The regional spatial and inter-annual response of the Enhanced Vegetation Index (EVI, as a proxy for
aboveground net primary production) to environmental controls was evaluated in drylands of SE Spain.
By means of linear mixed-effects models we found that both the spatial patterns and inter-annual trends
of the EVI annual mean were explained by climate variability but clearly modulated by lithology and
vegetation. Along the spatial gradient, precipitation increased the EVI mean even compensating for the
greater evapotranspiration of warmer sites. Limestones, with high available water content, showed the
lowest dependence of EVI mean on precipitation. The greater capacity of scrublands to store and use soil
moisture was only evident on marls sites. The observed 2001e2010 trends toward less stressful conditions
(precipitation rises and temperature declines) led to EVI mean increases. This EVI mean response
was steeper in grasslands, with shallow roots, and marls, with low available water content. The study
revealed the importance of analyzing the seasonal timing of trends in Mediterranean drylands, where
temperature and precipitation are out of phase. The observed earlier rain-arrival after summer drought
and cooler early-autumn, caused very strong EVI increases at the beginning of the growing season that
may favor the rest of the season.