Grassland plant species occurring in extensively managed road verges are filtered by urban environments

Background: Urbanisation filters species in communities depending on their adaptability to conditions in built-up areas, especially in semi-natural habitats. Roadside vegetation is widespread along urban-rural gradients and is therefore a good place to study landscape-scale factors influencing plant community composition.

Aim: Our study aimed to assess how plant species distributions vary between urban and rural landscape contexts and to identify biological traits favoured in urban areas.

Methods: Presence/absence data for 63 indigenous common species were collected in 296 road verge patches distributed along the urban–rural gradient in three French cities. We investigated the effects of landscape composition on species assemblages and related individual species responses to urbanisation to functional traits associated with dispersal and persistence capacity.

Results: Many grassland species were negatively affected by increasing proportion of built-up areas in the landscape. Insect-pollination and high seed production appeared to be key traits favoured in grassland communities in urban areas, whereas dispersal modes were less related to plant distribution.

Conclusions: This study has demonstrated that urban filters affect common species of widespread, managed road verges. Better knowledge of the flora of these herbaceous roadsides may contribute to the conservation of common biodiversity within other grassland habitats found in urban areas.     

Experimental test of the ecosystem impacts of the keystone predator Triops cancriformis (Branchiopoda: Notostraca) in temporary ponds

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Carbon emission along a eutrophication gradient in temperate riverine wetlands: effect of primary productivity and plant community composition

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Crossing the threshold: an amphibian assemblage highly infected with Batrachochytrium dendrobatidis in the southern Brazilian Atlantic forest

The fungal infection caused by Batrachochytrium dendrobatidis (Bd) in amphibians is known to be lethal when infection intensity values exceed loads of 10,000 zoospores per individual. We investigated Bd infection intensity in 100 anurans of southern Brazil. Almost half of the individuals were infected and the intensity ranged from four to about 156,000 zoospore genomic equivalents. We found no clinical signs of chytridiomycosis and no evidence of mortality. However, we observed a reduction in the number of infected individuals with loads above 10,000 zoospores. This fact could be considered indirect evidence that individuals with high loads are removed from the population.     

Efficiency of nitrogen and phosphorus removal by six macrophytes from eutrophic water

Abstract

Increased nitrogen and phosphorus pollution causes eutrophication in water bodies. Using aquatic plants to remove nutrients from water is an attractive phytoremediation. It is a cost-effective, environment-friendly, and efficient way that reduces water body eutrophication by the plant. It is important to choose suitable macrophytes to remove excess N and P under different nutrient conditions. In this study, six macrophyte species (Polygonum orientale, Juncus effuses, Iris pseudocorus, Phragmites australis, Iris sanguinea, Typha orientalis) were tested. Simulation experiment was conducted under five N and P levels. The removal rate, relative growth rate, and the dynamic nutrition concentration of cultivated solution were investigated. Of all the treatment, a 23–95% reduction in N removal and a 29–92% reduction in P removal were recorded. The results showed I. sanguinea is a promising species to treat various eutrophic waters and the other five species can be used specifically to treat certain types of water. The data provided a theoretical guidance to plant species selection for phytoremediation of polluted water bodies for the purpose of water quality improvement around the different reservoir in northern China.     

Coupled Active Systems Encode an Emergent Hunting Behavior in the Unicellular Predator Lacrymaria olor

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Energetic implications of floodplain wetland restoration strategies for waterfowl

Modifications of the Illinois River and associated tributaries have resulted in altered hydrologic cycles and persistent river‐floodplain connections during the growing season that frequently impede the establishment of hydrophytic vegetation and have reduced value for migratory waterfowl and other waterbirds. To help guide floodplain restoration, we compared energetic carrying capacity for waterfowl in two wetland complexes along the Illinois River under different management regimes during 2012–2015. The south pool of Chautauqua National Wildlife Refuge (CNWR) was seasonally flooded due to a partial river connection and managed for moist‐soil vegetation. Emiquon Preserve was hydrologically isolated from the Illinois River by a high‐elevation levee and managed as a semipermanently flooded emergent marsh. Semipermanent emergent marsh management at Emiquon Preserve produced 5,495 energetic use‐days (EUD)/ha for waterfowl and other waterbirds across wetland cover types and years, and seasonal moist‐soil management at CNWR produced 6,199 EUD/ha in one of 4 years. At Emiquon Preserve, the aquatic bed cover type produced 9,660 EUD/ha, followed by 5,261 EUD/ha in moist‐soil, 1,398 EUD/ha in persistent emergent, 1,185 EUD/ha in hemi‐marsh, and 12 EUD/ha in open water cover types. At CNWR, the annual grass and sedge cover type produced 7,031 EUD/ha, followed by 5,618 EUD/ha in annual broadleaf and 1,305 EUD/ha in perennial grass cover types. Restoration of floodplain wetlands in isolation from frequent flood pulses during the growing season can produce hemi‐marsh and aquatic bed vegetation communities that provide high‐quality habitat for waterfowl and which have been mostly eliminated from large river systems in the Midwest, U.S.A.     

Cross‐taxon congruence of multiple diversity facets of freshwater assemblages is determined by large‐scale processes across China

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Livestock disturbances in Mediterranean temporary ponds: A mesocosm experiment with sheep manure and simulated trampling

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