Assessment Of Habitat Suitability And Corridor Planning For Sichuan Snub-Nosed Monkeys In Shennongjia

Sichuan Golden Monkey(Rhinopithecus roxellanae)is an endangered species unique to China,and the Shennongjia area is the easternmost natural distribution of this population.The population in this area has an isolated genetic status and smaller population size,which makes it more vulnerable to human disturbance and climate change.To effectively protect the Sichuan Golden Monkey in the Shennongjia area and develop conservation strategies,it is necessary to clarify their suitable habitat range and the main environmental factors affecting their distribution.This study used MaxEnt model based on indices such as the distribution points of the Sichuan Golden Monkey,bioclimatic factors,geographic environmental variables,terrain undulation,and landscape disturbance degree represented by landscape disturbance,among others.The 2013 data was projected to 2021,and the suitable habitats of the Sichuan Golden Monkey in 2013 and 2021 were predicted.The Morphological Spatial Pattern Analysis(MSPA)was used to identify the core area of suitable habitat,and Conefor software was used to calculate the importance of different patches in the core area at a distance threshold,to determine the core patches.The suitability index of the habitat obtained by the MaxEnt model was transformed into an ecological resistance surface,and the ecological corridor between the core source areas was identified via the linkage mapper.The primary results are as follows:(1)Climate factors are the most important factor affecting the distribution of the Sichuan Golden Monkey in Shennongjia,with an importance of 52.66%.Among them,the most important is the average annual temperature(bio＿1)with a suitable range of4-10 ° C,followed by precipitation seasonality(bio＿15)with a suitable range of61-64 mm.Altitude and distance from rivers are the two variables with the highest importance,except for climate factors.(2)Among the two newly added variables,the importance of the landscape disturbance degree is only 2.45%,and its impact on the distribution of the Sichuan Golden Monkey is relatively small.The monkeys tend to choose areas with low landscape disturbance degree,and as the landscape disturbance increases,the suitability of the habitat gradually decreases.The importance of terrain undulation is4.87%,and as the terrain undulation increases,the suitability of the habitat gradually decreases.(3)The suitable habitat area for the Sichuan Golden Monkey in 2013 was196.67km2,and the sub-suitable habitat area was 331.82 km2.By 2021,the suitable habitat area increased by 3.35 km2,and the sub-suitable habitat area decreased by5.81 km2.The suitable habitat area accounted for approximately 6% of the total area of Shennongjia.(4)The MSPA identified the core area of suitable habitat in 2013 and 2021,and the core area increased by 1.16 km2 in eight years.The overall connectivity of the core area of suitable habitat in 2021 was lower than in 2013,and the center of the core area moved eastward.(5)The ecological corridor was distributed only in the western area of Shennongjia.Thirteen corridors connected nine core patches in the western area of Shennongjia,and five corridors had high importance.(6)In 2021,there was a protection gap in 32.31% of the suitable habitat for the Sichuan Golden Monkey in Shennongjia,with an area of 64.63 km2.This protection gap was mainly located in the northeast of the Shennongjia Nature Reserve.In conclusion,this study revealed the main environmental factors affecting the distribution of the Sichuan Golden Monkey and clarified the impacts of landscape disturbance and terrain undulation on their distribution.It analyzed the changes in the landscape structure of the suitable habitat of the monkeys,identified protection gaps,and constructed ecological corridors,which provide a reference for the habitat protection and management of the Sichuan Golden Monkey in the Shennongjia area.