Modelling of Land Use Change and Changes of Pollinator and Natural Enemy Biodiversity in the Huang-Huai-Hai Region under the SSP-RCP Scenarios

To investigate the potential impacts of climate change, economic development, and land use change on pollinator and natural enemy biodiversity in agricultural landscapes, this study integrated the SD-PLUS coupled model with the GLOBIO model to simulate biodiversity changes under different scenarios in the Huang-Huai-Hai region. Land use patterns were projected under two SSP-RCP scenarios—SSP2-4.5 and SSP5-8.5—and the Mean Species Abundance (MSA) index derived from the GLOBIO model was employed as an indicator of pollinator and natural enemy biodiversity. The results show that: (1) Under SSP2-4.5 and SSP5-8.5 scenarios, the forest land and construction land expanded, while the cultivated land, grassland, water body and unused land decreased, and the magnitude of these land use change were more pronounced under SSP5-8.5 scenarios. Specifically, under the two scenarios, the cultivated land decreased by 2.32% and 3.24%, respectively, semi-natural habitats such as forest land and grassland decreased by 1.53% and 1.60%, respectively, and construction land increased by 19.11% and 20.61%, respectively. (2) Under SSP2-4.5 and SSP5-8.5 scenarios, the biodiversity intactness of both pollinator and natural enemy declined across the Huang-Huai-Hai region. The area-weighted mean MSA of pollinator and natural enemy in the study area decreased by 13.03% and 12.50% in the SSP2-4.5 scenario, respectively, while decreased by 15.85% and 15.50% in the SSP5-8.5 scenario, respectively. (3) To protect farmland biodiversity and ecological services related to pollination and pest biological control, we recommend the following strategies for optimizing land-use structure in the Huang-Huai-Hai region, including protect the existing semi-natural habitats in key areas such as the western and northwestern regions of the Taihang Mountains, the southwestern region of the Funiu Mountains, the Taishan Mountains in the east and the hills of Shandong, to mitigate the negative effects of land use change and habitat fragmentation; to enhance the proportion of semi-natural habitats in regions currently lacking such habitats, such as Anhui province, Jiangsu province and eastern Henan Province to increase ecological source areas and ecological corridors.