Habitat Suitability Assessment Of Rhinolophus Based On Multisource Data In Wuling Mountain Area

At present,the global species diversity is facing a huge threat.The destruction and the loss of species habitat will lead to the extinction of species.The study of species habitat selection mechanisms and the prediction of the spatial distribution of species have important guiding significance for the conservation of endangered species.Wuling Mountain area is one of the most important distribution areas for Rhinolophus.In this paper,Wuling Mountain area is taken as the study area.Using field investigation data,Landsat8 OLI data,meteorological data,DEM data and land use data,supported by the software of Arc GIS,ENVI and SPSS,carried out the screening of habitat factors through normality analysis,correlation analysis and difference analysis.The mechanism model,binary logistic regression model and maximum entropy model(MAXENT)were used to analyze the habitat suitability of Rhinolophus in Wuling Mountain area.The indicators such as AUC calculated by ROC curve were used to verify the model,and the optimal model is obtained.Based on the optimal model,the dominant factors affecting the habitat selection of the Rhinolophus were determined.The results obtained are as follow:(1)The mechanism model analysis showed that without considering the influence of human disturbance,the available habitat reached 54.62%,mainly distributed in the central,eastern and southern parts of Wuling Mountain area;the non-available habitats accounted for 45.38%,mainly distributed in the western and northern regions.However,when considering the human disturbance factors,the unsuitable habitat area increased to69.27%.The increased area was mainly distributed near roads and residential land,indicating that human disturbance had great influence on habitat suitability of Rhinolophus.Through the evaluation of mechanism model,the results showed that the model's overall prediction accuracy was 55.17%,indicating that the model has low accuracy.(2)In this paper,the habitat factors used to construct the logistic habitat suitability model of Rhinolophus were screened by correlation analysis and difference analysis.The results showed that the main factors affecting the habitat selection of Rhinolophus was the nearest distance from the roads,residential land and rivers,slope and the average annual temperature.Through the evaluation of Logistic model,the results showed that the model's overall prediction accuracy was 72.73%,the model's corresponding AUC value was 0.947,and the AUC value changed with the change of sample size,indicating that the model has high accuracy,but it is greatly influenced by sample size.Finally,the dominant factors were input into the model and the grid calculations were performed to obtain the spatial distribution of the habitat suitability of the Rhinolophus.According to statistical analysis,the available habitat area is 83408.65km~2,accounting for 48.51%of the study area,and is mainly distributed in the central and northern parts of Wuling mountain area;the non-available habitat area is 88534.9km~2,accounting for 51.49%of the study area,and is mainly distributed in the south area.(3)The habitat suitability evaluation model of MAXENT was established by using the survey data and ecological environment data of the Rhinolophus.Firstly,the importance of each ecological factors was analyzed by using Jackknife method.The main factors affecting the habitat suitability of the Rhinolophus were the annual average temperature,annual precipitation,the nearest distance to the residential land,and the vegetation coverage.Through verifying the model,the results showed that the model's overall prediction accuracy was 96.55%,the AUC values of the test data and verification data were 0.984 and 0.973,respectively,and the AUC value remained relatively stable with the change of the sample size.It indicated that the model had higher precision and was less influenced by the sample size.So it is the preferred method for evaluating the habitat suitability of Rhinolophus.Finally,the spatial distribution prediction of the habitat suitability of the Rhinolophus in Wuling Mountain was conducted using the model.The results showed that the unsuitable habitat area was127233.33km~2,accounting for 74%of the total area of Wuling mountain area;the less suitable habitat area was 25141.28 km~2,accounting for 14.62%of the study area,marginally suitable habitat area was 13373.08 km~2,accounting for 7.78%of the Wuling Mountain area,suitable habitat area was 6195.86 km~2,accounting for 3.6%of the study area.The distribution of Rhinolophus was mainly concentrated in the middle part of Wuling mountain.Marginally suitable habitats and less suitable habitats were mainly concentrated on the edge of suitable habitat.The unsuitable habitat was distributed in the southern and northwestern areas of Wuling mountain area.(4)The results of model screening were used to determine the importance of each habitat factor.The results showed the dominant factors of habitat suitability were identified as annual mean temperature,annual precipitation,nearest distance to residential land and vegetation coverage.Firstly,we can conclude that the annual mean temperature which is between 12.6?and 13.5?is the most suitable temperature to survival.Secondly,the habitat distribution probability of Rhinolophus gradually increases with the increase of annual precipitation.When the precipitation is more than1400mm,the habitat distribution probability of Rhinolophus does not change any more,indicating that Rhinolophus like activity in the area with high humidity.For the disturbance factor,when the nearest distance to residential land is less than 2.5km,the habitat distribution probability of Rhinolophus increases with the increase of the distance from residential land,revealing the disturbance effect of residential land,and then habitat distribution probability decreases gradually,the disturbance of residential land is no longer significant.At the same time,the results of the model also showed that the roads,rivers and farmland have certain influence on the habitat selection of Rhinolophus.Vegetation coverage between 50%and 86%is most suitable for the survival and activity of Rhinolophus.In this study,What's more,the terrain factor is not an important factor,but it also has an impact on the habitat suitability of Rhinolophus.Elevation and slope can affect the formation of caves;aspect can affect the light intensity,so the terrain has a certain influence on the habitat suitability of the Rhinolophus.