Una aproximación al funcionamiento de los arroyos de montaña del norte de la Patagonia Andina

Patagonian Andes has Nothofagus forests as characteristic vegetation, which extends from 37° to 55° S. In particular, N. pumilio (lenga) is the most widely distributed species, both in Argentina and Chile, and as it is a deciduous species, it represents an important organic matter input to headwater streams. These streams are originated in high altitude mountains and drain the forest downstream. We have been studying the ecology of Challhuaco catchment, in the Northeast of Patagonian Andes, for more than a decade. These studies encompassed both structural and functional aspects of stream ecology, including nutrient and organic matter analysis along the catchment, and feeding relationship between the different components of food webs, from primary producers, leaf litter decomposers and benthic macroinvertebrates to top consumers, as the rainbow trout. In this review we aimed to gather and relate results of a catchment that may be used as a model to extrapolate to other Andean Patagonian catchments. Finally, we indicated some conflicts and threats to which these systems are exposed, to point out the aspects that should be incorporated into conservation policies including a more sustainable management of forestry and cattle raising.