Phragmites Australis Research Articles

Diversity Patterns and Drivers of Soil Bacterial and Fungal Communities in a Muddy Coastal Wetland of China

Elucidating the dynamics of soil microbial diversity in coastal wetlands is essential for understanding the changes in ecological functions within these ecosystems, particularly in the context of climate change and improper management practices. In this study, the diversity patterns and influencing factors of soil bacterial and fungal communities in a muddy coastal wetland in China were investigated using Illumina sequencing of 16S rRNA and ITS1, across wetlands dominated by different vegetations and varying proximity to the coastline. The wetlands include four plots dominated by Spartina alterniflora (SA1), four plots dominated by Suaeda glauca (SG2), additional four plots of Suaeda glauca (SG3), and four plots dominated by Phragmites australis (PA4), ranging from the nearest to the coast to those farther away. The results revealed significant differences in bacterial richness (Observed_species index) and fungal diversity (Shannon index) across different wetlands, with SG3 demonstrating the lowest bacterial Observed_species value (1430.05), while SA1 exhibited the highest fungal Shannon value (5.55) and PA4 showing the lowest fungal Shannon value (3.10). Soil bacterial and fungal community structures differed significantly across different wetlands. The contents of soil available phosphorus and total phosphorus were the main drivers for fungal Observed_species and Shannon index, respectively. Soil organic carbon, pH, and salinity were indicated as the best predictors of bacterial community structure, accounting for 28.1% of the total variation. The total nitrogen content and soil salinity contributed mostly to regulating fungal community structure across different wetlands, accounting for 19.4% of the total variation. The results of this study offer a thorough understanding of the response and variability in soil microbial diversity across the muddy coastal wetlands in China.

Removal of bisphenol A (BPA) from aqueous solution by potassium carbonate modified wetland plant biochars

Bisphenol A (BPA) is a known endocrine disruptor that is acutely toxic to the living organisms. In this study, the wetland plants Phragmites australis and Typha orientalis were subjected to carbonize at 500℃ for different durations (4, 5, and 6h) and varying mass ratios of wetland plants to potassium carbonate (1:2, 1:1, and 2:1). The prepared modified biochars were used to treat BPA in solution to explore the effect of contact time and initial concentration of BPA on adsorption performance. Both adsorption kinetic models and isotherm models were also studied. The results demonstrated a gradual increase in the adsorption capacity of Phragmites australis and Typha orientalis biochars for BPA with prolonged contact time. Furthermore, an enhancement in the adsorption capacity was observed with increasing initial BPA concentration. The modified biochars significantly enhanced BPA removal and adsorption capacities for BPA compared to the unmodified biochars. L55C (Phragmites australis carbonized at 500℃ for 5h with a mass ratio of 2:1) and X54C (Phragmites australis carbonized at 500 ℃ for 4h with a mass ratio of 2:1) exhibited the largest total surface areas, total pore volumes, microporous surface areas and microporous volumes, and achieved maximum adsorption capacities of 8.547 and 8.117mg/g, respectively. The adsorption processes were fitted with pseudo-second-order adsorption kinetic models and Langmuir models. The adsorption processes were monolayer chemical adsorption.

Quantitatively unveiling the role of coastal wetlands in regulating eutrophication and enhancing water environmental capacity

