The Influence Of Landscape Heterogeneity On Multi-Scale Species Diversity-Distinguish The Effects Of Environment And Human Activity

The influence of landscape heterogeneity on biodiversity has become a research focus. This study obtained the data of the landscape heterogeneity and environment through automatic information extraction. These data involve the 1270 species quadrats in the 53 survey areas in Tabu River Basin which is located at the agro-pastoral ecotone of Inner Mongolia, China. According to these data, landscape heterogeneity is classfied into landscape heterogeneity of environment (LH-environment) and landscape heterogeneity induced by huaman activity (LH-human). Moreover, biodiversity can be divided into three levels:species richness within patches (S-patches), species richness between patches (S-b-patches) and landscape scale species richness (S-landscape). In addition, this research explored the composition of S-landscape and the responses of three different levels of biodiversity to landscape heterogeneity in the agro-pastoral ecotone of Inner Mongolia. Meanwhile, this study also analyzed the effects of LH-environment, LH-human and environmental variables on the maintenance of S-landscape in this areas based on a structural equation model.The results indicate as follows:(1) This study provides a method of automatic information extraction for land use in agro-pastoral ecotone with an overall accuracy of 88.40%. (2) The S-patches is shown to be an dominant compositions in S-landscape of Tabu River. With the increase of S-landscape, the proportion of S-patches decreases, while the proportion of S-b-patches has shown a gradual increase. (3) S-landscape raises with the increase of LH-environment and LH-human, and S-patches increases with the growing LH-environment. In addition, S-b-patches tends to rise with the increase of LH-human. (4) LH-environment is the main reason explaning the survival of S-patches and the heterogeneity of annual average precipitation has a greatest contribution; while LH-human mainly contributes to the survival of S-b-patches. (5) S-b-patches is a key factor influencing the changes of S-landscape and exhibits an negative effect in some areas. Therefore, it is suggested to reasonably control the intensity of human activities so as to prevent species diversity from being reduced.