With more than half of the world’s population living in cities, the importance of understanding the urban ecosystem and the effect of urbanization on the environment has been increasingly recognized. Urbanization has caused some negative impacts on the environment, such as the introduction of exotic species, the fragmentation of habitats, and the alternation of ecosystem processes. This study adapted a combined method of urban gradient analysis and landscape metrics to analyze the changes of landscape pattern in Dane County, Wisconsin, in relation to the degree of urbanization. Spatially, a 60 km transect cutting through the City of Madison was set up in the study area, representing a continuum of rural-urban-rural landscapes. Temporally, historical land-use data were compiled in GIS format every decade from 1970 to 2000. Changes of landscape pattern were analyzed by FRAGSTATS with six metrics—percentage of landscape, Shannon’s evenness index, patch density, mean patch size, edge density, and shape index. The behavior of landscape metrics varied among different metrics and different land-use types.
Overall, the results revealed an increase in landscape heterogeneity, fragmentation, and complexity paralleling the degree of urbanization. The trend of change was consistent both spatially and temporally. The changes of landscape pattern are closely related to urban development and regional population growth. In the past three decades, urban development has been directed to areas adjacent to existing developed areas for a compact form of development promoted by regional land-use plans. The study demonstrated the application of landscape metrics to the analysis of urban landscape pattern. This approach has huge potential in the monitoring and assessment of ecological consequences of urbanization and can assist urban environmental design with the aim to mitigate negative effects of urbanization on the urban ecosystem.
Summary Table of Results