Human activities have intensified the global challenge of coastal eutrophication. Recently, water resource managers have encountered difficulties in formulating precise pollutant reduction strategies to mitigate coastal eutrophication. Despite the recognized importance of coastal wetlands and pollution sources in influencing coastal nutrient levels, accurately quantifying their impact remains difficult. To address this challenge, this study introduces a novel approach for optimizing water environmental capacity. A coupled model integrating hydrodynamics, water quality, and wetland nutrient mechanisms was developed to simulate the spatio-seasonal distribution of water, sediment, and vegetation nutrients in a semi-enclosed bay (Liaodong Bay, China) and a large-scale coastal wetland (Liaohe estuary wetland, China). Model parameters and simulation results were calibrated and validated using extensive long-term field investigations and laboratory experiments. The average root mean square errors between simulated and observed values for all validation points were as follows: 0.80mgL-1, 0.53mgL-1, 0.08mgL-1, 6.70μgL-1, and 0.50μgL-1 for dissolved oxygen, chemical oxygen demand, dissolved inorganic nitrogen, dissolved inorganic phosphorus, and chlorophyll-a, respectively. The total nitrogen (TN) and total phosphorus (TP) in the sediment were 0.10gkg-1 and 0.05gkg-1, respectively. For Suaeda salsa, the TN and TP were 2.91gkg -1 and 0.08gkg -1, respectively. For Phragmites australis, the TN and TP were 114.22gkg -1 and 6.21gkg -1, respectively. The results suggest that excessive river discharge and a stable residual circulation structure contribute to the persistent eutrophication in Liaodong Bay. The Liaohe estuary wetland enhances the environmental capacity of dissolved inorganic nitrogen and dissolved inorganic phosphorus in Liaodong Bay to 271±31tyr-1 and 8±1tyr-1, respectively, accounting for 1.8±0.2% and 1.3±0.2% of their respective environmental capacities. The reduction in dissolved inorganic nitrogen concentration is significant, with a maximum decrease of 0.17mgL-1. The maximum contributions of atmospheric deposition and aquaculture wastewater to dissolved inorganic nitrogen concentration are 0.08mgL-1 and 0.03mgL-1, respectively, with higher contributions in spring and summer than in fall and winter. These findings highlight the critical role of coastal wetlands in mitigating eutrophication and underscore the need for spatio-seasonal water management programs. This work serves as a model for effectively reducing global coastal pollution emissions.

GC-MS Analysis and Quantification of Some Secondary Metabolites of the Algerian Phragmites australis Leaf Extract and Their Biological Activities

GC-MS Analysis and Quantification of Some Secondary Metabolites of the Algerian Phragmites australis Leaf Extract and Their Biological Activities

Changing dominance of invasive Phragmites australis and native plant colonization with variation in management, wildfires, and soils in a desert wetland

Abstract Among the most widely distributed species globally, common reed (Phragmites australis (Cav.) Trin. ex Steud.) has generated extensive interest in invasive plant science and management because its introduced strains are highly invasive and often form monocultures that alter ecosystem properties. In desert wetlands in Las Vegas, Nevada, USA, where management goals included reducing hazardous P. australis fuels and increasing native plant diversity, we assessed variation in P. australis cover, the degree of native plant colonization, and soil seed banks after P. australis management treatments (cutting, glyphosate-imazapyr herbicide) and wildfires across gradients in soil properties. Based on change in P. australis cover during six measurement events over 24 months, 24 study sites formed three groups: 1) decreasing cover, where initially high P. australis cover (60-85%) decreased to < 5% following multiple cutting or herbicide treatments; 2) sustaining low cover, where wildfire or clearing was associated with initially low P. australis cover which remained low (< 30%) after multiple herbicide applications; and 3) sustaining high cover (45-100% initially and remaining 30-100%), including sites unmanaged or treated/burned only once. High soil salinity correlated with low post-management P. australis cover. No native plants were detected in the sustaining high P. australis cover group, despite natives occurring in the seed bank. Where management reduced P. australis cover, minimal native plant colonization did occur. Secondary invasion by other non-native plants was nearly absent. Our results suggest that if P. australis can be initially cleared, multiple herbicide applications can persistently keep cover low, especially on drier, saline soils. Slow native plant colonization suggests that a phased approach may be useful to initially reduce P. australis cover, keep it low via repeated treatments, and actively revegetate sites with native species tailored to the moisture-salinity gradient across P. australis-invaded habitats.

