Soil storage and plant controls on carbon and water fluxes in seasonally dry ecosystems

Friday, 19 December 2014
Rodolfo Marcondes Silva Souza1, Xue Feng2, Giulia Vico3, Romualdo Lima4, Eduardo Souza5, Antonio Antonino1, Suzana Montenegro1 and Amilcare M Porporato6, (1)UFPE Federal University of Pernambuco, Recife, Brazil, (2)Duke University, Durham, NC, United States, (3)SLU Swedish University of Agricultural Sciences Uppsala, Uppsala, Sweden, (4)Federal Rural University of Pernambuco, Garanhuns, Brazil, (5)Federal Rural University of Pernambuco, Serra Talhada, Brazil, (6)Duke Univ, Durham, NC, United States
The effects of seasonal and interannual rainfall variability on the water and carbon fluxes are investigated along a rainfall gradient with different rainfall amounts and duration of the wet season. To this purpose we use stochastic ecohydrological models and measured data in three different sites in Northeast Brazil, ranging from mesic to semi-arid conditions, to predict productivity of paired ecosystems consisting of pasture and seasonally dry forest.

Hysteretic loops in mean soil moisture, evapotranspiration, carbon fluxes from these ecosystems are also analyzed to understand the different roles of soil water storage and plant phenology in creating asymmetry in the ecosystem response with respect to the seasonal forcing.