Spatial and temporal evolution of carbon stocks in Dongting Lake wetlands based on remote sensing data

Abstract

Wetlands are one of the important carbon reservoirs on earth, assessing the spatial and temporal dynamics of wetland carbon stocks and their driving mechanisms is critical for stabilizing and enhancing the carbon sink function of wetlands. In this study, the carbon stocks of Dongting Lake wetland during 1995–2020 were estimated using the Integrate Valuation of Ecosystem Services and Tradeoffs Tool (InVEST) model and land use/cover data derived from remote sensing data. Subsequently, the geographically weighted regression (GWR) model was utilized to explore the driving mechanisms of the spatial and temporal dynamics of carbon stocks based on natural and socio-economic factors. Finally, evolution of land use status and carbon stocks was simulated based on patch-generating land use simulation (PLUS) model during 2030–2050 under different scenarios. The results showed that: 1) over the past 25 years, carbon stocks have been fluctuating in a ‘decrease–increase–decrease’ pattern, with an average decrease of 39.70 × 106 t per year; 2) compared with socio-economic factors, climate conditions have a greater influence on the change of carbon stocks distribution; 3) under the natural variation scenario, the carbon stocks in 2030 is 1345.36 × 106 t, which is increased compared with the year of 2020. However, the carbon stocks in 2040–2050 started to show a decreasing trend. Under the ecological conservation scenario, the increase in forest area leads to a significant increase in carbon stocks from 2030 to 2050, which showed a continuous growth trend and obviously enhanced the carbon sequestration capacity of the Ecological and Economic Circle around Dongting Lake. The results of this study are expected to provide a scientific basis for carbon balance, land use restructuring and wetland resource management planning in the ecological and economic circle around Dongting Lake. Highlights The carbon stocks of Dongting Lake wetland during 1995–2020 were estimated using the InVEST model. Over the past 25 years, carbon stocks of Dongting Lake wetlands have been fluctuating in a ‘decrease–increase–decrease’ pattern. Climate conditions have a greater influence on the change of carbon stocks distribution compared with socio-economic factors.