Regional patterns and controls of ecosystem salinization with grassland afforestation along a rainfall gradient

NOSETTO, M D; JOBBÁGY, E G; TÓTH, T; JACKSON, R

GLOBAL BIOGEOCHEMICAL CYCLES

American Geophysical Union

Año: 2008 vol. 22 p. 1 - 12

0886-6236

Vegetation change affects water fluxes and influences the direction and intensity of salt exchange between ecosystems and groundwater. In some conditions it can also lead to an intense accumulation of salts in soils and aquifers, as has been documented for the conversion of native grassland to tree plantations in the plains of Argentina, Hungary and Russia. In this paper we present a hierarchical framework to predict salt accumulation following vegetation change that is based on climatic, hydrogeological and biological factors. We evaluated this spatially explicit framework in temperate South America using a network of 32 pairs of adjacent plantation and grassland stands studied with detailed field measurements and remotely sensed imagery from MODIS.Our sites cover a broad precipitation gradient (770 to 1500 mm a
1) and are underlain by shallow water tables (