دانلود رایگان مقاله انگلیسی تاثیر پارامترهای زیست محیطی در توزیع ببر آمور با مدل MAXENT - نشریه الزویر

Abstract

A better understanding of which biological and anthropogenic parameters are strong predictors of suitable habitats for tigers will help address conservation planning in those areas, which is crucial for maintaining connectivity and preventing further population fragmentation. The aim of this study was to develop a spatial model based on a number of environmental and anthropogenic variables as well as tiger presence data from a 2005 large-scale winter survey to predict Amur tiger distribution within its range in the RFE. Modeling the geographic distribution of Amur tigers required an application of the MaxEnt algorithm using a dataset of 1027 tiger track records and a set of environmental variables, such as distance to rivers, elevation and habitat type, and anthropogenic variables, such as distance to forest and main roads, distance to settlements and vegetation cover change. The models were divided into two groups based on elevation and habitat type. Elevation (AUC = 0.821) appeared to be a better predictor of habitat suitability for tigers than habitat type (AUC = 0.784).

Discussion

According to the AUC values, the best predictor of tiger distribution is altitude, rather than type of habitat. Assessment of the relative importance of each of these parameters is best performed on the basis of their ecological relevance to the species. Habitat type is likely to have greater significance in terms of species ecology, as highly productive habitats, such as mixed forests with a predominance of Mongolian oak and Korean pine are key habitats for wild boar — the most preferred prey of the tiger. However, tigers can inhabit a variety of habitats with different arrays of prey species. Differences between the individual types of habitats in this case are not always obvious and easy to interpret. On the other hand, elevation is associated with several parameters that can influence the distribution of the predator, including habitat type. Previous studies (Miquelle et al., 2006) revealed that Amur tigers prefer using river valleys as movement corridors. A seasonal concentration of ungulates occurs in the valleys as well. These results are confirmed in the present study by the fact that distance to the river in all four MaxEnt models was the second major parameter