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.

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 and along roadsides throughout northern New York State. Its propensity to create monoculture stands in wetlands has resulted in intensive management in parts of its range, including central New York and Ontario and Quebec. The goal of this study was identifying the extent of infestations and to determine factors that promote the spread of purple loosestrife in order to determine best land use practices to reduce the spread of this highly invasive wetland plant." We attempted to answer several questions: What is the level of infestation along roadsides? Does mowing contribute to the spread? How do culverts under roadways influence the spread? Between mid-July and mid-August in 2017–2019, we mapped all infestations along 150 km (93 miles) of state highway north of the Adirondack Park and south of the St. Lawrence River using the Environmental Systems Research Institute (ESRI) Collector app. We mapped the size and locations of infestations, in addition to collecting information on the plants within 1 m, recording over 100 additional species. The results of our preliminary analysis revealed significant increase in the number of plants over the study time (P < 0.001), including several hundred more infestations than had previously been recorded. We did not find any evidence that mowing promotes the spread of loosestrife. There were many more individual infestations in ditches along highways, but much larger and denser infestations in wetlands (P = 0.003 in 2019). We observed that culverts, drainage conduits under roadways, frequently had purple loosestrife on both sides of the road. We also found that culverts appear to serve as corridors that promote the spread of purple loosestrife from one side of the road to the other. We recommend working with the local landowners and NYS Department of Transportation to contain the spread and continue to propagate and spread the biological control.

Constructed floating wetlands made of natural materials as habitats in eutrophicated coastal lagoons in the Southern Baltic Sea

Eutrophication remains an environmental challenge in lagoons along the Southern Baltic Sea. Floating islands planted with emergent macrophytes are an option to remove nutrients from eutrophicated waters. Furthermore, floating wetlands offer other ecosystem services such as the provision of habitats. Numerous scientific studies have been conducted; however most remain on the laboratory scale. This research explores the challenges associated with installations in coastal environments and focuses on sustainability of the island design, the habitat function as well as nutrient removal. Most floating wetland designs use polyethylene, polypropylene, polyurethane or polyvinyl alcohol foam to ensure the buoyancy. For this study an artificial polymer free island design was developed and tested. The floating constructions in the Darss-Zingst-Bodden-Chain were planted with native macrophytes which have the potential to act as ‘biodiversity-supplements’ to the adjacent coastal wetlands: Bolboschoenus maritimus, Carex acutiformis, Iris pseudacorus, Juncus effesus, Lythrum salicaria, Schoenoplectus lacustris, Typha latifolia. The chosen macrophytes survived fluctuating salinities. After three months the above-ground biomass was harvested and analyzed for the nutrient concentrations. Phosphorus concentrations were highest in L. salicaria and nitrogen in I. pseudacorus. Video monitoring and field observations were applied in order to observe animals. Birds did not use the floating wetlands as breeding grounds, but the grey heron (Ardea cinerea) was a common visitor for foraging. Especially surprising was the large amount of juvenile eels (Anguilla anguilla). A diverse and large root network below the floating islands boosts not only nutrient removal but serves as a shelter and refuge for fish such as the endangered eel.

How Waterlogged Conditions Influence the Nitrogen Removal Performance in a Micro Constructed Wetland

Growing populations and industrialization have led to raised wetland ecosystems nitrogen(N) loads. A micro constructed wetland planted with Lythrum salicaria L treating an artificial wastewater was used to investigate the short-term variations in the plant biomass and the removal efficiency of N. Our results showed that the biomass of Lythrum salicaria L. increased rapidly 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 concentration of TN in soil and effluent. Under different waterlogged conditions, the removal rates of TN in the water were all more than 60%, providing a reference for waterlogged conditions used in wetland eutrophication restoration.

