Lythrum Salicaria Research Articles

Detection of Aquatic Invasive Plants in Wetlands of the Upper Mississippi River from UAV Imagery Using Transfer Learning

Aquatic invasive plants (AIPs) are a global threat to local biodiversity due to their rapid adaptation to the new environments. Lythrum salicaria, commonly known as purple loosestrife, is a predominant AIP in the upper Midwestern region of the United States and has been designated as a deadly threat to the wetlands of this region. Accurate estimation of its current extent is a top priority, but regular monitoring is limited due to cost-, labor-, and time-intensive field surveys. Therefore, the goal of the present study is to accurately detect purple loosestrife from very high-resolution UAV imagery using deep neural network-based models. As a case study, this study implemented U-Net and LinkNet models with ResNet-152 encoder in the wetlands of the upper Mississippi River situated in La Crosse County, Wisconsin. The results showed that both models produced 88–94% training accuracy and performed better in landscapes that were occupied by smaller, disaggregated, and more equitably distributed purple loosestrife. Furthermore, the study adopted a transfer learning approach to implement a trained purple loosestrife model of the first study site and implemented it for the second study site. The results showed that the pre-trained model implementation generated better accuracy in less than half the time of the original model. Therefore, the transfer learning approach, if adapted efficiently, can be highly beneficial for continuous monitoring of purple loosestrife and strategic planning for application of direct biocontrol measures.

Названия растений как часть поэтического лексикона (на материале «Словаря языка русской поэзии ХХ века»)

The article discusses the features of the lexicographic description of plant names (phytonyms) in the dictionary of the poetic language. The Dictionary of the Language of the Twentieth Century Russian Poetry, describing the lexicon of ten outstanding authors of the Silver Age (I. Annensky, A.Akhmatova, A. Blok, S. Yesenin, M. Kuzmin, O. Mandelstam, V. Mayakovsky, B. Pasternak, V. Khlebnikov, M. Tsvetaeva), includes more than 500 such lexical items. Plants representation in the poetic language differs significantly. On the one hand, the names of fundamentally important, culturally significant plants belong to the core of the poetic lexicon: these are mainly trees (birch, oak, willow, pine), fruit trees or shrubs and their fruits (cherry, raspberry, apple tree/apple), as well as roseand some other flowers (stock, lily, violet). These plant names usually receive a poetic interpretation, cf. iva ‘willow ’, and ivka ‘little willow ’, ivnyak ‘willow shrubs’, iva-providitsa ‘willow-seer’. On the other hand, the poetry of the Silver Age is characterized by close attention to the real, material world, and rarer lexemes are organically included in the poetic text. These are the names of garden and wild flowers (anemone, aster, marigolds, cornflower, carnation), common names (Ivan-da-Maria‘cow wheat’, kashka‘clover’, lubka‘butterfly orchids’, weeping-grass‘purple loosestrife’), a kind of non-poetic names (turnip, elder, box-thorn, carrot, radish). The Russian National Corpus allows us to trace the variability of the poetic lexicon: a number of names (primarily specific, common names) first appear in the poetry of the Silver Age, other names eventually leave the lexicon.

Is endozoochoric seed dispersal by large herbivores an evolutionary adaptation? Revisiting the Janzen's ‘Foliage is the fruit’ hypothesis

