Climate-Related Changes in the Vegetation Cover of the Taiga and Tundra of West Siberia over the Period of 1982–2015 Based on Satellite Data

Abstract

This paper presents the results of a trend and correlation analysis of the air temperature and the normalized difference vegetation index (NDVI) performed for the warm season in the taiga and tundra zones of West Siberia over the period of 1982–2015. Both in the taiga and tundra zones, a significant increase in NDVI values is observed in certain months of the spring–summer period amid significant (α = 0.05) positive air temperature trends. The air temperature and NDVI trends have been computed for the taiga and tundra zones from April to October over the period of 1982–2015; the irregularity of their spatial distribution in the study area is demonstrated. It is established that the vegetation development during the warm season is significantly determined by its development in the first month of the warm season (May for taiga and June for tundra). In the taiga zone, the NDVI value in May is formed under the influence of April and May temperatures; in the tundra zone, it is formed in June under the influence of June temperatures. However, the input of May temperatures into the formation of the tundra vegetation cover has increased in recent years due to climate warming. Significant correlation coefficients between the NDVI and averaged temperatures in April–May and May–June are typical for most of the study area, except for coastal northern regions in the first case and southwestern regions in the second case.