Influence Of Landscape Dynamics On The Habitat And Corridor Construction Of White-headed Langurs

The white-headed langur(Trachypithecus leucocephalus)is a rare primate endemic to the karst region of Guangxi,and is a Grade 1 priority animal in China.In recent years,habitat fragmentation has become an increasingly serious problem for the white-headed langur,with limited food resources and a patchy or blotchy distribution.Landscape changes caused by urban expansion and agricultural reclamation often exacerbate habitat fragmentation,thereby interfering with the survival and reproduction of the species and reducing the genetic diversity of the entire population.This study therefore examines the impact of landscape dynamics on the habitat of the white-headed langur,using the years2000,2010 and 2020 as the study period,and how to plan an ecological safety network in the context of dynamic change.The main findings of this study are as follows.(1)The results of the analysis of land use change show that the degree and direction of change in land use types vary from one period to another.29% of the land was involved in transformation during the period 2000-2020,with frequent shifts between different land types.Arable land and forest land are the main objects of transfer between each other,indicating the obvious problem of land supply and demand in the area.Measures need to be taken to restructure the land use structure in order to address the contradictions between the Grain for Green Project and the Warning Limit of Arable Land.In addition,the expansion of the town is evident,as in the millennium,the Kaureshan area is still in a natural or semi-natural state,with human impact on the Baekdu leaf climate limited to crop cultivation,while in 2020 the town will have expanded to the edge of its habitat.(2)The results of the landscape pattern change analysis show that the landscape pattern and its changes inside and outside the Baetou langur nature reserve show different characteristics,with patches in the reserve having more complex shape characteristics,more discrete distribution,lower connectivity levels and a highly uneven distribution of various landscape elements.During the period 2000-2020,the landscape connectivity in and around the Long Horn and Daling areas gradually deteriorated,and the degree of landscape fragmentation gradually increased;the rocky hills were 'fragmented' by farmland due to frequent agricultural activities and a large proportion of arable land in the Whiteheaded langur reserve,but the middle and top of the rocky hills still provided habitat and some food sources for the White-headed langur.The central and top of the rocky hills still provide habitat and a partial food source for the langurs.(3)The results of the habitat suitability analysis showed that the factors affecting the habitat suitability of the white-headed langur varied slightly over time,but the main factors were slope > rainfall > land-use > distance to town > Fractional Vegetation Cover.From2000 to 2020,the retention rate of suitable habitat for the white-headed langur was decreasing and the loss rate was increasing;however,in the main activity areas of the white-headed langur,there was still a high retention rate and the average annual habitat loss rate was only 1.03%,so the habitat condition was relatively stable.(4)The results of ecological safety network construction show that the establishment of nature reserves has played a positive role in mitigating the habitat loss of white-headed langurs,and the ecological sources of white-headed langurs are basically located in and around the reserves;the "source-corridor-node" landscape ecological safety pattern was constructed using the minimum cumulative resistance model and the circuit theory model.A total of 53 potential corridors,11 important corridors,52 ecological nodes,and 13 ecological barrier areas were identified.The optimization of ecological safety patterns should strengthen the construction of important corridors and the protection of ecological nodes,and the construction of corridor network should focus on the connection between sources and avoid the formation of ecological islands,and at the same time,different removal plans should be developed for different types of obstacles according to local conditions.