Influence of hydroclimatic conditions and anthropogenic activities on the water quality of a floodplain lake (Argentina) during a warm season.

Contamination of water bodies, associated with urbanization, agricultural, and industrial activities, is a serious environmental challenge, with particular concern about microbial pollution due to its public health implications. This study is aimed at evaluating the spatial and temporal variations in the microbiological and physicochemical quality of a floodplain lake used for recreational purposes, whose watershed has been disturbed by diverse anthropogenic activities. The results showed that, while the spatial variation of water quality principally depends on the basin characteristics, temporal variation of water quality depends on land uses, hydrological conditions, and climatic conditions.

Unravelling the influence of cattle stocking rate on the macroinvertebrate community of freshwater wetlands subjected to hydrological modifications in three hydroclimatic periods.

The Paraná River Delta in South America, a large wetlands macromosaic, faces threats from climate change, human activities like livestock intensification, and hydrological modifications driven by the construction of water management infrastructure to prevent flooding in productive lands. Macroinvertebrates, essential for wetland health, are affected by cattle-induced changes in water quality, nutrient enrichment, and trampling, posing challenges to the ecosystem's ecological balance and long-term survival of these organisms. In this study, we analyzed the impact of two categories of cattle stocking rates (low and high) on the taxonomic and functional structure of the aquatic macroinvertebrate community in freshwater marshes.

Effects of herbicides and fertilization on biofilms of Pampean lotic systems: A microcosm study.

We experimentally assessed the impact of the application of herbicides and fertilizers derived from agricultural activity through the individual and simultaneous addition of glyphosate, atrazine, and nutrients (nitrogen 'N' and phosphorus 'P') on the biofilm community and their resilience when the experimental factors were removed. We hypothesize that i) the presence of agrochemicals negatively affects the biofilm community leading to the simplification of the community structure; ii) the individual or simultaneous addition of herbicides and nutrients produces differential responses in the biofilm; and iii) the degree of biofilm recovery differs according to the treatment applied. Environmentally relevant concentrations of glyphosate (0.

Spatiotemporal patterns of multiple pesticide residues in central Argentina streams.

Pollution of surface waters is a global threat, with particular concern about pesticides due to their severe negative effects on ecosystem functioning and human health. The aims of this study were to identify the spatiotemporal patterns of water and sediment quality, and the key variables related to the variation in pesticide pollution (122 compounds), in headwater streams (surrounding land uses: crop or mixed crop-livestock systems) and floodplain streams (surrounding land uses: urban development or natural wetland) of the Paraná River basin in the central area of Argentina. We found significant differences in water and sediment quality related to local land uses among headwater streams, but not among floodplain streams.

Impacts of leaks and gas accumulation on closed chamber methods for measuring methane and carbon dioxide fluxes from tree stems.

Accurate measurements of methane (CH) and carbon dioxide (CO) fluxes from tree stems are important for understanding greenhouse gas emissions. Closed chamber methods are commonly employed for this purpose; however, leaks between the chamber and the atmosphere as well as gas accumulation, known as the concentration buildup effect, can impact flux measurements significantly. In this study, we investigated the impacts of concentration buildup and leaks on semi-rigid closed chamber methods.

Presence of spp. in a Mosaic of Wetlands Used for Livestock Raising under Differing Hydroclimatic Conditions.

Knowledge about the life cycle and survival mechanisms of leptospires in the environment is scarce, particularly regarding the environmental factors associated with their presence in ecosystems subject to livestock farming, where precipitation, seasonal floods, and river overflows could act as facilitators of leptospire dispersion. This study aimed to identify and study the presence of spp. in the Lower Delta of the Paraná River and describe the physical, chemical, and hydrometeorological conditions associated with their presence in wetland ecosystems impaired by livestock raising intensification.

Environmental heterogeneity determines the ecological processes that govern bacterial metacommunity assembly in a floodplain river system.

How diversity is structured has been a central goal of microbial ecology. In freshwater ecosystems, selection has been found to be the main driver shaping bacterial communities. However, its relative importance compared with other processes (dispersal, drift, diversification) may depend on spatial heterogeneity and the dispersal rates within a metacommunity.

Interactive effects of fish predation and sublethal insecticide concentrations on freshwater zooplankton communities.

Stresses imposed by insecticides and predators are possibly the most rigorous filters to which aquatic organisms are exposed in rivers and lakes associated with agricultural lands. However, their interactive effects on zooplankton communities are still unclear. This study elucidated the zooplankton community response to fish predation, the insecticide chlorpyrifos (CLP), and a combination of both factors, using a 30-day mesocosm experiment.