO4)4(OH)12, ZnSO4·nH2O, revealed the presence of technogenic salinization, increased Сorg content, and low pH contents. Exceedances of soil maximum permissible concentrations of Pb, Zn, Cu, and As in areas affected by coal dumps were apparent. As a consequence of long-term transformation of the environment with changes in properties and chemical pollution, a phytotoxic effect was revealed in Phragmites australis (Cav.) Trin. ex Steud, accompanied by changes in ultrastructural and organization features of roots and leaves such as increases in root diameters and thickness of leaf blades. The changes in the ultrastructure of cell organelles: a violation of the grana formation process, an increase in the number of plastoglobules, a decrease in the number of mitochondrial cristae, and a reduction in the electron density of the matrix in peroxisomes were also observed. The accumulation of large electron-dense inclusions and membrane fragments in cell vacuoles was observed. Such ultrastructural changes may indicate the existence of a P. australis ecotype due to its long-term adaptation to the disturbed environment. [ABSTRACT FROM AUTHOR]

Abstract—The results of investigations of the flora of small rivers within the city of Saratov (Elshanka, Nazarovka, Pervaya Gusel'ka, and Vtoraya Gusel'ka) are presented. The species composition of aquatic plants of the streams studied is represented by 37 macrophyte species belonging to 23 genera, 17 families, and three divisions (Charophyta, Polypodiophyta, and Magnoliophyta). The families Potamogetonaceae, Cyperaceae, and Lemnaceae predominate by the number of represented species. The values of the Menchinik index indicate that the greatest floristic diversity is characteristic of the Elshanka and Nazarovka rivers (3.1 and 3.4, respectively). The species composition of aquatic plants of the studied rivers within the urban area has a low similarity coefficient with the flora of rivers with relatively low anthropogenic load. Hydrophytes are the most numerous ecological group (22 species). According to the Paley–Kownacki dominance index, among the macrophytes of the rivers studied, most species are subdominant (57.28%) (Potamogeton perfoliatus, Typha angustifolia, Lemna trisulca, etc.); 37.18% (Phragmites australis, Potamogeton pectinatus, Lemna minor, Ceratophyllum demersum) belong to dominants, and the rest (11.54%) are defined as subdominants of the first order. Exceptional predominance is characteristic of Ceratophyllum demersum and Phragmites australis, which acted as dominants in all rivers studied. A significant part of the rivers is characterized by a low degree of overgrowth by hydrophilous vegetation, from slightly overgrown to not overgrown. The main types of distribution of aquatic and riparian-water vegetation are belted and fragmentary. Macrophyte communities are characterized by a simplified structure (one- or two-tiered), with absolute predominance of one plant species and the presence of two to four associated species with low values of projective coverage. The results of our calculations of indices (macrophyte index for small rivers (Sm), Indice Biologique Macrophytique in Riviere (IBMR)) based on the structural parameters of macrophytes showed that the rivers studied have a satisfactory ecological status. [ABSTRACT FROM AUTHOR]

Floating treatment wetlands (FTWs) are a sustainable solution to treat polluted water, but their role in chromium (Cr(III)) removal under neutral pH conditions remains poorly understood. This study evaluated the potential of FTWs planted with two perennial emergent macrophytes, Phragmites australis and Iris pseudacorus, to remove Cr(III) and nutrients (N and PO4-P) from water containing 7.5 mg/L TN, 1.8 mg/L PO4-P, and Cr(III) (500, 1000, and 2000 µg/L). Within 1 h of exposure, up to 96–99% of Cr was removed from the solution, indicating rapid precipitation. After 50 days, Phragmites bound 9–19% of added Cr, while Iris bound 5–22%. Both species accumulated Cr primarily in the roots (BCF > 1). Biomass production and growth development were inhibited in Cr treatments, but microscopic examination of plant roots revealed no histological changes at 500 and 1000 µg/L Cr, suggesting high resistance of the tested species. At 2000 µg/L Cr, both species exhibited disruptions in the arrangement of vessel elements in the stele and increased aerenchyma spaces in Phragmites. At the end of the experiment, 70–86% of TN and 54–90% of PO4-P were removed. [ABSTRACT FROM AUTHOR]

