Phragmites Australis Research Articles

Telomere-to-telomere Phragmites australis reference genome assembly with a B chromosome provides insights into its evolution and polysaccharide biosynthesis

Phragmites australis is a globally distributed grass species (Poaceae) recognized for its vast biomass and exceptional environmental adaptability, making it an ideal model for studying wetland ecosystems and plant stress resilience. However, genomic resources for this species have been limited. In this study, we assembled a chromosome-level reference genome of P. australis containing one B chromosome. An explosion of LTR-RTs, centered on the Copia family, occurred during the late Pleistocene, driving the expansion of P. australis genome size and subgenomic differentiation. Comparative genomic analysis showed that P. australis underwent two whole gene duplication events, was segregated from Cleistogenes songorica at 34.6 Mya, and that 41.26% of the gene families underwent expansion. Based on multi-tissue transcriptomic data, we identified structural genes in the biosynthetic pathway of pharmacologically active Phragmitis rhizoma polysaccharides with essential roles in rhizome development. This study deepens our understanding of Arundinoideae evolution, genome dynamics, and the genetic basis of key traits, providing essential data and a genetic foundation for wetland restoration, bioenergy development, and plant stress.

Classification and Monitoring of Salt Marsh Vegetation in the Yellow River Delta Based on Multi-Source Remote Sensing Data Fusion.

Salt marsh vegetation in the Yellow River Delta, including Phragmites australis (P. australis), Suaeda salsa (S. salsa), and Tamarix chinensis (T. chinensis), is essential for the stability of wetland ecosystems. In recent years, salt marsh vegetation has experienced severe degradation, which is primarily due to invasive species and human activities. Therefore, the accurate monitoring of the spatial distribution of these vegetation types is critical for the ecological protection and restoration of the Yellow River Delta. This study proposes a multi-source remote sensing data fusion method based on Sentinel-1 and Sentinel-2 imagery, integrating the temporal characteristics of optical and SAR (synthetic aperture radar) data for the classification mapping of salt marsh vegetation in the Yellow River Delta. Phenological and polarization features were extracted to capture vegetation characteristics. A random forest algorithm was then applied to evaluate the impact of different feature combinations on classification accuracy. Combining optical and SAR time-series data significantly enhanced classification accuracy, particularly in differentiating P. australis, S. salsa, and T. chinensis. The integration of phenological features, polarization ratio, and polarization difference achieved a classification accuracy of 93.51% with a Kappa coefficient of 0.917, outperforming the use of individual data sources.

Mitochondrial Genome Insights into Evolution and Gene Regulation in Phragmites australis.

As a globally distributed perennial Gramineae, Phragmites australis can adapt to harsh ecological environments and has significant economic and environmental values. Here, we performed a complete assembly and annotation of the mitogenome of P. australis using genomic data from the PacBio and BGI platforms. The P. australis mitogenome is a multibranched structure of 501,134 bp, divided into two circular chromosomes of 325,493 bp and 175,641 bp, respectively. A sequence-simplified succinate dehydrogenase 4 gene was identified in this mitogenome, which is often translocated to the nuclear genome in the mitogenomes of gramineous species. We also identified tissue-specific mitochondrial differentially expressed genes using RNAseq data, providing new insights into understanding energy allocation and gene regulatory strategies in the long-term adaptive evolution of P. australis mitochondria. In addition, we studied the mitogenome features of P. australis in more detail, including repetitive sequences, gene Ka/Ks analyses, codon preferences, intracellular gene transfer, RNA editing, and multispecies phylogenetic analyses. Our results provide an essential molecular resource for understanding the genetic characterisation of the mitogenome of P. australis and provide a research basis for population genetics and species evolution in Arundiaceae.

Efficiency of Phragmites australis (Cav.) Trin. Ex Steud. and Typha latifolia L. in remediating methyldiethanolamine (MDEA) from Ilam gas refinery wastewater: Isotherm and kinetic studies.

