ENSO effects on primary productivity in Southern Atacama desert

摘要

In the winter-rain southern Atacama Desert of the Coquimbo Region of Chile,El Niño - Southern Oscillation (ENSO) events modulate primaryproductivity. In this region, there are important changes in wateravailability between La Niña (dry) and El Niño (rainy) years. Usinginter-annual comparisons of LANDSAT images from 30° to 31° Slatitude, we observed changes in primary productivity between dry and rainyyears at the regional level. There were also significant, negativecorrelations between productivity and elevation, with changes occurringfirst at low elevation during rainy years. The limiting factors to drylandvegetation primary productivity is different in regard to elevation. Rainduring an El Niño year is the main factor that explains the increase inprimary productivity at low elevation, while lower temperatures reduce anddelay the net primary productivity at mid elevation.