Macroeconomics

Central asia

Climatology

Ecology

Biology

Growing season

Normalized Difference Vegetation Index

Precipitation

Economics

Vegetation (pathology)

Physical geography

Geology

Primary production

Arid

Climate change

Geography

Productivity

Environmental science

Vegetation Index

Enhanced vegetation index

Medicine

Tropical vegetation

Meteorology

Phenology

Tropics

Ecosystem

Pathology

The Science of The Total Environment

Vegetation is highly sensitive to climate changes in arid regions. The relationship between vegetation and climate changes can be effectively characterized by vegetation phenology. However, few studies have examined the vegetation phenology and productivity changes in arid Central Asia (ACA). The vegetation phenological information of ACA was extracted using MODIS NDVI (Normalized Difference Vegetation Index) data, and the dynamics of vegetation phenological changes under spatiotemporal variations were quantitatively assessed. Moreover, the impacts of climate change on vegetation phenology and net primary productivity were analyzed by combining meteorological data with that of MODIS NPP (Net Primary Productivity) during the same period. The results demonstrated that the start of the season (SOS) of vegetation in the study was concentrated from mid-February to mid-April, while the end of the season (EOS) was concentrated from early October to mid-December. The length of growing season (LOS) ranged from 6 to 10 months. The SOS of vegetation was gradually postponed at a rate of 0.16 d·year−1. The EOS advanced at a rate of 0.69 d·year−1. The LOS was gradually shortened at a rate of 0.89 d·year−1. For each per 1000 m increase in elevation, the SOS of vegetation was postponed by 12.40 d; the EOS advanced by 0.40 d, and the LOS was shortened by 11.70 d. For the impacts of climate changes on vegetation phenology and NPP, the SOS of vegetation phenology negatively correlated with temperature but positively correlated with precipitation and NPP. The EOS and LOS positively correlated with temperature but negatively with precipitation and NPP. Results indicated that the SOS was not moved ahead but was delayed, while the EOS advanced rather than being postponed under climate change. These results can offer new insights on the phenological response to climate change in arid regions and on non-systematic changes in phenology under global warming.

Impacts of climate change on vegetation phenology and net primary productivity in arid Central Asia