Habitat Fragmentation Assessment of Castor fiber birulai in the Middle and Lower Reaches of Ulungur River
Based on the field survey conducted on the habitat of Castor fiber birulai in the middle and lower reaches of the Ulungur River basin in Xinjiang,this study utilized landscape pattern indices,landscape connectivity,and the MaxEnt model to examine the current status of habitat fragmentation.This research aims to provide references for the conservation and management of this species and its habitat.The results indicate there are significant changes in the landscape pattern of the studied area from 2000-2020,primarily characterized by the increased areas of cultivated land,built-up areas,and bare land patches,and decreased areas of grassland,forest,and wetland patch.The suitable habitat area for C.f.birulai is narrowly distributed,accounting for only 12%(386.92 km2)of the total area.The primary environmental variables influ-encing the distribution of the suitable habitat for C.f birulai are the minimum temperature of the coldest month(-26.43--23.07℃),the mean temperature of the warmest season(20.31-21.78℃),the precipitation of the driest season(20.04-25.72 mm),the soil pH(7.72-8.01),the soil organic carbon content(1.2%-2.6%),and land use types with distribu-tions of grassland,forest,and water bodies.The landscape connectivity of suitable habitat for C.f.birulai at different dis-persal distances is generally low.It is recommended to establish habitat corridors,increase the connectivity between patches,and improve the habitat for C.f birulai in the middle and lower reaches of the Ulungur River basin.