Assessment of Metal Pollution in Sediments and Their Bioaccumulation in Phragmites australis from Shoor River, Iran

ABSTRACT Heavy metal contamination is a serious global issue that threatens both environmental and human health. This study investigated the levels of 12 heavy metals in sediments, roots, stems, and leaves of Phragmites australis (common reed) from a river in Iran, using an inductively coupled plasma optical emission spectrometer (ICP-OES). The sediment metal concentration order was: Aluminum (Al) > Iron (Fe) > Manganese (Mn) > Zinc (Zn) > Magnesium (Mg) > Nickel (Ni) > Chromium (Cr) > Lead (Pb) > Copper (Cu) > Arsenic (As) > Vanadium (V) with Cadmium (Cd) below detection limit. Concentrations of As, Ni, Pb, and Zn in the sediments exceeded background values. According to sediment quality guidelines (SQGs), metal concentrations were between the threshold effect level (TEL) and the probable effect level (PEL), remaining below the severe effect level (SEL), except for Ni. Average metal concentrations in plant tissues were lower than in sediment samples, with roots showing higher levels of Cd, V, Cu, Pb, Zn, As, Al, Mg, and Fe than in the shoots, while leaves had higher Ni, Cr, and Mn. The bioaccumulation factor of less than 1 (except for V) indicates limited bioavailibility of these metals.

Assessment of Water Status, Bottom Sediments, Macrophytes in the Light of Index Analysis and Geochemical Parameters of Selected Dam Reservoirs of Kielce Upland (Poland)

Concentrations of trace elements such as Cr, Zn, Cd, Co, Mn, Cu, Ni, Pb, and Fe were investigated in water, bottom sediments, and macrophytes (Phragmites australis and Typha latifolia L.) collected from the Borków, Wilków, and Rejów water reservoirs in the Kielce Upland (Poland). The main objective of this study was to investigate the condition of water, bottom sediments, and macrophytes in selected three sedimentary basins of the Kielce Upland and to identify natural and anthropogenic factors influencing this condition. The secondary objectives were (i) to determine the contents of trace metals in water, bottom sediments, and macrophytes, (ii) to assess the quality of abiotic and biotic elements of the ecosystem based on selected criteria, (iii) to compare reservoirs in terms of pollution, and (iv) to determine the ability of macrophytes to be used as a bioindicator of water/sediment pollution. Field tests were conducted in 2021. The trace metals in water were determined by ETAAS (Cr, Cd, Mn, Cu, Ni, Pb) and FAAS (Zn), and spectrophotometry method (Fe). The trace metals in sediments and macrophytes, including Cr, Zn, Cd, Co, Mn, Cu, Ni, Pb, and Fe, were detected using ICP-OES method. Contamination of bottom sediments with potentially toxic metals was determined based on the geo-accumulation index (Igeo), contamination factor (CF), and pollutant load index (PLI). Statistical analyses were performed using the Statistica PL 13.1. The analyses showed that the accumulation of trace elements in the surface layer of the reservoir sediments increases as follows: in Borków, Cd < Co < Ni < Cu < Pb < Cr < Zn < Mn < Fe; in Wilków, Cd < Co < Cu < Ni < Pb < Cr < Zn < Mn < Fe; and in Rejow, Cd < Co = Cu = Ni = Pb < Zn < Cr < Mn < Fe. It was shown that the average distribution of metals in the bottom sediments of the studied reservoirs was as follows: Borków > Wilków > Rejów. Research has shown that the degree of trace metal accumulation increases as follows: water < sediments < macrophytes (except Pb from the reservoir in Borków).

