Spatio-temporal changes of carbon storage, driving factors and their contribution to carbon emission reduction in karst area, southeast Chongqing

Objective The karst area in the southeast of Chongqing is a core region of the karst ecosystem in southwest China and an important ecological barrier in the upper Yangtze River. Conducting research and analysis on the spatio−temporal changes and driving factors of terrestrial ecological carbon storage is of great significance for the ecological environment protection and carbon emission reduction in karst areas. Conducting research and analysis on the spatiotemporal changes and driving factors of terrestrial ecological carbon storage is of great significance for ecological environment protection and carbon reduction in karst areas.

Methods Based on multi−source remote sensing data, GeoSOS−FLUS, InVEST model and geographical detectors to dynamically assess the characteristics of carbon stock changes in the southeast Chongqing karst region from 1990 to 2020, and simulated the spatio−temporal changes of carbon stocks in the southeast Chongqing karst region in 2030 under three different scenarios.

Results ① during the period of 1990−2020, the land use type in the study area is dominated by forest land, which accounts for more than 65% of the total area of the region, and cropland in the study area is the land type with the largest area of land transfer due to the disturbance of anthropogenic activities, and construction land is the land type with the most significant rate of change in the whole. ② In the 30−year time span, the total carbon stock in the study area increased from 26.0051×10⁷ t to 26.7063×10⁷ t, with a growth rate of 2.70%, and the overall trend showed a continuous increase.③Vegetation growth condition, topography, and temperature are the main factors affecting the spatial and temporal changes of carbon stock in the study area, and the carbon stock in the study area in 2030 under the ecological protection scenario is 26.7408×10⁷ t, which is higher than that in the natural growth scenario (26.6816×10⁷ t) and the urban development scenario (26.6041×10⁷ t).

Conclusions From 1990 to 2020, the carbon storage in the karst area of southeastern Chongqing showed an increasing trend, and the driving factors were mainly land use change.Future research should pay more attention to the long−term monitoring and assessment of the impact of land use change on carbon stock, and how to optimize the land use structure through policy intervention, so as to achieve the maximization of regional carbon stock and the sustainable development of the ecosystem.