The Sensitivity and Response of Terrestrial South American Vegetation to Interannual Climatic Variability Induced by the ENSO

Abstract

The sensitivity of vegetation to climatic variations operates over a range of spatio-temporal scales. Whilst comprehensive and extensive studies that involve the spatial changes in terrestrial systems using remotely sensed data have been undertaken, only a few investigations have focused on temporal change in these systems. In this study econometric time-series modelling techniques were applied to National Oceanographic and Atmospheric Administration Advanced Very High Resolution Radiometer Normalized Difference Vegetation Index data sets in order to evaluate the resistance and resilience of terrestrial South American vegetation to the interannual El Nino Southern Oscillation perturbations. Lags between vegetation response and the El Nino Southern Oscillation perturbations are identified and quantified. The results indicate that the terrestrial vegetation loses its sensitivity to El Nino Southern Oscillation perturbations in the post 1993 period. This hypothesis is investigated further using stochastic Auto Regressive Integrative Moving Average model simulation techniques.