This study presents a novel, eco-friendly method for removing methyldiethanolamine (MDEA) from wastewater, addressing its environmental impact and elevated chemical oxygen demand (COD) from gas refineries. We employed two wetland plants, Phragmites australis and Typha latifolia, utilizing a hydroponics approach to assess MDEA removal efficiency. Wastewater samples from the Ilam gas refinery in Iran were tested at varying initial concentrations (50 to 1600ppm) over three consecutive 7-day periods, with a 1-day rest interval. Key factors influencing MDEA absorption-contact time, initial effluent concentration, and pH-were systematically analyzed. Results indicated a significant decrease in pH, COD, and MDEA concentration during the first four days. Kinetic modeling employed pseudo-first-order (PFO) and pseudo-second-order (PSO) models, alongside adsorption isotherms (Langmuir, Freundlich, Temkin, Dobinin-Radeshkovich, and Louis), to evaluate MDEA absorption capacity. The Langmuir isotherm best described the absorption characteristics of both plants. Maximum adsorption capacities were recorded for P. australis at 1.181, 2.018, and 3.77mg/L across the experimental periods, while T. latifolia showed values of 0.779, 1.099, and 2.99mg/L. Kinetic analysis favored the pseudo-second-order model for both species. Our findings suggest that P. australis is the more effective candidate for phytoremediation of MDEA in wastewater treatment applications.

Photosynthetic traits of Phragmites australis along an ecological gradient and developmental stages

Photosynthetic traits of Phragmites australis along an ecological gradient and developmental stages

Interaction Between Root Exudates and PFOS Mobility: Effects on Rhizosphere Microbial Health in Wetland Ecosystems

Perfluorooctanesulfonate (PFOS), a persistent organic pollutant, poses significant ecological risks. This study investigates the effects of PFOS on rhizosphere microbial communities of two wetland plants, Lythrum salicaria (LS) and Phragmites communis (PC). We conducted microcosm experiments to analyze the physiological status of soil microbes under varying PFOS concentrations and examined the role of root exudates in modulating PFOS mobility. Flow cytometry and soil respiration measurements revealed that PFOS exposure increased microbial mortality, with differential impacts observed between LS and PC rhizospheres. LS root exudates intensified microbial stress, whereas PC exudates mitigated PFOS toxicity. Thin-layer chromatography indicated that LS exudates decreased PFOS mobility, leading to higher local concentrations and increased microbial toxicity, while PC exudates enhanced PFOS mobility, reducing its local impact. Fourier-transform infrared spectroscopy and excitation-emission matrix fluorescence spectroscopy of root exudates identified compositional shifts under PFOS stress, highlighting distinct defense strategies in LS and PC. These findings underscore the importance of plant-microbe interactions and root exudate composition in determining microbial resilience to PFOS contamination.

Development of reed-based cellulose aerogel: a sustainable solution for crude oil spill clean-up.

This study focused on fabricating a cellulose aerogel for oil spill clean-up, using common reed (Phragmites australis) as the cellulose source. The process involved isolating cellulose from reed via traditional Kraft pulping, considering the effects of key factors on the isolated cellulose content. After a two-stage HP bleaching sequence, the highest cellulose content achieved was 27.2%, with 80% ISO brightness and 1% ash content under mild Kraft pulping conditions of 30% sulfidity, 20% active alkali (AA), sustained cooking at 165°C for 3 h, and a liquor-to-reed ratio of 8 : 1. Subsequently, reed-based cellulose aerogel was fabricated via a freeze-drying method using an eco-friendly NaOH/poly(ethylene glycol) aqueous solvent system, which was then modified with methyltrimethoxysilane. The resulting aerogel exhibited remarkable characteristics, including a low density of 0.04 g cm-3, high porosity of 96%, high hydrophobicity with a water contact angle (WAC) of 141°, and a superior crude oil adsorption capacity of 35 g g-1. Comprehensive characterizations of the fabricated materials, including scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis/differential scanning calorimetry, and WAC measurements, were evaluated. This interdisciplinary study explores the commercial promise of reed-based cellulose aerogel as a sustainable solution for oil spill clean-up efforts.

Rhizosphere microbial community structure and PICRUSt2 predicted metagenomes function in heavy metal contaminated sites: A case study of the Blesbokspruit wetland.