Sensitizations to pollen differ between Central European and Sub-Saharan African atopic dermatitis patients

Summary Background Atopic dermatitis (AD) is often associated with allergic comorbidities, such as allergic asthma or allergic rhinoconjunctivitis (ARC). Sensitizations to pollen can directly impact AD, as patients can experience exacerbation during pollen season. This study aims to gain more insights into the pollen sensitization patterns of AD patients in Central Europe compared with sub-Saharan Africa (SSA). Methods We performed a case–control study involving a total of 90 participants: 20 AD patients and 10 healthy controls (HC) each from Switzerland (CH), Tanzania (TZ), and Madagascar (MD). We collected clinical data and serum samples and performed a multiplex IgE test (ALEX2 Allergy Explorer, MacroArray Diagnostics, Vienna, Austria). Results The prevalence of ARC and asthma in AD patients was similar in all countries (ARC: 60% TZ, 70% CH, 75% MD; asthma: 25% TZ, 30% CH, 20% MD). Total IgE levels were significantly higher in both SSA HC populations compared with the Swiss HC. The analysis of specific IgE levels revealed major differences in sensitization patterns between Africa and Europe, especially regarding grass pollen allergens. Swiss AD patients were sensitized to various grass pollen such as Bahia grass, Bermuda grass, common reed, perennial ryegrass, rye, and timothy grass. However, these allergens were irrelevant in the SSA population: no AD patient or HC subject was sensitized to the tested grass pollen. Conclusion The considerably different sensitization patterns between European and SSA AD patients warrant the development of allergy testing and desensitization therapies tailored to the African setting. Therefore, there is a need to characterize local pollen types and counts.

Plant-Based Flocculants as Sustainable Conditioners for Enhanced Sewage Sludge Dewatering

With the aim to establish clean and sustainable sludge treatment, green conditioning using natural flocculants has recently gained a growing interest. In this study, a variety of plant materials, namely Moringa (Moringa oleifera) seeds, Fenugreek (Trigonella foenum-graecum) seeds, Potato (Solanum tuberosum) peels, Aloe (Aloe vera) leaves, Cactus (Opuntia ficus indica) cladodes, and Phragmites (Phragmites australis) stems, were evaluated for their potential bioflocculant activity in conditioning sewage sludge. They were thoroughly characterized to determine their active flocculating compounds. Sludge dewaterability was evaluated by assessing various sludge parameters, including specific resistance to filtration (SRF), dryness of filtration cake (DC), and total suspended solid removal (TSS) from sludge filtrate. The collected results from various physicochemical characterizations of plant materials suggest that the main flocculating agents are carbohydrates in Cactus and Fenugreek and proteins in Moringa, Potato, and Phragmites. Additionally, all tested plant-based flocculants demonstrated effective dewatering performance. Interestingly, compared to the chemical flocculant polyaluminum chloride, Moringa and Cactus showed superior conditioning effects, yielding the lowest SRF values and the highest DC. As a result, the use of these natural flocculants improved sewage sludge filterability, leading to a significant removal of total suspended solids from the filtrate. The conditioning properties of Moringa and Cactus can be attributed to their high protein and sugar content, which facilitates the effective separation of bound water from solids through charge neutralization and bridging mechanisms. Thus, green conditioning using plant-based flocculants, particularly Moringa and Cactus materials, presents a promising and eco-friendly approach to enhance sewage sludge dewatering for safer disposal and valorization.

Stronger increase of methane emissions from coastal wetlands by non‐native Spartina alterniflora than non‐native Phragmites australis