Background and aims: The introduced lineage of Phragmites australis (haplotype M) in North America outcompetes the native lineage (haplotype E). Previous studies have found that haplotype M is situated on the fast side of the trait economic spectrum compared to haplotype E in North America and Europe. The present study evaluated the plant traits and associated soil microbes of introduced and native Phragmites lineages using a common garden experiment. Methods: Four geographic groups, including the introduced lineage of North America (NAint, haplotype M), native lineage of North America (NAnat, haplotype E), European group (EU, haplotype M) and northwestern China group (CHN, haplotype M), were studied in two life-history stages – growing period and withering period. Results: No trait differences were observed among the four groups. The difference existed in the soil microbial structure. The soils derived from the four groups had different bacterial generic structures. NAnat gathered more plant pathogenic and ectomycorrhizal fungi in the growing period. In the withering period, NAint accumulated more plant pathogenic fungi, while NAnat accumulated more arbuscular mycorrhizal fungi. The soil microbial structure was different among NAint, EU and CHN despite the same haplotype. Conclusion: The interaction between plant traits and the soil microbes seemed weak. However, the long-term effects of microbial transition on the introduced and native lineages are unknown, and the potential plant-soil interactions need further exploration. [ABSTRACT FROM AUTHOR]

Invasion of Phragmites australis (common reed) in wetlands throughout North America, and particularly the Laurentian Great Lakes Basin, poses significant ecological problems. The extended period of low Great Lakes water levels from 2000 to 2013 created conditions for large expansions of Phragmites in the Great Lakes coastal zone. The following extended period of high water in the Great Lakes during late 2010's, culminating in record high lake levels in 2020 allowed managers to take advantage of high water by using a cut-to-drown management strategy (i.e., cutting plants below the water surface to stop the flow of atmospheric gases) to control Phragmites populations. To examine the efficacy of a cut-to-drown control strategy, we conducted a controlled-greenhouse study that tested the effect of submergence and timing of cutting (early or late in growing season) on Phragmites growth and viability post treatment. To evaluate Phragmites growth and viability, we measured belowground biomass, rhizome non-structural carbohydrate content (NSC), and rhizome viability following a cut-to-drown treatment. Applying a cut-to-drown treatment reduced average belowground biomass production up to 99%, limited rhizome NSC content up to 83%, and inhibited rhizome viability, regardless of timing of cutting treatments. These results suggest that under high-water conditions, utilizing a cut-to-drown strategy has potential for being a useful control mechanism for Phragmites. However, further research is needed to determine to what extent these results will lead to sustained reductions in growth and viability under field conditions, where rhizome belowground biomass and storage capacity are much larger. [ABSTRACT FROM AUTHOR]

Mangroves are coastal ecosystems dependent on saline water conditions, although freshwater is seasonally present in most types of mangroves. The riparian mangroves have a greater influence of freshwater than salty water, reducing saline stress and allowing greater productivity and diversity. As they are associated with freshwater channels, their hydrology makes them both a source and a sink for sediments, nutrients, and organic matter. The wetlands adjacent to riparian mangroves are mainly freshwater swamps or marshes. To monitor the composition and abundance of the vegetation and the production of litter and roots in the midterm, 27 monitoring units were monitored (22 in mangroves, five in wetlands) in two periods (2015–2016 and 2018–2019). In them, we evaluated biotic characteristics and root production annually, and monthly the litter production and pore and river water salinity. We detected a gradient of salinity spatially and temporally. The salinity gradually decreased as the distance to the river increased. In the winter of 2018–2019 saline intrusion increased the interstitial and river water values by an average of 10 (interstitial water) and 16‰, (river water). This increase caused a significant decrease in litter and root production and augmented the cover of Laguncularia racemosa (freshwater marsh), mortality of herbaceous species (Acrostichum danaeifolium, Typha domingensis, Phragmites australis), and tree species such as Annona glabra and Acoelorraphe wrightii. [ABSTRACT FROM AUTHOR]

