Spatiotemporal pattern and multi-scenario prediction of carbon sequestration capacity in the Changsha-Zhuzhou-Xiangtan Green Heart Area.

Abstract

As an important ecological barrier, the Changsha-Zhuzhou-Xiangtan Green Heart Area is responsible for providing public ecological services for urban development. We used the FLUS-InVEST model to analyze the spatiotemporal patterns of land use, carbon storage, and carbon sink capacity in the Changsha-Zhuzhou-Xiangtan Green Heart Area from 2010 to 2020 based on multi-source data, and predicted carbon storage and carbon sequestration under different scenarios in 2030 and 2060. The results showed that land use pattern in the Green Heart Area had undergone significant changes during the study period. From 2010 to 2015, the area of forest, cultivated land, and grassland displayed a decrease, while the area of construction land, wetland, and water expanded. The land types with the largest decrease and increase in area were forest (loss of 36.25 km²) and construction land (increase of 53.05 km²), respectively. During 2015-2020, the land use decreased significantly in the following order: construction land (5.94 km²), grassland (6.53 km²), and wetland (4.62 km²). The land use increased significantly in the following order: cultivated land (12.94 km²), forest (3.07 km²), and water (1.08 km²). Both cultivated land and forest were at a net inflow state during this period. The carbon source areas in the Green Heart Area showed a downtrend from 2010 to 2020, decreasing from 259.44 km² in 2010-2015 to 233.32 km² in 2015-2020. The carbon balance and sink areas represented an increasing trend, increasing from 185.71 and 76.06 km² in 2010-2015 to 204.56 and 89.79 km² in 2015-2020, respectively. The overall carbon sequestration capacity exhibited a spatial pattern of firm in the east and west, weak in the central region, which was closely related to the changes in carbon storage in the Green Heart Area. In 2030 and 2060, the carbon storage and sink capacity of the Green Heart Area demonstrated an increasing trend under the S1 scenario (natural development), S2 scenario (farmland protection), and S3 scenario (ecological protection), indicating that ecological protection was the optimal development scenario. The carbon balance area was the most widely distributed in the three scenarios, with the carbon sink area mainly distributed in the eastern part of the Green Heart Area and along the Xiangjiang River and the carbon source area concentrated in the construction land east of the Xiangjiang River. Controlling construction land and strictly enforcing ecological protection regulations was a key pathway to enhance carbon sequestration capacity of the Green Heart Area.