Societal Impact StatementThe invasive species S. alterniflora and P. australis are fast growing coastal wetland plants sequestering large amounts of carbon in the soil and protect coastlines against erosion and storm surges. In this global analysis, we found that Spartina and Phragmites increase methane but not nitrous oxide emissions, with Phragmites having a lesser effect. The impact of the invasive species on emissions differed greatly among different types of native plant groups, providing valuable information to managers and policymakers during coastal wetland planning and restoration efforts. Further, our estimated net emissions per wetland plant group facilitate regional and national blue carbon estimates.Summary Globally, Spartina alterniflora and Phragmites australis are among the most pervasive invasive plants in coastal wetland ecosystems. Both species sequester large amounts of atmospheric carbon dioxide (CO2) and biogenic carbon in soils but also support production and emission of methane (CH4). In this study, we investigated the magnitude of their net greenhouse gas (GHG) release from invaded and non‐invaded habitats. We conducted a meta‐analysis of GHG fluxes associated with these two species and related soil carbon content and plant biomass in invaded coastal wetlands. Our results show that both invasive species increase CH4 fluxes compared to uninvaded coastal wetlands, but they do not significantly affect CO2 and N2O fluxes. The magnitude of emissions from Spartina and Phragmites differs among native habitats. GHG fluxes, soil carbon and plant biomass of Spartina‐invaded habitats were highest compared to uninvaded mudflats and succulent forb‐dominated wetlands, while being lower compared to uninvaded mangroves (except for CH4). This meta‐analysis highlights the important role of individual plant traits as drivers of change by invasive species on plant‐mediated carbon cycles.

How to alleviate seasonal limitations on water quality in farmland ditches? The importance of plant selection and configuration

In subtropical monsoon climate regions, traditional plants in constructed wetlands such as farmland ditches underperform in cold months, detracting from both purification capacity and esthetic appeal. To alleviate this weakness, this study introduced Phalaris arundinacea, a species with strong adaptability and cold tolerance, into a plant community dominated by Phragmites australis, constructing an ingenious composite plant community for year‐round water quality restoration and enhancement of attractiveness. First, laboratory simulations revealed significant seasonal differences in the removal rates of ammonia nitrogen (NH3‐N), total nitrogen (TN), and total phosphorus (TP) by the P. arundinacea community and P. australis community under different pollutant loads. Phragmites australis showed superior NH3‐N and TN removal capabilities from May to October, whereas P. arundinacea excelled in the rest of the months throughout the year. For TP removal, P. australis outperformed P. arundinacea from July to October, while P. arundinacea was more effective from January to May. We then verified this in rear farmland ditches, where P. australis were strategically partial substituted with P. arundinacea (Partial Replacement Treatment [PRT]), and compared it with unchanged farmland ditches (Control Treatment). We found that PRT enhanced decontamination efficiency over the year, especially significantly improving the water quality during colder months. Hence, this study advocates a novel strategy for effective annual decontamination and maintenance of wetlands such as farmland ditches, highlighting the importance of seasonally adaptive plant communities for water restoration. This transformative approach dramatically advances the field of wetland management, insisting on the important role of cold‐resistant species for year‐round ecosystem service optimization.

The genome sequence of common reed, Phragmites australis (Cav.) Steud. (Poaceae)

We present a genome assembly from an individual Phragmites australis (the common reed; Streptophyta; Magnoliopsida; Poales; Poaceae). The genome sequence has a total length of 848.70 megabases. Most of the assembly is scaffolded into 24 chromosomal pseudomolecules, supporting the specimen being an allotetraploid (2n = 4x = 48). The three mitochondrial assemblies had lengths of 304.58, 92.24, and 76.54 kilobases and the plastid genome assembly had a length of 137.67 kilobases. Gene annotation of this assembly on Ensembl identified 47,513 protein-coding genes.

Metatranscriptomic analysis to reveal the coupling between nitrogen fixation and CH4 oxidation in root tissues of Phragmites australis

Metatranscriptomic analysis to reveal the coupling between nitrogen fixation and CH4 oxidation in root tissues of Phragmites australis

Understanding the interaction between soil ORP and enzyme activity: How does wetland type affect constructed wetland performance for the advanced treatment of swine wastewater?

