“…The longest continuous record of NDVI data comes from the Advanced Very High Resolution Radiometer (AVHRR) instrument onboard the NOAA satellite series 7, 9, 11, 14, 16, and 17, starting in July 1981 (Pettorelli et al, ). Recent studies in diverse regions of the world in which the GIMMS NDVI time series data from the AVHRR instrument has been used to detect changes in photosynthetically active vegetation reveal diverse patterns of decline and increase in vegetation productivity (Erasmi, Schucknecht, Barbosa, & Matschullat, ; Huang & Kong, ; Ibrahim, Balzter, Kaduk, & Tucker, ; Vu, Le, & Vlek, ). In these studies, various methods were used to aggregate the NDVI data, including annual mean NDVI (Ibrahim et al, ; Vu et al, ), annual sum of NDVI (Erasmi et al, ), and seasonal sums of NDVI (Huang & Kong, ).…”