This study investigated the microbial diversity inhabiting the roots (rhizosphere) of macrophytes thriving along the Blesbokspruit wetland, South Africa's least conserved Ramsar site. The wetland suffers from decades of pollution from mining wastewater, agriculture, and sewage. The current study focused on three macrophytes: Phragmites australis (common reed), Typha capensis (bulrush), and Eichhornia crassipes (water hyacinth). The results revealed a greater abundance and diversity of microbes (Bacteria and Fungi) associated with the free-floating E. crassipes compared to P. australis and T. capensis. Furthermore, the correlation between microbial abundance and metals, showed a strong correlation between fungal communities and metals such as nickel (Ni) and arsenic (As), while bacterial communities correlated more with lead (Pb) and chromium (Cr). The functional analysis predicted by PICRUSt2 identified genes related to xenobiotic degradation, suggesting the potential of these microbes to break down pollutants. Moreover, specific bacterial groups - Proteobacteria, Verrucomicrobia, Cyanobacteria, and Bacteroidetes - were linked to this degradation pathway. These findings suggest a promising avenue for microbe-assisted phytoremediation, a technique that utilizes plants and their associated microbes to decontaminate polluted environments.

Photic versus aphotic production of organohalogens from native versus invasive wetland plants-derived dissolved organic matter.

The aphotic formation of natural organohalogens (NOHs) remains inadequately understood, in contrast to the well-documented photo-halogenation process of dissolved organic matter (DOM), despite the significant biogeochemical implications associated with NOHs. This study investigates the differences in the formation of chlorinated and brominated compounds from the photochemical and aphotic reactions of native Phragmites australis (PA-DOM) and invasive Spartina alterniflora (SA-DOM). The findings indicate that SA-DOM exhibits a greater potential for photochemical halogenation, attributed to its higher aromatic content and enhanced photostability. Utilizing advanced mass spectrometry, the study identifies nitrogen-containing and free saturated compounds as primary precursors for both types of DOM during photochemical halogenation. Notably, significant disparities in the halogenation processes of lignin/CRAM, nitrogen-containing/free saturated compounds, and amino sugars between SA-DOM and PA-DOM are observed, leading to a higher production of NOHs in PA-DOM during aphotic reactions compared to photic reactions, even in artificial seawater. Furthermore, the study emphasizes the critical role of dissolved oxygen in the formation of NOHs from PA-DOM under aphotic conditions. Given the rapid fluctuations in oxygen levels, salinity, and solar intensity, alongside tidal and diurnal cycles, the significance of both photic and aphotic pathways for NOHs formation should not be overlooked.

Determination and Removal of Potentially Toxic Elements by Phragmites australis (Cav.) Trin. ex Steud. (Poaceae) in the Valles River, San Luis Potosí (Central Mexico)

The contamination of rivers by potentially toxic elements (PTEs) is a problem of global importance. The Valles River is Ciudad Valles’ (Central Mexico) main source of drinking water. During the four seasons of the year, water samples (n = 6), sediment samples (n = 6), and Phragmites australis plants (n = 10) were taken from three study sites selected based on the presence of anthropogenic activities in the Valles River. A graphite atomic absorption spectrophotometer estimated elements in the water, and an energy-dispersive X-ray fluorescence spectrometer quantified elements in sediments and plant samples. Phragmites australis accumulated metal(loid)s mainly in the roots during all seasons of the year. Water samples from all sites recorded PTEs (As, Pb, Cd, and Hg), with primary sources identified as the sugar industry, urban and industrial wastewater, and the combustion of fossil fuels. Sediment samples showed concentrations of Hg, Mn, Ni, Zn, Pb, V, Cu, Cr, and Cd, attributed to agricultural practices, industrial activity, and urbanization. P. australis is an alternative for in situ phytoremediation because this macrophyte can bioaccumulate different elements in its roots, such as Mn, Rb, V, Sr, Cu, Zn, Pb, Ni, and As.