Constructed wetlands (CWs) are widely used for the advanced treatment of swine wastewater. Wetland type is the most critical parameter for engineering applications; therefore, the performance of horizontal/vertical subsurface flow CWs (HSFCWs and VSFCWs) was explored over one year of operation. The effects of five antibiotics (40 μg/L each), copper (Cu, 1.0 mg/L), and their combination on CW performance and soil oxidation–reduction potential (ORP) and enzyme activity were investigated. The annual removal efficiencies of HSFCWs and VSFCWs for total organic carbon (TOC), nitrogen, and phosphorus were 72.03 %–84.49 % and 87.15 %–90.72 %, for antibiotics were 91.35 %–99.52 % and 87.33 %–99.57 %, and for Cu were 97.37 %–97.44 % and 95.52 %–96.85 %, respectively. The CWs removed antibiotics through substrate adsorption, plant absorption, and biodegradation. Total antibiotic residues in HSFCW and VSFCW soils ranged from 6.29 to 17.31 and 24.57 to 589.07 μg/kg, respectively, and enrofloxacin and roxithromycin posed medium and high risks in VSFCW non-rhizosphere soil. The amount of residual antibiotics in Phragmites australis parts was in the order of fibrous roots > rhizomes > aboveground. ORP and enzyme activities were greater in rhizosphere soil than in non-rhizosphere soil and greater in the VSFCWs than in the HSFCWs. CW performance and soil enzyme activities decreased under the stress of antibiotics and coexistence of antibiotics and Cu. These findings advance our knowledge of CW design, elucidate the unique advantages of CWs, and offer efficient operation strategies for swine wastewater advanced treatment, helping researchers recognize the adverse effects of antibiotics on CWs.

Characteristics of Phytoplankton Community Structure in Lakes of Wetlands Dominated by Different Aquatic Plants and Its Driving Factors

In wetland ecosystems, small shallow lakes are critical transition zones of land and water, which are usually dominated by aquatic plants with different growth forms. However, the differences and key influencing factors of phytoplankton communities in shallow lakes dominated by different aquatic plants are unclear. On this basis, nine surveys were conducted at five sampling sites of three lakes in Zhangye National Wetland Park from June to November in 2022, which were respectively dominated by the emergent Phragmites australis （LL）, the submerged Potamogeton perfoliatus （CL）, and the floating-leaved Nymphaea tetragona （SL）. During the study period, the three lakes showed obvious habitat differences. A total of 237 species of phytoplankton in seven phyla and 93 genera were identified in the three lakes, including 189 species, 151 species, and 147 species in the LL, CL, and SL lakes, respectively. Among them, Ulnaria acus, Scenedesmus quadricauda, Achnanthidium minutissimum, Nitzschia stagnorum, Navicula radiosa, and Gymnodinium aeruginosum were shared dominant species of all three lakes, indicating that they had strong environmental adaptability, whereas Navicula lanceolala, Encyonopsis cesatii, and Eunotia diodon and Cymbella aequalis were only dominant in the CL, LL, and SL lakes, respectively. Simultaneously, these dominant algae appeared with obviously distinct statuses of niche width, niche overlap, and interspecific correlation among the three lakes. Using principal coordinate analysis （PCoA） and permutational multivariate analysis of variance （PERMANOVA）, significant differences were found in algal community composition among the three lakes （P<0.001）. Multiple regression on （dis）similarity matrices analysis （MRM） showed that the heterogeneity of phytoplankton communities among the three lakes was positively affected by NO3--N and pH and negatively affected by dissolved oxygen （DO） and was closely positively correlated with the abundance of six dominant species, namely, S. quadricauda, U. acus, N. stagnorum, Pseudoanabaena sp., Merismopedia punctata, and A. minutissimum. These results indicate that aquatic plants with different growth types could affect the composition, structure, and stability of phytoplankton communities in the same habitat with them by shaping their habitat heterogeneity. Therefore, selecting specific growth types of aquatic plants for aquatic ecosystem restoration in wetland construction and management will be conducive to regulate the state of water habitat and phytoplankton community structure effectively.

