Abstract:
Background The carbon cycle and greenhouse effect of terrestrial ecosystem have always been the focus of global change research in geoscience, ecology and environmental sciences. Land use change may reflect human land use patterns in an area and plays an important role in spatial soil and water conservation. Regional land use change is the main reason for the change in ecosystem carbon storage, which affects the carbon source and carbon sink effect.
Methods This paper took Puding county in central Guizhou as the research area, based on the carbon storage and sequestration module of InVEST model and ArcGIS technology, combined with land use data and carbon density data, the carbon storage and its spatial pattern in Puding county of central Guizhou province from 1973 to 2020 were estimated and analyzed. Based on the land use type carbon storage transfer matrix, the influence of land use changes on the spatial and temporal distribution of carbon storage was explored.
Results 1) The carbon storage of terrestrial ecosystem in Puding county in 1973, 1989, 2003, 2010 and 2020 were 15.868×106 t, 14.196×106 t, 15.022×106 t, 15.834×106 t and 16.529×106 t, respectively, and the carbon storages of ecosystems decreased first and then increased, with an overall trend of increase and a cumulative increase of 661 000 t, indicating that the ecological restoration project in Puding county has achieved remarkable results and the ecosystem service functions had been significantly improved. 2)The spatial distribution showed a significant increase in the northeast and southwest of Puding county, and a significant decrease in the south-central Puding county. The northeast and southwest of the Puding county maintained a stable trend of increasing carbon storage year by year from 1989 to 2020, while the carbon loss in the middle-south of Puding county was significant from 2010 to 2020, and the highest value areas of carbon storage were distributed in the southwest and northeast of Puding county. 3) Dry land, grassland, paddy field and other woodland were converted into shrubland. Dry land, grassland and other woodland into forest land, and the conversion of dry land to paddy field were the main reasons for the increase of carbon storage in the ecosystem of Puding county and sustainable ecological development, indicating that the increase of shrubland, forest land and paddy field in Puding county is beneficial to carbon sink.
Conclusions The overall carbon reserves of the ecosystem in Puding county have increased, showing the increasing carbon sequestration capacity in the northeast and southwest of Puding county and the decreasing carbon sequestration capacity in the central and southern region of Puding county. In the future, the carbon storage capacity in the south-central Puding county should be emphasized to improve the regional ecosystem quality and soil and water conservation function.