This study which was carried out between July 2019 and April 2020 aimed to determine the seasonal changes of heavy metals (Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, and Zn) in plant organs of Phragmites australis and Typha angustifolia grown in Eğirdir Lake and to research the usability of the these plants for phytoremediation with the calculation of bioaccumulation factor (BF). Plant samples were brought to the laboratory, and then washed, cleaned with distilled water, dried in an oven at 70 °C and acidified with 10 ml HNO3. The samples were heated at 120 °C on a hot plate until completely mineralized. After mineralization, heavy metal concentrations were determined by using ICP-AES (Vista model). Only Mo was the highest in leaf, while other metals were highest in root in P. australis. In T. angustifolia, Mn and Mo were highest in the leaf, the accumulation of other metals was observed to be higher in the plant's roots than the other organs. It was discovered that the metal concentrations in root, in stem, and in leaf for both macrophytes generally increased in summer and decreased in root in autumn and winter and in stem and in leaf in spring for P. australis and in all organs in spring for T. angustifolia. Bioaccumulation factor (BF) values were calculated to determine the phytoremediation potential of P. australis and T. angustifolia. Both macrophytes are not excluder for all metals. Plants revealed potential for phytoremediation for the removal of heavy metals especially Mo and Zn. As a result of our study, it was determined that both macrophytes had accumulation abilities especially for Mo and Zn. It should be taken into consideration that these macrophytes can be used for improving the current situation of Eğirdir Lake due to their advantages such as being economical and not causing any harm to the environment. [ABSTRACT FROM AUTHOR]

Aims: Coastal salt marshes are productive ecosystems that are highly efficient carbon sinks, but there is uncertainty regarding the interactions among climate warming, plant species, and tidal restriction on C cycling. Methods: Open-top chambers (OTCs) were deployed at two coastal wetlands in Yancheng, China, where native Phragmites australis (Phragmites) and invasive Spartina alterniflora (Spartina) were dominant, respectively. Two study locations were set up in each area based on difference in tidal action. The OTCs achieved an increase of average daytime air temperature of ~ 1.11–1.55 °C. Net ecosystem CO2 exchange (NEE), ecosystem respiration (Reco), CH4 fluxes, aboveground biomass and other abiotic factors were monitored over three years. Results: Warming reduced the magnitude of the radiative balance of native Phragmites, which was determined to still be a consistent C sink. In contrast, warming or tidal flooding presumably transform the Spartina into a weak C source, because either warming-induced high salinity reduced the magnitude of NEE by 19% or flooding increased CH4 emissions by 789%. Remarkably, native Phragmites affected by tidal restrictions appeared to be a consistent C source with the radiative balance of 7.11–9.64 kg CO2-eq m–2 yr–1 because of a reduction in the magnitude of NEE and increase of CH4 fluxes. Conclusions: Tidal restrictions that disconnect the tidal hydrologic connection between the ocean and land may transform coastal wetlands from C sinks to C sources. This transformation may potentially be an even greater threat to coastal carbon sequestration than climate warming or invasive plant species in isolation. [ABSTRACT FROM AUTHOR]

Besides wood, the most widely used natural structural material, dicotyledonous fibre plants such as flax or hemp, and monocotyledonous grasses such as cereal straw or bamboo have been shown to be suitable for application in materials. Common reed is a less well-characterised plant resource in this regard. Therefore, common reed stems were characterised in uniaxial tension in the present study, aiming at acquiring basic information about the mechanical characteristics of this material. Furthermore, laboratory-scale composite beams were manufactured and tested in bending. Compared to wood species with similar density, common reed stem walls showed a comparable average modulus of elasticity of 8 GPa and a very good average tensile strength of 150 MPa. After a mild alkali pre-treatment, reed showed excellent adhesive bonding, enabling the manufacture of high-density composite beams with roughly 130 MPa bending strength and 12–13 GPa modulus of elasticity. Same as untreated common reed stem walls, also reed biocomposite beams compared very favourably with established wood-based materials of similar structure, density, and adhesive content. In summary, it was thus demonstrated that common reed is a highly suitable raw material for bio-based load-bearing structural materials. [ABSTRACT FROM AUTHOR]