Biodiversity and Soil Reinforcement Effect of Vegetation Buffer Zones: A Case Study of the Tongnan Section of the Fujiang River Basin

The riparian vegetation buffer zone is an important component of riverbank ecosystems, playing a crucial role in soil consolidation and slope protection. In this study, the riparian vegetation buffer zones in the Tongnan section of the Fujiang River Basin were selected as the research object. Surveys and experiments were conducted to assess the species composition and the soil and water conservation effectiveness of the riparian vegetation buffer zone. There are a total of 35 species, mainly comprising angiosperms and ferns. The dominant species include Cynodon dactylon, Setaria viridis, Phragmites australis, Erigeron canadensis, and Melilotus officinalis. The Patrick richness index (R) and Shannon–Wiener diversity index (H) are more significantly influenced by the types of land use in the surrounding area, whereas the impact on the Simpson diversity index (D) and Pielou uniformity index (E) is comparatively less pronounced. When the root diameter is less than 0.2 mm, the tensile strength of Cynodon dactylon roots is the highest. For root diameters larger than 0.2 mm, Melilotus officinalis roots exhibit the highest tensile strength. The presence of plant root systems significantly reduces erosion, delaying the time to reach maximum erosion depth by 1–4 min, decreasing erosion depth by 9–38 mm, and reducing the total amount of erosion by 20.17–58.90%. The anti-scouribility effect of Cynodon dactylon is significantly better than that of Setaria viridis. The root system notably enhances soil shear strength, delaying the shear peak by 0.26–4.8 cm, increasing the shear peak by 4.76–11.37 kPa, and raising energy consumption by 23.76–46.11%. Phragmites australis has the best resistance to shear, followed by Erigeron canadensis, with Melilotus officinalis being the least resistant. Therefore, to balance the anti-scouribility effect and shear resistance of plant roots, it is recommended to use a combination of Cynodon dactylon and Phragmites australis for shallow-rooted and deep-rooted planting. This approach enhances the water and soil conservation capacity of riverbanks.

The Relationship between the Density of Winter Canola Stand and Weed Vegetation

Canola (Brassica napus L.) is an important oilseed crop that provides essential vegetable oil but faces significant competition from weeds that are influenced by various agronomic practices and environmental conditions. This study examines the complex interactions between canola stand density and weed intensity over three growing seasons, identifying a total of 27 weed species. It is important to establish a connection between the density of winter canola stands, the intensity of weeding and the response of individual weed species in real conditions. The case study was executed on plots located in the Přerov district (Olomouc region, Czech Republic). The assessment was carried out during two periods—autumn in October and spring in April. Canola plants (plant density) were counted in each evaluated area, weed species were identified, and the number of plants for each weed species was determined. Half of the plots were covered with foil before herbicide application to prevent these areas from being treated with herbicides. We used redundancy analysis (RDA) to evaluate the relationships between canola density and weed dynamics, both with and without herbicide treatment. The results show the ability of canola to compete with weeds; however, that is factored by the density of the canola stand. In dense stands (over 60 plants/m²), canola is able to suppress Galium aparine L., Geranium pusillum L., Lamium purpureum L., Papaver rhoeas L. and Chamomilla suaveolens (Pursh) Rydb. Nevertheless, there are weed species that grow well even in dense canola stands (Echinochloa crus-galli (L.) P. Beauv., Phragmites australis (Cav.) Steud., Tripleurospermum inodorum (L.) Sch. Bip. and Triticum aestivum L.). These findings highlight the potential for using canola stand density as a strategic component of integrated weed management to reduce herbicide reliance and address the growing challenge of herbicide-resistant weed populations. This research contributes significantly to our understanding of the dynamics of weed competition in canola systems and informs sustainable agricultural practices for improved crop yield and environmental stewardship.

