CONICET | Buscador de Institutos y Recursos Humanos

The water quality ofwetlands is governed not only by natural variability in hydrology and other factors, but also by anthropogenic activities. Patagonia is a vast sparsely-populated inwhich ponds are a key component of rural and urban landscapes because they provide several ecosystemservices such as habitat forwildlife and watering for livestock. Integrating field-based and geospatial data of 109 ponds sampled across the region, we identified spatial trends and assessed the effects of anthropogenic and natural factors in pond water quality. The studied ponds were generally shallow, well oxygenated, with maximumnutrient values reported in sites used for live- stock breeding. TN:TP ratio values were lower than 14 in N90% of the ponds, indicating nitrogen limitation. Water conductivity decreased fromde east to the west, meanwhile pH and dissolved oxygen varied associated with the latitude. To assess Patagonian pondswater statuswerecommend themeasure of total suspended solids and total nitrogen in thewater, and evaluate themallín(wetlandvegetation) coverage in a 100mradius fromthe pond, since those featureswere significantly influenced by livestock landuse. To evaluate the relativeimportance of natural variability and anthropogenic influences as driving factors of water quality weperformed three gener- alized linearmodels (GLM) that encompassed the hydrology, hydroperiod and biome(to represent natural influ- ences), and land use (to represent anthropogenic influences) as fixed effects. Our results revealed that at the Patagonian scale, pondswater qualitywould be strongly dependent on natural gradients.Wesynthetized spatial patterns of Patagonian pond water quality, and disentangled natural and anthropic factors finding that the dom- inant environmental influence is rainfall gradient.