Estimating terrestrial ecosystem carbon storage change in the YREB caused by land-use change under SSP-RCPs scenarios

Abstract

Terrestrial ecosystems, as an essential carbon sink of atmospheric CO2, play an important role in balancing the global carbon cycle. Land-use and land-cover changes (LUCCs) are the major factors in terrestrial ecosystem carbon storage (TECS) change. However, they are not yet sure how future LUCCs would affect the TECS in the Yangtze River Economic Belt (YREB) to meet China's carbon-neutral goal. We simulated eight land-use change scenarios and used these to estimate the YREB's TECS and its 2020–2060 variation by coupling the spatially explicit projections of LUCCs under the latest IPCC, combining shared socioeconomic pathways (SSPs) and representative concentration pathways (RCPs) with datasets on terrestrial ecosystem carbon density dataset. Results show that: 1) the total TECS of the YREB in 2020 is ∼28.07 Gt. Spatially, TECS in the YREB focused on Sichuan and Yunnan (∼13.35 Gt), which plays a crucial role in balancing the regional carbon cycle; its losses are in Jiangsu, Zhejiang, and Hunan provinces; Yunnan is the potential region with future carbon sink enhancement in the YREB. 2) Compared to the TECS change under eight land-use scenarios, the low-carbon and sustainable development pathways are the priority chosen by humans. 3) The replacement of vast forest land with cropland and urban expansion are the key factor of TECS change in the YREB. 4) Land management policies (i.e., Cultivated land requisition-compensation balance) should balance the conflicts between food self-sufficiency and the carbon sink rather than only the dynamic balance in quantity. Our study aims to provide data support for the government in planning future development pathways and refining carbon emission reduction strategies to assist in carbon trading and compensation and achieve the YREB's dual-carbon goal.