Efficient phytoremediation of first-flush storm water using an innovative constructed wetland: a pilot-scale study towards sustainable water reuse

Phytoremediation for wastewater treatment is a sustainable and cost-effective alternative to traditional methods. This study focuses on treating First-Flush StormWaters (FFSWs), which carry contaminants from urban surfaces, causing water or soil pollution. The performance of an innovative Nature-Based Solution (NBS), using a Hybrid-flow Constructed Wetland (HCW), was tested at a pilot scale to meet quality standards for reusable wastewater. The aquatic macrophytes employed in the HCW Arundo donax, Phragmites australis and Juncus acutus were previously selected by means of a pot phytotoxicity experiment using a synthetic FFSW prepared ad hoc. The HCW remediation efficacy was evaluated both on the synthetic FFSW and real one collected from an industrial hardstanding. A significant pollutant removal (50–100%), for both FFSWs, was obtained after just 72–96 h of their recirculation in the HCW; in addition, a significative reduction of the total bacterial count was observed after their treatment in the HCW. The innovative multi-layered filter beds of the HCW effectively remediated FFSW to meet reuse standards. Additionally, the HCW significantly reduced the required surface area for optimal water remediation by five times per Inhabitant Equivalent, addressing a key limitation for widespread use of such Nature-Based Solutions in wastewater treatment.

Plant community, geomorphology, and macrobenthos as drivers of spatial variations in soil carbon and nitrogen in a coastal shoal

AbstractCoastal salt marsh wetlands are crucial reservoirs of soil carbon (C) and nitrogen (N). However, the effects of plant type, geomorphology, and macrobenthos on spatial variations in soil C and N in coastal wetlands remain unclear. In this study, the spatial distribution of soil C and N components was investigated in a coastal wetland (Jiuduansha Shoal) in the Yangtze Estuary, and plant type distribution, plant biomass, soil properties, and macrobenthos species and biomass along the geomorphological gradient were measured. The results showed that the amounts and stocks of soil total C, soil organic C, soil total N, and soil microbial biomass C and N at the Spartina alterniflora (SA) and Phragmites australis (PA) sites were significantly higher than those at the bare mudflat (BM) sites. The soil and microorganism C and N variables showed a remarkable increasing trend from low- to high-elevation sites. The abundance of macrobenthos at the Scirpus mariqueter site was the highest among the plant communities and was significantly higher than that at the Zizania latifolia (ZL) and BM sites. The air-free dry weight (AFDW) of macrobenthos in the PA community was the highest among the communities. The variability in soil C and N was mainly sensitive to plant biomass, soil water content, bulk density, macrobenthos AFDW, particle size, electrical conductivity, and nutrient levels. We suggest that the synergetic effects of biotic and abiotic factors in the intertidal environment need to be fully considered in assessing and managing the C and N pools of coastal salt marshes in East China.

Determination of Nutritional Values of Cattail (Typha latifolia L.) and Common Reed (Phragmites australis Cav.) Silages

Cattail (Typha latifolia L.) and common reed (Phragmites australis Cav.) are species that grow spontaneously in wetlands and produce high production. This research was carried out to reveal the potential of these species to be used as an alternative silage plant. The plants were harvested in two different development periods (boot stage and flowering stage) in 2021 and 2022, and they were siled by mixing barley crushed at four different rates (0, 5, 10 and 15%). In the research, dry matter (DM), crude protein (CP), ADF, NDF and pH of the silages were determined. The results obtained showed different results of silage quality parameters depending on the species, cutting time and contribution rate. It has been determined that the forms made in the early period are better in terms of crude protein content. It has been found that the additive improves silage quality, so adding 10-15% cracked barley is beneficial. However, it has been determined that very good fermentation does not occur with current practices.

Great Lakes coastal wetland plant biodiversity increases following the manual removal of invasive Phragmites australis

Great Lakes coastal wetland plant biodiversity increases following the manual removal of invasive Phragmites australis

Effects of functional type and angular configuration on reflectance anisotropy of aquatic vegetation in ultra-high resolution hyperspectral imagery