Many plant species develop fruits to attract animals that will eat them and then disperse the seeds. However, there are many plant species, whose seeds are dispersed endozoochorically, but their fruits are not particularly attractive to animals. The “Foliage is the fruit” (FF) hypothesis proposes that entire biomass of the plant exists to encourage herbivores to eat it, in order to enhance seed intake and dispersal (Janzen, 1984).We tested the FF hypothesis by combining the results from the greenhouse seedling emergence method (GR) and DNA-metabarcoding of plant remnants in faeces of European moose (Alces alces L.). We processed 665 samples by the GR and 429 by the MB method, hypothesizing that if the safe passage of seeds through the gut of a large herbivore is the result of an evolutionary adaptation to endozoochoric dispersal, then the species composition of plants revealed by the two methods should largely overlap and the abundance of seedlings revealed by the GR method should be positively correlated in time with the read abundance of DNA of the same species. The large discrepancy between the lists of species detected by DNA metabarcoding and the GR method argues against the FF hypothesis. However, in the case of Urtica dioica, Lysimachia vulgaris and Lythrum salicaria, some clues of evolutionary adaptation to endozoochoric dispersal were revealed for: 1) their foliage is attractive to herbivores; 2) seeds are small, rounded in shape, yielded in large numbers and pass safely through the herbivore's gut; 3) the abundance of seeds (seedlings) was significantly and strongly influenced by the abundance of the plant biomass (DNA reads) in dung samples; 4) peaks in seed abundance and biomass consumption coincided in time. However, it should be considered that moose's diet is mostly composed of woody browse, which makes this animal not an optimal model for testing the Janzen's hypothesis and studies on typical grazers are needed in this respect.

Citizen science and land use data provide insight into the invasive riparian plant composition of the Hudson River Valley watershed

AbstractInvasive plants in the riparian zone can negatively affect the characteristics and quality of a watershed. To support the development of a watershed management plan and foster public appreciation of the value of the riparian zone, Mohonk Preserve established a volunteer monitoring program surveying sites for invasive species. Between 2017 and 2019, citizen scientists repeatedly surveyed 20 sites in the Hudson River Valley in New York for 10 invasive plant species: purple loosestrife (Lythrum salicaria L.), common reed [Phragmites australis (Cav.) Trin. ex Steud], multiflora rose (Rosa multiflora Thunb.), garlic mustard [Alliaria petiolata (M. Bieb.) Cavara & Grande], dame’s rocket (Hesperis matronalis L.), Japanese knotweed (Polygonum cuspidatum Siebold & Zucc.), wineberry (Rubus phoenicolasius Maxim.), barberry (Berberis spp.), Japanese stiltgrass [Microstegium vimineum (Trin.) A. Camus], and Asiatic bittersweet (oriental bittersweet, Celastrus orbiculatus Thunb.). We found that the number of target species detected was higher on sites closer to paved roads and with increasing drainage area size, while lower with higher percentages of forested land in the basin. Our analysis results highlight variation in the presence of target invasive species across the Hudson River Valley region, highlighting sites and areas to monitor for future introductions and take action to prevent species’ invasions. Our results highlight differences in the most relevant abiotic factors for hydrophytes and non-hydrophyte species, underscoring the importance of considering species’ life-history traits before the development of management plans for invasive plant species in the riparian zone. Our case study of community-collected data in the Hudson River Valley region using a relatively simple monitoring protocol can provide a road map for other regions fostering volunteer engagement with invasive plants.

Green Synthesis and Characterization of Silver Nanoparticles Using a Lythrum salicaria Extract and In Vitro Exploration of Their Biological Activities.

This research describes an eco-friendly green route for the synthesis of AgNPs using an aqueous extract of Lythrum salicaria. Taguchi design was used to optimize the synthesis method, taking into account various working conditions. The optimum parameters were established using a 3 mM AgNO3 concentration, a 1:9 extract:AgNO3 volume ratio, a pH value of 8, 60 ℃ temperature, and 180 min reaction time. The synthesized AgNPs were characterized using UV-Vis and FTIR spectroscopy, and TEM and EDX analysis. The SPR band at 410 nm, as well as the functional groups of biomolecules identified by FTIR and the EDX signals at ~3 keV, confirmed the synthesis of spherical AgNPs. The average AgNPs size was determined to be 40 nm, through TEM, and the zeta potential was −19.62 mV. The antimicrobial assay showed inhibition against S. aureus and C. albicans. Moreover, the results regarding the inhibition of lipoxygenase and of peroxyl radical-mediated hemolysis assays were promising and justify further antioxidant studies.

