Global correlation analysis for NDVI and climatic variables and NDVI trends: 1982-1990

The relationship between the Normalized Difference Vegetation Index (NDVI) and climatic variables was analysed on a global scale using the Pathfinder AVHRR Land NDVI data set, and observed climate data for the period 1982-1990. A significant correlation between interannual NDVI and temperature variation was recognized in the northern mid- to high latitude areas between spring and autumn. A significant correlation was also identified between the NDVI, temperature and precipitation in northern and southern semiarid regions. A comparison of global NDVI trends show that NDVI increases in the northern mid- and high latitudinal zones are related to temperature rise, and NDVI decreases in southern semiarid regions are due to a precipitation decrease in the survey period. Although the cause of NDVI increases in the equatorial regions remains unclear, the combined effects of forest regrowth, deforestation and fertilization may impact on the NDVI trend.