ABSTRACT Imaging spectroscopy and lightweight unmanned aerial vehicles (UAVs) have revolutionized remote sensing of vegetation, by providing high spectral and spatial resolution data. Comprehensive wetland monitoring should be based on reliable mapping of biophysical aquatic vegetation parameters, which in turn requires low bias in measured spectra, e.g. minimization of reflectance anisotropy. This study aims to quantitatively investigate how sensor scan direction and solar zenith angle (SZA) affect vegetation spectra over two dominant aquatic plants, Phragmites australis and Nuphar lutea, representing different functional types (i.e. emergent and floating) with divergent canopy structure and affinity with water, using data collected with a hyperspectral (400–1000 nm range) push-broom sensor mounted on a UAV. Anisotropy factor (ANIF), mean reflectance scatterplots and regression analysis were used for assessing the magnitude of spectral anisotropy at both pseudo-leaf and canopy scales. Our findings showed more accentuated anisotropic behaviour in the visible than near-infrared domain at SZA < 60° as the scan direction approaches that of solar principal plane. The increase in reflectance in near-forward direction affects the spectra of floating-leaved N. lutea at both leaf and canopy scales, suggesting the presence of water (as a film over leaves or as canopy background) as a likely anisotropy driver. Backward hotspot is evident in canopy spectra of emergent P. australis, with driving mechanisms similar to terrestrial species (i.e. shadow-hiding). At SZA > 60°, reflectance anisotropy appears to be negligible, independent of functional type and scan direction. This research underscores the importance of considering sun-target-sensor geometry in remote sensing studies on aquatic vegetation.

Influence of Common Reed on Zinc Removal and Soil Bacteria in Constructed Wetlands for Mine Drainage Treating

Influence of Common Reed on Zinc Removal and Soil Bacteria in Constructed Wetlands for Mine Drainage Treating

Photosynthetic and Physiological Characteristics of Three Common Halophytes and Their Relationship with Biomass Under Salt Stress Conditions in Northwest China

Three different types of common halophytes (Haloxylon ammodendron, Tamarix chinensis, and Phragmites australis) in northwest China were used in this study. A field experiment approach was adopted, involving five solutions with different salt concentrations (0, 150, 200, 250, and 300 mmol·L−1) for salt stress treatment. The changes in photosynthetic characteristics and physiological characteristics of three different types of halophytes and their relationship with biomass were measured and analyzed. The results showed that (1) with the increase in salt concentration, the plant height, stem diameter, and biomass of three halophytes showed a downward trend. (2) The chlorophyll a, chlorophyll b, and total chlorophyll contents of Haloxylon ammodendron and Tamarix chinensis first increased and then decreased with the increase in salt concentration. Phragmites australis showed a decreasing trend. The malondialdehyde content of three halophytes showed a clear increasing trend. (3) Under different salt concentrations, the diurnal changes in the net photosynthetic rate, transpiration rate, stomatal conductance, and water use efficiency of three different types of halophytes all showed an “M” trend. The diurnal variation in intercellular carbon dioxide concentration showed a “W” trend. (4) With the increase in salt concentration, the daily average values of the net photosynthetic rate, transpiration rate, and stomatal conductance of three different types of halophytes showed a downward trend. The daily average value of intercellular carbon dioxide concentration showed a “V”-shaped trend of first decreasing and then increasing. The daily average value of water use efficiency showed a “single peak” trend of first increasing and then decreasing. Haloxylon ammodendron and Phragmites australis were mainly limited by stomata at a salt concentration of 0~200 mmol·L−1 and were mainly limited by non-stomata at a salt concentration of 250~300 mmol·L−1. Tamarix chinensis is mainly limited by stomata at a salt concentration of 0~250 mmol·L−1 and is mainly limited by non-stomata at a salt concentration of 300 mmol·L−1. Compared with Haloxylon ammodendron and Phragmites australis, Tamarix chinensis has better water use efficiency, salt tolerance, and adaptability. (5) Meteorological factors, growth morphological factors, physiological factors, photosynthetic factors, and salt concentration have higher explanatory degrees, which have significant effects on the biomass of halophytes. Among them, salt concentration and growth morphological factors have direct core driving effects on the biomass of three different types of halophytes, while meteorological factors, photosynthetic factors, and physiological factors have different effects due to the differences in and complexity of halophytes. This study can provide a theoretical basis for further revealing the adaptation mechanism of different halophytes to salt stress.

Current status of biological control of introduced Phragmites in Canada: Insights from initial years of post-release monitoring and a larval density release experiment.