Plant selection for roadside rain gardens in cold climates using real-scale studies of thirty-one herbaceous perennials

Plant selection for rain gardens along streets and roads in cold climates can be complicated, as the plants are subjected to combined stresses including periodic inundation, de-icing salts, road dust, splashes of water from the road, freezing and thawing of soil, and periods with ice cover during the winter. The purpose of this study was to identify species suited to grow in these conditions and determine their optimal placement within roadside rain gardens. Thirty-one herbaceous perennial species and cultivars were planted in real-scale rain gardens in a street in Drammen (Norway) with supplemental irrigation, and their progress was recorded during the following three growing seasons. The study highlights considerable differences between species’ adaptation to roadside rain gardens in cold climates, especially closest to the road. Some candidate species/cultivars had a high survival rate in all rain garden positions and were developed well. These were: Amsonia tabernaemontana, Baptisia australis, Calamagrostis × acutiflora ‘Overdam’, Hemerocallis ‘Camden Gold Dollar’, Hemerocallis ‘Sovereign’, Hemerocallis lilioasphodelus, Hosta ‘Sum & Substance’, Iris pseudacorus and Liatris spicata ‘Floristan Weiss’. Other species/cultivars appeared to adapt only to certain parts of the rain garden or had medium tolerance. These were: Calamagrostis brachytricha, Carex muskingumensis, Eurybia × herveyi ‘Twilight’, Hakonechloa macra, Hosta ‘Francee’, Hosta ‘Striptease’, Liatris spicata ‘Alba’, Lythrum salicaria ‘Ziegeunerblut’, Molinia caerulea ‘Moorhexe’, Molinia caerulea ‘Overdam’, and Sesleria autumnalis. Species/cultivars that showed high mortality and poor development at all rain garden positions should be avoided in roadside cold climate rain gardens. These include Amsonia orientalis, Aster incisus ‘Madiva’, Astilbe chinensis var. tacquettii ‘Purpurlanze’, Chelone obliqua, Dryopteris filix-mas, Eurybia divaricata, Geranium ‘Rozanne’, Helenium ‘Pumilum Magnificum’, Luzula sylvatica, Polygonatum multiflorum and Veronicastrum virginicum ‘Apollo’. The study also found considerable differences between cultivars within the same species, especially for Hosta cvv. and Liatris spicata. Further investigations are needed to identify the cultivars with the best adaption to roadside rain gardens in cold climates.

Removal effects of aquatic plants on high-concentration phosphorus in wastewater during summer

Aquatic plants are widely used in depth treatment of wastewater; however, the phosphorus (P) removal mechanisms of aquatic plants at high temperatures in summer are not well understood. Eight aquatic plants, including two floating species (Ludwigia peploides and Hydrocharis dubia) and six emergent species (Lythrum salicaria, Sagittaria sagittifolia, Canna indica, Sparganium stoloniferum, Rotala rotundifolia, and Ludwigia ovalis), were treated with five P solutions (3.0, 3.5, 4.0, 4.5, and 5.5 mg L−1) for 5 weeks in a greenhouse during summer at air temperatures ranging from 25 to 35 °C. H. dubia, L. peploides, L. salicaria, and S. sagittifolia showed high water P removal efficiencies (exceeded 95%). Furthermore, their corresponding residual P concentrations in water were almost lower than the limit value of 0.2 mg L−1 of Grade III in the Chinese Environmental Quality Atandards for Surface Water (GB3838-2002). Plants have different water P removal paths. For example, H. dubia enriched more P with water P concentration increasing significantly. As the culture time increased, the water pH fluctuated significantly in the fall, and then H. dubia used the produced H+ enrich P. L. peploides did not enrich P, but proliferated rapidly, to remove P from water by increasing its fresh weight (FW). L. salicaria and S. sagittifolia showed two paths of enrich-P and FW increase. During the growth process of L. salicaria, the stem diameter and leaf length increased with an increase in P concentration in water or plant or both; however, the height and root length of L. peploides were reduced. Moreover, SOD and CAT activities responded to high P concentrations in water or high temperatures or both, which protected against oxidative damage. These findings could offer theoretical foundation and practical guidance for selection of aquatic plant species in depth treatment of wastewater during summer.

