Extent effect of landscape gradient analysis of urban-rural transect

With the combination of gradient analysis and quantitative analysis of landscape pattern,and by changing the transect width and research step,the extent effect of landscape gradient analysis of an urban-rural transect were studied.The results showed that the landscape gradient analysis of the urban-rural transect was scale-dependent,and the effect of transect width was greater than that of research step.Research step mainly affected the fluctuation degree of each landscape index along transect,and it was appropriate for the transect to be divided equally into 20 samples.There existed critical values for transect width.When the transect width was beyond the values,the fluctuation trend of each index along transect would be varied.Furthermore,different landscape metrics responded differently to the same transect.The percent coverage and edge density of each class,as well as the Shannon's diversity index of landscape,showed significant gradient characteristics,while patch density and mean patch fractal dimension were in adverse.