Temporal dynamics of invertebrate and aquatic plant communities at three intermittent ponds in livestock grazed Patagonian wetlands

Abstract

Ponds are recognized worldwide as biodiversity hotspots; nevertheless in Patagonia studies are still needed that reveal the composition and status of their communities. This paper analyses the temporal patterns of aquatic invertebrates and assesses the environmental factors that best predict the variation in community structure at three small intermittent ponds, subjected to ranching practices (summer stocking) in the Patagonian steppe. Variables identified as important in structuring community assemblages were related to environmental conditions (rainfall and water temperature), chemical features (conductivity and pH) and biotic factors (macrophyte coverage). During the connected phase only a small number of invertebrate species were present, in contrast to the 11 taxa that were frequent and abundant during the isolated period (Eucyclops chilensis, Hyalella curvispina and Rhionaeschna sp. were dominant). In this sequence the submersed Myriophyllum quitense and Lilaeopsis macloviana played a crucial role offering habitat and food resources. The present study provides valuable information that can contribute to minimizing the environmental damage and the development of strategies for the conservation of Patagonian wetlands.

Environmental Quality and Aquatic Invertebrate Metrics Relationships at Patagonian Wetlands Subjected to Livestock Grazing Pressures

“…Inspection of weather conditions a posteriori revealed that both sampling periods were comparable in terms of rain, air temperature, and wind [ 20 ]. Surveys were conducted in early summer, the optimal season for obtaining samples representative of local invertebrate diversity and consisting of mature, readily identifiable individuals [ 21 ]. Moreover, the natural recharge of pond at wetlands occurs during seasonal rainfalls in winter, and the local ranching practices involve rotating livestock to wetlands in summer for reproductive periods and weaning.…”

Is There a Pattern for Occurrence of Macrophytes in Polish Ponds?

“…Research conducted on ponds in Patagonia showed that the concentrations of nutrients were good indicators of the state and quality of water. The content of nutrients in ponds affected by sewage should be higher than in more isolated ponds [65].…”

Variabilidad estructural de la comunidad de macrófitas en un gradiente pluviométrico en la provincia de Chubut

“…Sobre la base de esas imágenes se seleccionó y muestreó un total de 20 lagunas someras (Tabla 1). Las lagunas fueron muestreadas en una única ocasión entre diciembre de 2013 y enero de 2014, ya que en la región resulta el período más apropiado para estudiar tanto la composición de las macrófitas (e.g., fenología y presencia de flores), como para estimar su abundancia (Epele and Miserendino 2015).…”