青海省都兰县棕熊适宜栖息地与日活动节律OA北大核心CSTPCD

Ursus arctos pruinosus is a unique subspecies of brown bear found in the Qinghai-Tibet Plateau,which serves as an umbrella and flagship species for biodiversity conservation.To manage and protect this species,it is very impor-tant to understand the factors that determine its suitable habitat distribution,as well as its daily activity patterns.From July 2021 to July 2022,a monitoring program was conducted in Dulan County,Qinghai Province,using 150 infrared camera traps to survey the Ursus arctos pruinosus.The MaxEnt model was used to predict its historical and future habi-tat distributions by combining three topographic variables(elevation,slope,and aspect)as well as 19 bioclimatic vari-ables using data from the base period of 1970-2000 and the future climate of 2040-2060 projected by the Coupled Model Intercomparison Project Phase 6(CMIP6)under the medium development path.Based on the data captured by the infrared cameras,the daily activity patterns of Ursus arctos pruinosus were estimated using kernel density estima-tion.The results showed that the MaxEnt model has a high predictive accuracy for the suitable habitat distribution of Ur-sus arctos pruinosus in both the historical and projected future time periods,with the area under the receiver operating characteristic curve exceeding 0.9,indicating reliable predictions.The main environmental factors affecting the habitat distribution of Ursus arctos pruinosus were elevation,minimum temperature of coldest month,and annual temperature range.Under projected future climate conditions,there will be a slight increase in the unsuitable habitat area for Ursus arctos pruinosus and the highly suitable habitat in Gouli Township will shift eastward.We found that the daily activity of Ursus arctos pruinosus mainly occurs at night following a crepuscular pattern,with peak activity occurring around sunset.This study identified the spatial distribution of Ursus arctos pruinosus in Dulan County and the factors influenc-ing it,and then predicted future trends in this distribution.Given the unique daily activity patterns of Ursus arctos pru-inosus compared to other brown bear subspecies,we believe that the region may face more severe human-bear conflict in the future and should be given more attention in conservation work.