Optimization of reed-based polyol production driven by response surface methodology and machine learning: Process modeling and hydroxyl value prediction

In pursuit of sustainable development goals, the transformation of biomass resources into high-value chemicals has become a focal point within the academic community. Despite being a biomass resource, reed (Phragmites australis) has not yet fully realized its potential in the production of bio-based polyols. This study utilized Response Surface Methodology (RSM) and an Artificial Neural Network (ANN) enhanced by a Genetic Algorithm (GA) to model and optimize the liquefaction process of reeds. Furthermore, this study employed a pre-existing predictive model to estimate the hydroxyl value of reed-derived liquefaction products, thereby aiming to curtail expenses during the biomass chemical development phase. The results demonstrated that both the RSM and GA-ANN models accurately predict bio-polyol yield, with the RSM model outperforming the ANN model. Based on optimal conditions predicted by the RSM model, the best experimental process parameters were established: raw material particle size 2–12 mesh, solid-liquid ratio 5:1, glycerol content 32.5 %, catalyst content 3.6 %, temperature 169 °C, and reaction time 58 minutes. Under these conditions, the polyol yield reached 89.145 %, with a relative deviation of 2.366 %, and the bio-polyol exhibited a viscosity of 0.51 Pa·s. The predicted hydroxyl value for the bio-based polyol was found to be 399.19 mg KOH/g. The liquefied product is rich in hydroxyl groups, indicating its potential application value in preparing bio-based polymer materials. This study introduces innovative approaches to the economical production of bio-based polyols at the laboratory scale, which may pave the way for their broader industrial implementation.

Genome-wide analysis tracks the emergence of intraspecific polyploids in Phragmites australis

Polyploidization plays an important role in plant speciation and adaptation. To address the role of polyploidization in grass diversification, we studied Phragmites australis, an invasive species with intraspecific variation in chromosome numbers ranging from 2n = 36 to 144. We utilized a combined analysis of ploidy estimation, phylogeny, population genetics and model simulations to investigate the evolution of P. australis. Using restriction site-associated DNA sequencing (RAD-seq), we conducted a genome-wide analysis of 88 individuals sourced from diverse populations worldwide, revealing the presence of six distinct intraspecific lineages with extensive genetic admixture. Each lineage was characterized by a specific ploidy level, predominantly tetraploid or octoploid, indicative of multiple independent polyploidization events. The population size of each lineage has declined moderately in history while remaining large, except for the North American native and the US Land types, which experienced constant population size contraction throughout their history. Our investigation did not identify direct association between polyploidization events and grass invasions. Nonetheless, we observed octoploid and hexaploid lineages at contact zones in Romania, Hungary, and South Africa, suggestively due to genomic conflicts arising from allotetraploid parental lineages.

Riparian vegetation entraps macroplastics along the entire river course: implications for eco-safety activities and mitigation strategies

Macroplastic litter causes detrimental effects on freshwater biota affecting human health. Despite the significant role of rivers in transporting plastic waste, most plastics remain in fluvial ecosystems, accumulating in infrastructure, river sediment, and (riverbank) vegetated areas. However, the entrapment of plastics by riparian vegetation was overlooked, particularly in upper and middle river courses. For the first time, we aimed to quantify the entrapment of plastics by riparian vegetation along the entire river course. Sampling riparian areas in the upper, middle, and lower river courses in central Italy, we found 1,548 macrolitter items, with vegetation entrapping 93.9% of total litter. Riverbank and riparian plastics acted as long-term indicators of river plastics. We emphasized the trapping efficiency at the species level highlighting that the best plastic trapper species were trees, shrubs and reeds (Populus spp., Salix spp., Rubus ulmifolius, Phragmites australis, and Ficus carica), blocking 85.4% of the total macrolitter entrapped by plants. Plastic pieces, bags, bandages, sanitary items, and packaging were among the most trapped types. Furthermore, vegetation in the lower river course exhibited greater plastic entrapment compared to the upper and middle courses, following the fact that all the river courses contribute to plastic pollution. Recognizing the potential of riparian vegetation as a valuable ecosystem service in trapping macroplastics, further research should explore the characteristics and structures of riparian communities involved in this process. By developing eco-safe practices and mitigation strategies based on these findings, we might contribute significantly to managing, conserving, and restoring riverine ecosystems.