Spatiotemporal Variation and Dynamic Simulation of Ecosystem Carbon Storage in the Loess Plateau Based on PLUS and InVEST Models

Abstract

Terrestrial ecosystems play an important role in carbon reduction and sequestration, and it is important to explore the carbon sequestration potential of terrestrial ecosystems under different land use scenarios to enhance the regional carbon storage potential. We analysed land use changes in the Loess Plateau, an important ecological barrier in China, from 2000 to 2020, used the PLUS model to predict land use patterns under different scenarios in 2035, and applied the InVEST model to assess carbon storage from 2000 to 2035. The findings were as follows: (1) Cropland in the study area decreased significantly from 2000 to 2020, and forests, waters, and construction land showed an increasing trend. The area of cropland further decreased under the natural growth and ecological protection scenarios, the area of grassland decreased significantly under the cropland protection scenario, and forests and waters were effectively protected under the natural development, ecological protection, and cropland protection scenarios. (2) Carbon storage in the Loess Plateau has increased by 28 Tg (0.56%) over the past 20 years. Compared with those in 2020, by 2035, carbon storage under the natural development, ecological protection, and cropland protection scenarios will increase by 30, 44, and 21 Tg, respectively. (3) Carbon storage has obvious spatial heterogeneity, with high carbon density in the northern Qinling Mountains, Taihang Mountains, and Lvliang Mountains and low carbon density in Erdos City and its surrounding areas. Regional differences in carbon density are closely related to the spatial distribution of land use types. (4) Carbon storage showed an inverted V-shaped trend with the increase in elevation. Land use change is the main reason for the increase or decrease in carbon storage under different scenarios. Compared with the other two scenarios, the ecological protection scenario not only protects the ecological environment but also has a strong carbon storage potential, which may be significant for guiding the formulation of future land use planning on the Loess Plateau.