Spatio-temporal succession and prediction of carbon storage in ecological conservation area of western Beijing based on InVEST-PLUS model

[Objective] By studying the spatial and temporal succession pattern and development trend of ecosystem carbon storage driven by land use change in the ecological conservation area in the west of Beijing from 1990 to 2020, this study found out the distribution of regional carbon storage and its influencing factors, and combined with the strategic demand of "dual carbon" in Beijing, proposed ways to improve the carbon sink capacity of regional ecosystem. It provides reference for ecological conservation area to support the realization of carbon neutrality goal of the capital. [Methods] Seven periods of remote sensing data from 1990, 1995, 2000, 2005, 2010, 2015 and 2020 were selected to evaluate the temporal and spatial changes of carbon storage in the study area using InVEST model. Based on the historical land use change, the PLUS model was used to predict and analyze the changes of land use and carbon storage potential under different scenarios in 2030. [Results] (1) From 1990 to 2020, the land use types of cultivated land and grassland in the western ecological conservation area of the capital continued to decrease. The cultivated land is especially obvious, which is mainly transformed into construction land and distributed in the west of Fangshan District. (2) Carbon reserves in the ecological conservation area in the west of the capital will reach 105.7×106t in 2020, and forest land will be the main contributor of carbon reserves, which will decrease by 5.3×106t compared with 1990. In terms of space, the high carbon storage area is located in Mentougou District and the west of Fangshan District. The low carbon storage area is distributed in cultivated land and construction land, mainly located in the east of Fangshan District. (3) From 2020 to 2030, the carbon storage of ecological conservation area in the west of the capital increased by 0.38×106t under ecological protection scenario, 0.12×106t under cultivated land protection scenario, and 0.32×106t under natural development scenario. In the context of ecological protection, forest land, cultivated land and grassland constitute the main carbon pool in the study area, and the expansion of construction land is one of the factors that hinder the increase of carbon storage. [Conclusion] In order to improve the carbon sink capacity of the ecological conservation area in the west of the capital, it is necessary to improve the ecological compensation policy, increase the investment in protection, and continue to carry out the construction of landscape engineering and small watershed comprehensive management. In combination with the control of land use, we will strictly curb the disorderly expansion of construction land and optimize and adjust the "three life" space.