Water Purification Effect of Ecological Floating Bed Combination Based on the Numerical Simulation

The Wuqing urban section of the North Canal Basin, Tianjin, is a significant gathering place for multisource pollution, showing the characteristics of a stagnant water body supplied by unconventional water sources. With the development of the economy and society, the water quality of the Wuqing urban section of the North Canal Basin, Tianjin, has been seriously polluted due to the discharge of sewage outlets and the influx of nonpoint source pollution from farmland. In this study, based on the results of special water experiments, a two-dimensional hydrodynamic water quality model was constructed. The concentrations of ammonia nitrogen (NH3-N), total phosphorus (TP), and chemical oxygen demand (COD) in the study area were simulated, and the model parameters were calibrated and verified with the measured values. Based on the model verification, the water quality improvement scheme of the ecological floating bed with different plant ratios was set up to simulate the water quality. The research results showed that the average concentrations of NH3-N, TP, and COD decreased by 10.4%, 15.7%, and of d 26.3%, respectively, after the ecological floating bed was arranged. During model parameter calibration and validation, the RMSE ranges of NH3-N, TP, and COD were 0.09~0.22 mg/L, 0.00~0.02 mg/L, and 0.37~2.42 mg/L, respectively. Other statistical indicators are also within a reasonable range, and the model accuracy and reliability are high. The simulation results of different scenarios showed that the optimal ratio of ecological floating bed plants was 700 m2 of Scirpus validus Vahl and 700 m2 of Canna in zone 1 of the floating bed combination, 430 m2 of Scirpus validus Vahl, and 170 m2 of Iris in zone 2 of the floating bed combination, and 200 m2 of Iris and 200 m2 of Lythrum salicaria in zone 3 of the floating bed combination. This study can provide a theoretical basis for the sustainable development of water purification in the North Canal. It can also provide a model approach for the implementation of river water purification schemes, exemplified by the North Canal.

Dissolved organic matter derived from aquatic plants in constructed wetlands: Characteristics and disinfection byproducts formation

Constructed wetlands are used to improve water quality in the drinking water sources, but aquatic plants planted in constructed wetlands may be a source of disinfection by-product (DBP) precursors. This study explored the characteristics of aquatic plant-derived dissolved organic matter (DOM) and DBP formation in micro-polluted raw water treated by constructed wetlands. A simulated surface flow wetland (SSFW) planted with the typical aquatic plants Lythrum salicaria and Acorus calamus was studied. Raw water, control samples, effluent, and Suwannee River natural organic matter (SRNOM) were analyzed. via ultraviolet-visible (UV-Vis) spectroscopy, three-dimensional excitation emission matrix (3D-EEM) fluorescence combined with a parallel factor (PARAFAC) analysis, liquid chromatography-organic carbon detection (LC-OCD), principal component analysis (PCA), and other detection and analysis methods. A DBP formation potential (DBPFP) index was also constructed. Treatment by the SSFW increased the effluent dissolved organic carbon (DOC), UV254, trihalomethane formation potential (THMFP), haloacetic acid formation potential (HAAFP) by 72.2%, 171.4%, 83.7% and 88.6%, respectively. Planting aquatic plants in surface wetlands will negatively affect the water quality of micro-polluted raw water, with the plants being an important source of increased DBP precursors in wetland effluent. The effluent properties were similar to those of SRNOM, and had a higher degree of aromatization and larger molecular weight than raw water. The increased DBP precursors were mainly fulic acid and humus with higher aromatic and molecular weight, which derived from the growth and metabolism of aquatic plants. Humic substances (HS) accounted for the highest proportion of DOM in this study, with the average molecular weight of HS increasing from 648 to 698 g·mol−1 as the DOM content increased. Results from this study are particularly applicable to the establishment of constructed wetlands planted with aquatic plants in the drinking water sources, and the DOM derived from aquatic plants in constructed wetlands may be important precursors in the subsequent water disinfection process.

