Abstract: Aims Nei Mongol is an important ecological security barrier in northern China, and the study of changes in its vegetation productivity is of great significance to the ecological security of the northern region. Methods Based on multi-source remote sensing data such as Eddy Covariance-Light Use Efficiency Gross Pri-mary Productivity (EC-LUE GPP) in Nei Mongol from 1982 to 2017, this paper uses trend analysis and correlation analysis to analyze the temporal and spatial variation characteristics of vegetation gross primary production (GPP) in Nei Mongol and its correlation with air temperature, precipitation and soil moisture. On this basis, multiple linear regression and residual analysis methods were used to decompose and quantify GPP under the influence of climate changes and human activities, divide different time periods to carry out its impact on vegetation GPP, and explore the impact of different vegetation types on the driving factors response. Important findings (1)Three meteorological elements showed good correlation with vegetation GPP, among which precipitation and soil moisture had higher correlations with GPP. (2)During the period 1982-1990, vegeta-tion GPP showed an insignificant fluctuation and increased, with an average annual increase of 1.8333 g C·m–2·a–1, and the remaining three time periods (1991-2000、2001-2010、2011-2017) showed an insignificant downward trend, with annual average decreases of 1.2967 g C·m–2·a–1、-0.2356 g C·m–2·a–1、3.6589 g C·m–2·a– 1. The areas with an overall downward trend accounted for 55% of the total area, and the other 45% showed a significant upward trend; (3)Except for the period from 2001 to 2010, climate changes played a decisive role in vegetation restoration in the other three time periods (1982-1990, 1991-2000, and 2011-2017), explaining 20%, 16% and 13% of veg-etation restoration, respectively; Human activities dominated vegetation degradation areas, with 13%, 19% and 20% explaining vegetation degradation, respectively. The research results can provide scientific reference for the implementation of ecological environmental protection and management policies and green and sustainable de-velopment in Nei Mongol.

Key words: climate changes, human activities, gross primary productivity, residual analysis, Nei Mongol