The study area is located in central Uruguay, in the Departments of
Durazno and Tacuarembó, along the Río Negro (Fig. 2). The land-use
and socio-economic indicators of the study area represent those commonly
found in the country. We defined a study area of about
1880 km2 in three small sub-catchments (micro cuenca) of the tributaries
of the Río Negro (sub-catchments 540, 543, 544 of the National
Watershed Classification System), including plantations that were