Heavy metals distribution and accumulation characteristics of 16 species plants on ecological floating-bed

Distribution and accumulation characteristics of copper (Cu), zinc (Zn), mercury (Hg), and lead (Pb) in the aerial and underground parts of 16 species of plants on ecological floating-bed were studied in the present study, and they showed significant differences. Most translocation factors for Cu, Zn, Hg, and Pb were smaller than 1. Coleus blumei had a considerable absorption and accumulation effect on Zn, Hg, and Pb; Hylotelephium erythrostictum had a good absorption and accumulation effect on Zn and Hg. Arundo donax var. versicolor, Lythrum salicaria, and Iris pseudacorus which had remarkable absolute accumulation in the aerial part due to their massive biomass, and were expected to have a promising prospect in applying floating-bed technology.

Evidence for continent-wide convergent evolution and stasis throughout 150 y of a biological invasion

The extent to which evolution can rescue a species from extinction, or facilitate range expansion, depends critically on the rate, duration, and geographical extent of the evolutionary response to natural selection. Adaptive evolution can occur quickly, but the duration and geographical extent of contemporary evolution in natural systems remain poorly studied. This is particularly true for species with large geographical ranges and for timescales that lie between “long-term” field experiments and the fossil record. Here, we introduce the Virtual Common Garden (VCG) to investigate phenotypic evolution in natural history collections while controlling for phenotypic plasticity in response to local growing conditions. Reconstructing 150 y of evolution in Lythrum salicaria (purple loosestrife) as it invaded North America, we analyze phenology measurements of 3,429 herbarium records, reconstruct growing conditions from more than 12 million local temperature records, and validate predictions across three common gardens spanning 10° of latitude. We find that phenological clines have evolved repeatedly throughout the range, during the first century of evolution. Thereafter, the rate of microevolution stalls, recapitulating macroevolutionary stasis observed in the fossil record. Our study demonstrates that preserved specimens are a critical resource for investigating limits to evolution in natural populations. Our results show how natural selection and trade-offs measured in field studies predict adaptive divergence observable in herbarium specimens over 15 decades at a continental scale.

Physical, mechanical, and bioactive properties of edible film based on sodium alginate enriched with Lythrum salicaria L. extract

An active film was developed by incorporating Lythrum salicaria L. ethanol extract (LSE) into sodium alginate at concentrations of 0.5, 1.0, 1.5, and 2.0% v/v. The effects of LSE on the microstructure and physicochemical and bioactive properties of the films were evaluated. The ABTS antioxidant capacity of film samples was found to be 7.56–160.61 μmol TE/mg film, and the DPPH radical scavenging capacity was estimated to be 2.51%–38.44%. Films containing LSE showed remarkable antibacterial activity against both gram-positive and gram-negative strains. Moreover, it was also determined during the 14-day storage of raw ground meat samples under refrigerator conditions that, in comparison to the control films, the LSE-added active film samples were more effective on the microbiological characteristics of the product. It was determined that, in samples with LSE addition rate exceeding 0.5%, extract was not homogeneously distributed within the polymer matrix and decreased the tensile strength. Practical applications The presented study provides elaborate characterization analysis of the edible film to prove the effectiveness of using herbal extract incorporated active edible films for shelf life extension and packaging of raw meat. It was found that, in relation with the amount of LSE additive in films, the hydrophilic character of films increased, and it increased the biodegradability of film in the soil. In conclusion, it can be stated that sodium alginate-based edible films enriched with LSE have the potential of use in food packaging.

