Habitat suitability evaluation of Microcos paniculata L. in China based on MaxEnt model

【Objective】This study aimed to elucidate spatiotemporal revolution characteristics and climate adaptability of habitats of Microcos paniculata L. in China using MaxEnt model and GIS spatial analysis to clarify the driving mechanism of key climate factors on Microcos paniculata L. distribution， thereby providing scientific basis for establishing conservation regions of germplasm resources of southern Chinese medicinal plants and site selecting for artificial cultivation base.【Method】Based on 237 distribution sites and 38 environmental factors， the combined application of MaxEnt model and GIS spatial analysis， along with contribution rate analysis and jackknife test， were employed to evaluate the effects of environmental factors on habitats of Microcos paniculata L. in China. Based on spatial analysis using the SDM-Tools module， the habitat revolution of Microcos paniculata L. from the last glacial maximum （LGM） to current， and the future distribution patterns under the low concentration greenhouse gas emission scenario （SSP126） and high concentration greenhouse gas emission scenario （SSP585） were predicted for further evaluating the conservation status.【Result】The key environmental factors affecting habitats of Microcos paniculata L. in China were identified as annual mean temperature （Bio1）， precipitation of driest quarter （Bio17）， mean temperature of wettest quarter （Bio8）， and precipitation of wettest quarter （Bio16）， among which the temperature factor showed a cumulative contribution rate of 68.2%， and the precipitation factor exhibited an obvious synergistic regulatory effect. Under the current climate conditions， the total potential habitat area reached 36.03×10⁴ km²， with its core region concentrating in the Lingnan region. From the LGM to the current， habitats of Microcos paniculata L. in China exhibited a distribution pattern of contraction toward tropical climate zones， with the centroid shifting 206.19 km southeast. Under the future SSP126 scenario， the centroid of habitats of Microcos paniculata L. in China shifted northwest， as the pathway was southeast → northwest → northwest → northwest； under the future SSP585 scenario， the centroid of habitats of Microcos paniculata L. in China shifted northeast， as the pathway was northwest → southwest → northeast → southeast.【Conclusion】Under the current climate conditions， habitats of Microcos paniculata L. in China are distributed mainly in the Lingnan region， and the distribution pattern is related to hydrothermal conditions， among which the temperature factor and precipitation characteristics jointly drive the spatial distribution pattern of Microcos paniculata L. Under the future climate conditions， potential habitats of Microcos paniculata L. show a decline in expansion rate and even negative growth in a later period， with a tendency to shift northwest.Therefore， priority should be given to strengthening the protection and management of the core distribution area in the Lingnan region， while ecological corridors should be constructed in the northwestern migration zone to address habitat shifts induced by climate change.