Introduced Phragmites (Phragmites australis australis (Cav.) Trin. Ex Steud.) is one of the most invasive plants in North America. To supplement existing management tools, a classical biological control program began in Canada in 2019 using two host-specific stem-boring moths, Archanara neurica (Hübner) and Lenisa geminipuncta (Haworth) (Lepidoptera: Noctuidae). In this article, we summarize the first three years of monitoring data for L. geminipuncta and A. neurica as biological control agents for introduced Phragmites. First, we assess agent presence and activity in the initial years post-release based on feeding damage from long-term monitoring data across 30 release sites initiated between 2019 and 2023. Second, we investigate the within-site distribution of agent feeding damage to improve future monitoring and agent collection from nurse sites. Third, we report the results of an experiment to determine optimal release densities of A. neurica larvae. We found agent feeding damage at 92% of initial release sites in the first year and agent activity persisted at all of these sites into years two and three post-release. Patterns of agent feeding damage suggest that the agents disperse quickly through the patch following release, favouring the interior area over the edges of introduced Phragmites stands. Finally, releasing intermediate densities of 40 A. neurica larvae per release point was more efficient than releasing either units of 20 or 80 larvae. The results of the first three years of monitoring are highly encouraging for the introduced Phragmites biological control program. Insights from these early monitoring results will be used to refine optimal release strategies, improve our ability to locate egg-bearing stems at nurse sites to facilitate the collection and redistribution of agents to new release locations, and inform protocols for longer-term monitoring of impacts on the target weed once agents are established.

Invasion stress mitigates climate stress in a brackish marsh amphipod

Abstract Organisms in coastal brackish ecosystems face not only highly variable environmental conditions, but the intensity and stochasticity of these environmental conditions are anticipated to increase due to climate change. While environmental changes are often presented unilaterally as stressors, there are some anthropogenic environmental transformations, such as the introduction of habitat forming plant species, that may mitigate physiological stress imposed by warming. In Suisun Marsh in the California Delta, native plant canopies allow light and heat to penetrate to the understory yet the canopies of the introduced Phragmites australis reed block out sunlight and heat for organisms living below. We set out to understand the physiological performance of mud‐dwelling invertebrates in this context: can invasion stress mitigate climate stress? We raised field collected Gammarus amphipods in the laboratory under simulated ‘native canopy’ and ‘Phragmites canopy’ temperature/light conditions based on data from our field environmental loggers. We assessed survival, body mass, fecundity, glycogen and protein content every 2 weeks from our lab population of amphipods. We found that amphipods raised under the Phragmites conditions had better survival, greater stores of protein, and similar body mass and stores of glycogen, which could positively impact available food resource quality for juvenile fishes. We support this with field data showing higher use of Phragmites canopies by amphipods, especially in the water column, across the year of sampling. Synthesis and applications: Understanding the potential benefits of Phragmites as climate stress refugia can inform management decisions around its mitigation in future restoration.

Pragmatically Mapping Phragmites with Unoccupied Aerial Systems: A Comparison of Invasive Species Land Cover Classification Using RGB and Multispectral Imagery

Unoccupied aerial systems (UASs) are increasingly being deployed in coastal environments to rapidly map and monitor changes to geomorphology, vegetation, and infrastructure, particularly in difficult to access areas. UAS data, relative to airplane or satellite data, typically have higher spatial resolution, sensor customization, and increased flexibility in temporal resolution, which benefits monitoring applications. UAS data have been used to map and monitor invasive species occurrence and expansion, such as Phragmites australis, a reed species in wetlands throughout the eastern United States. To date, the work on this species has been largely opportunistic or ad hoc. Here, we statistically and qualitatively compare results from several sensors and classification workflows to develop baseline understanding of the accuracy of different approaches used to map Phragmites. Two types of UAS imagery were collected in a Phragmites-invaded salt marsh setting—natural color red-green-blue (RGB) imagery and multispectral imagery spanning visible and near infrared wavelengths. We evaluated whether one imagery type provided significantly better classification results for mapping land cover than the other, also considering trade-offs like overall accuracy, financial costs, and effort. We tested the transferability of classification workflows that provided the highest thematic accuracy to another barrier island environment with known Phragmites stands. We showed that both UAS sensor types were effective in classifying Phragmites cover, with neither resulting in significantly better classification results than the other for Phragmites detection (overall accuracy up to 0.95, Phragmites recall up to 0.86 at the pilot study site). We also found the highest accuracy workflows were transferrable to sites in a barrier island setting, although the quality of results varied across these sites (overall accuracy up to 0.97, Phragmites recall up to 0.90 at the additional study sites).