Saltmarsh is a major contributor to global blue carbon (C) sink. However, plant invasion and anthropic activities have greatly altered its distribution and its blue C function in the last decades. We used remote sensing and data synthesis to investigate how the four decades of plant invasion and land reclamation affect the spatiotemporal variation of blue C in Yancheng saltmarshes, the largest coastal ecosystem in eastern China. We revealed that the invasion of exotic cordgrass, Spartina alterniflora, greatly increased the regional blue C storage, mainly by the seaward expansion of cordgrass in mudflats and its high ecosystem C stock. The iconic Suaeda salsa "Red Beach" marshes shrank by 90%, mainly due to reed occupation by the native reed, Phragmites australis. Phragmites australis marsh area was greatly occupied by reclamation, but well offset by its intrusion into Suaeda salsa. The blue C gain by cordgrass invasion overcompensated C loss due to land reclamation and the loss of "Red Beach". Our findings highlight that coastal blue C is greatly regulated by vegetation coverage, and the seaward cordgrass invasion can benefit the saltmarsh C sequestration. Such a similar process may apply in other regions of the world, with potentially large implications for blue C sinks. Highlights: •Spartina alterniflora marshes had high carbon sink capacity. • The spatiotemporal dynamics of plant cover in Yancheng saltmarshes were attributed to the Spartina alterniflora invasion into mudflats and anthropogenic activity. • The blue carbon gain by Spartina alterniflora invasion overcompensated carbon loss due to land reclamation and the loss of "Red Beach". [ABSTRACT FROM AUTHOR]

Litter decomposition is essential for carbon and nutrient cycling in wetland ecosystems. The management of Phragmites australis, a kind of widespread wetland emergent plant, is generally of great importance to the regulation of this biogeochemical cycle. In this study, we conducted a 210 days mesocosm experiment to examine the decomposition processes and return of elements carbon, nitrogen, and phosphorus in Phragmites litter under the influence of different detritus amount. Our results verified that in the range of 0–1,000 g/m2 of detritus amount of Phragmites litter, the decomposition of biomass, lignin, and cellulose of Phragmites litter was better correlated with the stoichiometric ratios in ambient water than in Phragmites litter itself. The detritus amount did not affect the decomposition of biomass, lignin, cellulose, or release of total phosphorous (TP) in Phragmites litter, but did affect the total organic carbon (TOC) and total nitrogen (TN). The overall decomposition rate and decomposition rates of lignin and cellulose of Phragmites in water varied between 0.001 and 0.004 per day. Therefore, the detritus amount of Phragmites litter after the typical harvesting method might affect the decomposition of Phragmites litter more by influencing water. This has a certain reference value to further research on wetland ecosystem management. [ABSTRACT FROM AUTHOR]

With continued anthropogenic inputs of nitrogen (N) into the environment, non-point source N pollutants produced in winter cannot be ignored. As the water-soil interface zones, riparian wetlands play important roles in intercepting and buffering N pollutants. However, winter has the antagonistic effect on the N removal. Substrate improvement has been suggested as a strategy to optimize wetland performance and there remain many uncertainties about the inner mechanism. This study explores the effects of substrate improvement on N removal in winter and rhizospheric crosstalk between reed (Phragmites australis) and microbes in subtropical riparian reed wetlands. The rates of wetland N removal in winter, root metabolite profiles, and rhizosphere soil microbial community compositions were determined following the addition of different substrates (gravel, gravel + biochar, ceramsite + biochar, and modified ceramsite + biochar) to natural riparian soil. The results showed that the addition of different substrates to initial soil enhanced N removal from the microcosms in winter. Gravel addition increased NH4+-N removal by 8.3% (P < 0.05). Gravel + biochar addition increased both TN and NH4+-N removals by 8.9% (P < 0.05). The root metabolite characteristics and microbial community compositions showed some variations under different substrate additions compared to the initial soil. The three treatments involving biochar addition decreased lipid metabolites and enhanced the contents and variety of carbon sources in rhizosphere soil, while modified ceramsite + biochar addition treatment had a greater impact on the microbial community structure. There was evidence for a complex crosstalk between plants and microbes in the rhizosphere, and some rhizosphere metabolites were seen to be significantly correlated with the bacterial composition of the rhizospheric microbial community. These results highlighted the importance of rhizospheric crosstalk in regulating winter N removal in riparian reed wetland, provided a scientific reference for the protection and restoration of riparian reed areas and the prevention and control of non-point source pollution. [ABSTRACT FROM AUTHOR]