Antimicrobial and Antioxidant Effects of Aqueous Extract of Lythrum Salicaria

Introduction: The spread of drug-resistant pathogenic strains and the increase of free radicals in food sources are major health problems worldwide. The side effects of chemical drugs have led the researchers to use natural products. In this study, the antimicrobial and antioxidant effects of leaf extract of Lythrum Salicaria have been investigated. Methods: This research was a basic experimental study. The aqueous extract of Lythrum Salicaria leaf was prepared by maceration method. Antimicrobial effects of the extract were evaluated by disk diffusion method. The antioxidant properties of extract were determined by DPPH and iron reducing power methods. In addition, the amounts of phenol, flavonoid and flavonol were assayed by Folin-ciocalteu and Aluminum chloride methods, respectively. Data were compared by analysis of variance (ANOVA) using SPSS version 16 software. Results: All of the studied strains were sensitive to the aqueous extract of Lythrum Salicaria leaf except E. coli. The mean zones of inhibition were due to the extracts on the tested bacteria obtained in ranging from 12.67 to 24.67 mm. Statistical analysis showed a significant relationship between the mean diameters of growth inhibition zone and increased extract concentrations (P < 0.001). The total phenolic content, total flavonoid content and total flavonol content values of extract were determined as 36.53 ± 1.27 mg gallic acid per gram extract, 5.2 ± 0.4 mg quercetin per gram extract and 20.8 ± 0.95 quercetin per gram extract, respectively. Conclusion: Extract of Lythrum Salicaria can be a good alternative to common antibiotics resistant. The acceptable antioxidant effects of the Lythrum Salicaria extract can be introduced it as an inhibitor of diabetes and cancer.

Evidence for continent-wide convergent evolution and stasis throughout 150 years 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. While field experiments have demonstrated that adaptive evolution can occur quickly, our understanding of the duration and geographical extent of contemporary evolution in natural systems remains limited. 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 estimate genetic differences among phenotypes observed in natural history collections. Reconstructing 150 years of evolution in Lythrum salicaria (purple loosestrife) as it invaded across 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 degrees of latitude. We find that phenology evolves rapidly and repeatedly along parallel climatic gradients during the first century of evolution. However, the rate of microevolution stalls thereafter, recapitulating macroevolutionary stasis observed in the fossil record. Our study demonstrates why preserved specimens are a critical resource for understanding limits to evolution in natural. Our results show predictability of evolution emerging at a continental scale across 15 decades of rapid, adaptive evolution.

Lythrum salicaria (purple loosestrife).

L. salicaria, an Old World native, is a highly invasive species of wetlands in North America, beginning to spread rapidly about 140 years after its accidental introduction around 1800. It is a very variable species with an ability to occupy numerous habitats and substrates with the exception of dry places. Its spread and persistence in ecosystems is supported by very high seed production, a vigorous and persistent root system and rapid growth. It is an invasive species and/or noxious weed in almost all states and provinces of Canada and the USA where it is a serious threat to many sensitive wetland ecosystems.

Uptake Kinetics of \({\text{NH}_{4}^{+} }\), \({\text{NO}_{3}^{-} }\) and \({\text{H}_{2}\text{PO}_{4}^{-} }\) by Typha orientalis, Acorus calamus L., Lythrum salicaria L., Sagittaria trifolia L. and Alisma plantago-aquatica Linn

The emergent plants may differ in their capacity to assimilate nutrients from eutrophic water bodies, so the utilization of suitable emergent plants is the key part for successful restoration of shallow eutrophic lakes and rivers. This research applied the depletion method to study the kinetics of uptake of nutrient (H2PO4−, NH4+, NO3−) in different nutrient stresses by the five emergent aquatic plants (Acorus calamus L., Typha orientalis, Lythrum salicaria L., Sagittaria trifolia L., Alisma plantago-aquatica Linn) in the riverine zones of Dashi River (39°30′–39°40′ N, 115°59′–116°5′ E), a shallow eutrophic river located in Fangshan District, Beijing. The results showed that at the three phosphorus levels, A. calamus and A. plantago-aquatica had the highest maximum uptake rate values for NH4+ under low to moderate phosphorus conditions, and high phosphorus, respectively. T. orientalis had the highest maximum uptake rate values for NO3− at all phosphorus concentrations, while the Michaelis-Menten constant values of L. salicaria and A. plantago-aquatica were smaller. At the three nitrogen levels, the maximum uptake rate values for H2PO4− were the greatest for A. plantago-aquatica at the low to moderate nitrogen levels and L. salicaria at high levels. Meanwhile, T. orientalis and L. salicaria had the smallest Michaelis-Menten constant values. In this study, nitrogen microbial transformations, such as nitrification, denitrification and their coupling were not measured and their role in measuring kinetics was not assessed. Thus, achieved results shall be considered as a synthesis of several processes mediated by plants, a theoretical guidance to the selection of plant species for phytoremediation of polluted water bodies with different nutrient stresses for quality improvement around the diverse rivers in Haihe River basin.