Water services in central Argentina: identifying priority areas for conservation

Abstract

The influence of landscape characteristics on dry season baseflow in mountain areas with a long dry season depends on a complex array of factors which need to be identified in order to prioritize landscapes for conservation of water provisioning services. Our objective was to detect which landscapes, as combinations of land cover types and topographical features are better suited to provide water during the dry season. We evaluated dry season water discharge (mm day1) and rainfall during three years in 16 small headwater catchments (1.1?3.5 km2) in the mountains of central Argentina. For each catchment we estimated landscape variables as the proportion of five land-cover units and eight topographic properties. We analyzed water discharge as a function of landscape variables using regressions. Both rainfall and water discharge declined from years 1 to 3, but differences in water discharge among catchments were larger than differences among years, and consistent throughout time. Dry season water discharge was always higher in catchments located in rugged landscapes, with a high proportion of deep valleys and rock outcrops as compared to catchments in gentle landscapes with a high proportion of plains and covered with grasslands. We conclude that conservation priorities toward rugged landscapes would optimize water provisioning services. Reducing present rates of soil loss in deep valleys and controlling their incipient invasion by woody aliens is especially important. In coincidence, rugged landscapes host a higher diversity of various taxa.