Mapping the purple menace: spatiotemporal distribution of purple loosestrife (Lythrum salicaria) along roadsides in northern New York State

Purple loosestrife (Lythrum salicaria L.) is an invasive, herbaceous plant, frequently found in wetlands, creating monoculture stands, resulting in intensive management strategies in central New York, Ontario, and Quebec. The goal of this study was to identify the extent of infestations and to investigate factors that promote the spread of purple loosestrife. We attempted to answer several questions regarding level of infestation, connection to mowing, and influence of culverts. During flowering season in July and August, 2017–2019, we mapped infestations along 150 km (93 miles) of state highway between the Adirondack Park and the St. Lawrence River using the ESRI Collector app. The results of our preliminary analysis revealed significant increase in the number of plants (P < 0.001). In addition, a linear correlation analysis demonstrated a higher loosestrife density with an increase in plant species richness and a decrease in the distance to the closest infestation and wetland (P < 0.001 each). We found no statistical evidence that mowing promotes the spread of loosestrife. As expected, there were more individual infestations in highway ditches, but larger and denser infestations in wetlands (P = 0.003 in 2019). Culverts enable purple loosestrife to spread underneath highways and should be managed to prevent spread.

Bioremediation of 27 Micropollutants by Symbiotic Microorganisms of Wetland Macrophytes

Background: Micropollutants in bodies of water represent many challenges. We addressed these challenges by the application of constructed wetlands, which represent advanced treatment technology for the removal of micropollutants from water. However, which mechanisms specifically contribute to the removal efficiency often remains unclear. Methods: Here, we focus on the removal of 27 micropollutants by bioremediation. For this, macrophytes Phragmites australis, Iris pseudacorus and Lythrum salicaria were taken from established wetlands, and a special experimental set-up was designed. In order to better understand the impact of the rhizosphere microbiome, we determined the microbial composition using 16S rRNA gene sequencing and investigated the role of identified genera in the micropollutant removal of micropollutants. Moreover, we studied the colonization of macrophyte roots by arbuscular mycorrhizal fungi, which are known for their symbiotic relationship with plants. This symbiosis could result in increased removal of present micropollutants. Results: We found Iris pseudacorus to be the most successful bioremediative system, as it removed 22 compounds, including persistent ones, with more than 80% efficiency. The most abundant genera that contributed to the removal of micropollutants were Pseudomonas, Flavobacterium, Variovorax, Methylotenera, Reyranella, Amaricoccus and Hydrogenophaga. Iris pseudacorus exhibited the highest colonization rate (56%). Conclusions: Our experiments demonstrate the positive impact of rhizosphere microorganisms on the removal of micropollutants.

RELATIONSHIP BETWEEN GENETIC AND ENVIRONMENTAL CHARACTERISTICS OF LITHUANIAN POPULATIONS OF PURPLE LOOSESTRIFE (LYTHRUM SALICARIA)

The present study evaluated genetic diversity of Lithuanian populations of Lythrum salicaria in relation to parameters of riparian environment. Growing along Nemunas, Seaside and Lielupė river basins, 15 populations were examined using amplified fragment length polymorphism markers. Molecular data were related to the river basins, type of land use and cover, natural vice versa regulated fragments of the rivers. Population mean genetic diversity parameters were as follows: percentage of polymorphic loci (57.2), expected heterozygosity (0.183), polymorphismc information content (0.218). Mantel test revealed correlation (R2 = 0.0986, p = 0.01) between genetic and geographic distance of populations. Greater genetic diversity within, rather than among populations (ΦPT = 0.213) was observed. According to the Bayesian clustering, studied populations are admixtures of two gene pools. Analysis of molecular variance revealed significant differentiation between populations belonging to distinct river basins, between populations from natural vs. regulated fragments of the rivers.

