Abstract:
【Objectives】 To explore the change characteristics and influencing factors of vegetation total primary productivity in Qilian Mountain National Park from 2001 to 2020 and to provide theoretical basis and data support for ecological restoration and sustainable development in this area. 【Methods】 Based on gross primary productivity (GPP) data from MOD17A3, combined with meteorological, land use, and other data of the same period, methods such as trend analysis, Hurst index, and partial correlation analysis were applied to analyze the spatiotemporal variation characteristics of GPP of different vegetation types and their responses to environmental factors in Qilian Mountain National Park from 2001 to 2020. 【Results】 1) From 2001 to 2020, the vegetation GPP in Qilian Mountain National Park showed a decreasing trend from southeast to northwest in space, and the area with GPP between 200 and 400 gC/(m
2·a) accounted for the largest proportion (25.35%), and 99.0% of the area showed an increasing trend. 2) From 2001 to 2014 and from 2015 to 2020, the GPP in this area showed an increasing trend, and the growth rate of different vegetation types was forests > shrubs > grasslands, and the growth rate from 2015 to 2020 was greater than that from 2001 to 2014. 3) In Qilian Mountain National Park, 65.37% of the area had a future change trend of increasing to decreasing, and the change characteristics of the same direction were higher than those of the opposite direction. 4) The relationship between GPP and temperature and precipitation in Qilian Mountain National Park showed some spatial heterogeneity, and it had a linear relationship with elevation. For every 1m increase in elevation, GPP decreased by 0.51 gC/(m
2·a). 【Conclusions】 In the past 20 years, the vegetation restoration of Qilian Mountains has been developing steadily, and the establishment of national parks has played a great role in the local ecological restoration.