Research Progress on Assessing the Impacts of Urban Expansion on Natural Habitats

Urban expansion has become one of the main factors influencing natural habitats. Understanding the advances on the assessments of the impacts of urban expansion on natural habitats is of great significance to balance the contradiction between urban expansion and natural habitats protection and to improve urban sustainability. Therefore, this paper reviewed the assessments of the impacts of urban expansion on natural habitats. The results showed that the number of papers and the frequency of citations continuously increased. Previous studies mainly evaluated the impacts of urban expansion on natural habitats in broad sense, and emphasized the impacts on the area and spatial patterns of natural habitats. The scale of previous studies concentrated on the local scale, and the spatial statistics were used as the most popular assessment method. Previous studies have laid a good foundation for understanding the impacts of urban expansion on natural habitats, but there are shortcomings in several aspects of contents, scales and methods. To solve those shortcomings, we propose a framework for assessing the impacts of urban expansion on natural habitats based on the principle of "multiple perspectives, multiple scales, and multiple methods". This framework will be helpful to assess the impacts of urbanization on natural habitats in a more effective way.