Using eDNA presence/non‐detection data to characterize the abiotic and biotic habitat requirements of a rare, elusive amphibian

AbstractThe environmental DNA (eDNA) approach has already been established as a valuable tool for the detection and monitoring of rare and elusive species. However, its application is not limited to assessing whether or not a species is present in a given area. In this study, we collected environmental data from 48 aquatic locations that had previously been investigated in an eDNA‐based study. We sought to determine the abiotic and biotic factors that could explain the presence or non‐detection of Hula painted frog DNA at those locations, in order to characterize this rare species’ little studied habitat requirements. We found that the detection probability of this species decreased substantially with increasing phosphorus loads as well as in the presence of the wetland plant Lythrum salicaria. By contrast, the detection probability increased markedly when Phragmites australis or Ludwigia stolonifera constituted part of the dominant aquatic vegetation. Our results expand the knowledge on this elusive frog species and contribute valuable information for future habitat restoration plans. They further show that eDNA data can also be used to characterize the putative habitats of species where such data are scarce or even totally lacking.

Новая ассоциация Phragmitetum altissimi ass. nov. (Phragmito-Magnocaricetea Klika in Klika et Novák 1941) из европейской части России и Западной Сибири

Новая ассоциация Phragmitetum altissimi ass. nov. (Phragmito-Magnocaricetea Klika in Klika et Novák 1941) из европейской части России и Западной Сибири

Effect of zinc on phytoremediation potential and carbonic anhydrase and polyphenol oxidase activities of Lythrum salicaria L.

Effect of zinc on phytoremediation potential and carbonic anhydrase and polyphenol oxidase activities of Lythrum salicaria L.

How to remove expansive perennial species from sedge-dominated wetlands: results of a long-term experiment in lowland river valleys

Grasslands belong to valuable ecosystems facing, all over Europe, a drastic decline in their range and loss of species diversity. Severe floristic transformation may result from the cessation of traditional low-input agricultural use, and consequently, the massive spread of perennial herbs and tall grasses. Invaders can quickly form dense stands and displace endemic vegetation, which results in a nearly complete turnover of phytocenoses. In European protected areas, the only legally acceptable means for suppressing alien species and native dominants within protected areas are biological methods and mowing. We investigated the effect of cutting on the presence of three megaforbs: Lysimachia vulgaris, Lythrum salicaria, and Filipendula ulmaria in fen meadows. We hypothesized that long-term, systematic management mimicking a traditional agricultural practice, would suppress the expansion of megaforbs. Management effectively stopped Lysimachia vulgaris only in marshes, where groundwater in the growing season fell deeper than 50 cm. Coverage of Lythrum salicaria fluctuated over the years, while Filipendula ulmaria did not give in to mowing pressure; on the contrary, it increased its coverage in some places. In light of the results of the long-term experiment, we conclude that mowing appeared to be low effective in preventing the spread of tall perennials. It was likely that indirect factors caused the local withdrawal of megaforbs, i.e., mowing-driven stimulation of other species’ development (e.g., Carex spp., Phragmites) that outcompete Lysimachia vulgaris.

How Waterlogged Conditions Influence the Nitrogen Dynamics in a Soil–Water–Plant System: Implications for Wetland Restoration

Growing populations and industrialization have led to increased nitrogen (N) loads in wetland ecosystems. A micro-constructed wetland planted with Lythrum salicaria L. to treat artificial wastewater was used to investigate the short-term variations in the plant biomass and dynamics of total nitrogen (TN) content. Our results showed that the biomass of Lythrum salicaria L. rapidly increased during the experiment due to their extensive root system and vigorous spread, and waterlogged conditions had little effect on the relationship between biomass and the TN content in soil and effluent. Under different waterlogged conditions, the TN removal rates in the water were all greater than 60%, providing a reference for the waterlogged conditions used in wetland eutrophication restoration.