[Spatial-temporal dynamics of landscape fragmentation in North Shannxi Loess Plateau]

The study of landscape fragmentation is an important means to reveal regional ecological processes. By using the remote sensing data of 1987, 1997 and 2002, and the GIS tools, some representative quantitative indices of the landscape spatial structure and landscape fragmentation in North Shannxi Loess Plateau were calculated, aimed to investigate the relationships between landscape ecological structure and landscape pattern in this area. The results showed that cropland contributed most to the extent of landscape fragmentation, but unused land lacked obvious relationship with it. To get large-area images accurately and promptly is very important for monitoring ecological process in regional scale. Moderate-Resolution Imaging Spectroradiometer (MODIS) images in 2003 were used to derive monthly landscape fragmentation information calculated with Local Index of Spatial Associations (LISA) based on Spatial Statistical Analysis (SSA). The analysis of the fragmented landscape types showed that human disturbance had a main contribution to the seasonal landscape fragmentation. Furthermore, with the increasing percentages of cropland and unused land, landscape became more fragmented, while forestland coverage had inverse effects on the fragmentation.