“…Remote sensing information from the red and near-infrared electromagnetic spectrum is used to calculate the Normalized Difference Vegetation Index (NDVI; Tucker, 1979), which has been widely used to determine drought impacts on forest activity and biomass in several regions worldwide (e.g. Gazol, Ribas, Guti errez, & Camarero, 2017;Lloret, Keeling, & Sala, 2011;Vitali, B€ untgen, & Bauhus, 2017), and only few studies have evaluated forest response to drought across broad environmental gradients, including several biomes, biogeographical regions, and tree species (but see Girardin et al, 2016;S anchez-Salguero, Camarero, Carrer et al, 2017;S anchez-Salguero, Camarero, Guti errez et al, 2017). Although linking tree-ring width and NDVI series may be limited by their different spatial and temporal scales, previous studies suggest a positive relationship between inter-annual NDVI variability and annual radial growth (Coulthard, Touchan, Anchukaitis, Meko, & Sivrikaya, 2017), despite discrepancies between different regions and forest types (Vicente-Serrano et al, 2016).…”