Abstract:

Vegetation net primary productivity （NPP） is an important index to evaluate vegetation production capacity and carbon sink potential. However， there is a lack of research on NPP in different dry and wet partitions of the same geographical unit. Based on the NPP data， meteorological data， aridity index and vegetation type data provided by MOD17A3HGF data set， this study used trend analysis and partial derivative analysis to explore the spatial and temporal variation characteristics of vegetation NPP in Horqin Sandy Land from 2001 to 2020， and quantified the contribution of climate factors and human activities to NPP changes. The study found that ： （1） The variation characteristics of NPP in Horqin Sandy Land have obvious spatial heterogeneity， showing a distribution pattern that gradually increases from the middle to the east and west， with an average value of 255.29 g·m^-2；（2） From 2001 to 2020， the NPP of 97.15% of Horqin Sandy Land showed a very significant upward trend （P<0.001）， with an average annual increase of 4.06 g·m^-2； （3） The driving factors of vegetation NPP recovery in different aridity areas of Horqin Sandy Land are different. The semi-arid area is affected by climate factors and human activities. The semi-humid area is dominated by climate， and the humid area is dominated by human activities. This study better explains the contribution rate of different driving factors to the change of NPP under multiple dryness partitions， which has theoretical significance and practical guiding value for optimizing the industrial structure of Horqin Sandy Land and promoting ecological protection and restoration projects in China.

Key words: net primary productivity, driving factors, climatic factor, human activities, Horqin Sandy Land