CONICET | Buscador de Institutos y Recursos Humanos

The water quality of wetlands is governed not only by natural variability in hydrology and other factors, but alsoby anthropogenic activities. Patagonia is a vast sparsely-populated in which ponds are a key component of ruraland urban landscapes because they provide several ecosystem services such as habitat for wildlife and wateringfor livestock. Integrating field-based and geospatial data of 109 ponds sampled across the region, we identifiedspatial trends and assessed the effects of anthropogenic and natural factors in pond water quality. The studiedponds were generally shallow, well oxygenated, with maximum nutrient values reported in sites used for livestockbreeding. TN:TP ratio values were lower than 14 in N90% of the ponds, indicating nitrogen limitation.Water conductivity decreased from de east to the west, meanwhile pH and dissolved oxygen varied associatedwith the latitude. To assess Patagonian pondswater status we recommend the measure of total suspended solidsand total nitrogen in the water, and evaluate the mallín (wetland vegetation) coverage in a 100mradius fromthepond, since those featureswere significantly influenced by livestock land use. To evaluate the relative importanceof natural variability and anthropogenic influences as driving factors of water quality we performed three generalizedlinearmodels (GLM) that encompassed the hydrology, hydroperiod and biome (to represent natural influences),and land use (to represent anthropogenic influences) as fixed effects. Our results revealed that at thePatagonian scale, ponds water qualitywould be strongly dependent on natural gradients. Wesynthetized spatialpatterns of Patagonian pond water quality, and disentangled natural and anthropic factors finding that the dominantenvironmental influence is rainfall gradient.

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