Climate change and anthropogenic activity in the Republic of Buryatia aggravate the processes of
desertification and land degradation. The territory of Buryatia was zoned according to the aridity index based
on ENVIREM climate data with a high spatial resolution. Long-term changes in the vegetation cover in arid
and humid zones are quantitatively assessed based on a combined study of the time series of the normalizeddifference
vegetation index (NDVI) with the Advanced Very High Radiation Radiometer (AVHRR), meteorological
series of the NCEP/NCAR Reanalysis data set, and field studies. Maps of the spatial distribution of
NDVI linear trends and precipitation for 1982–2015 (with the differentiation of the wet (1982–1999) and dry
periods (2000–2015)) have been constructed. During the wet period, positive NDVI trends are observed for
almost the entire republic, while the dry period is characterized by a significant increase in negative trends of
the vegetation index. A positive correlation between the Selyaninov hydrothermal coefficient and NDVI is
observed for intermountain steppe basins, while it is negative for forest landscapes. The dynamics of the
NDVI for steppe vegetation is more dependent on precipitation, while the dynamics of the NDVI for forests
is more significantly correlated with temperature. Reforestation, postpyrogenic succession, the bushing of
fallow lands, and other factors determine the growth in the NDVI. Negative NDVI trends are characteristic
of steppe ecosystems with low precipitation and forest ecosystems exposed to felling and fires.