Land Use Changes In Zhalong Nature Reserve And Evaluation Of Landscape Connectivity For Red-crowned Crane Habitat

One of the key problems in contemporary ecology and conservation biology is the drastic changes of landscapes induced by anthropogenic activities, especially habitat loss and fragmentation. The primary way of species conservation is protecting their habitats, so the study on habitat changes and fragmentation of species is very important.The red-crowned crane is an endangered species, first class of national key protection birds. Zhalong Nature Reserve is its important breeding habitat, but the land use and landscape pattern changed greatly in recent years and was impacted by human activities and biophysics factors, which affected the quality and distribution pattern of the red-crowned crane habitat.Our study area is in Zhalong Nature Reserve. Using 3S technology (GIS, RS, GPS), by the interpretation of satellite remote sensing imagines of 2004 and 2013, the functional regionalization map, topographic map, external investigation data and the red-crowned crane nesting locations was integrated. The land use changes amount and spatial distribution of Zhalong Nature Reserve were analyzed by using land use change dynamic degree and land use change transition matrix.Based on landscape connectivity principles and methods, landscape connectivity influence factors of red-crowned crane nesting habitat were analyzed. The suitability of the red-crowned crane habitat was evaluated using the land use data, and habitat suitability index were obtained. The red-crowned crane nesting location was counted as "source" and the suitable habitat as "sink" of ecological process, then the landscape connectivity of the red-crowned crane nesting habitat was evaluated using connectivity index. The structure characteristics of the red-crowned crane nesting habitat was analyzed by landscape structure index and the change trend of fragmentation was discussed.The results showed:(1) landscape pattern:the mixed landscape was composed of reed swamp marsh, cropland, grassland, constructive land, saline land, lakes and the reed swamp marsh is dominant type. The basic spatial distribution pattern indicated that the reed swamp marsh was distributed in internal and cropland, grassland, saline land showed a mosaic distribution in edge of nature reserve.(2) land use changes:the area of reed swamp marsh, lakes, constructive land and cropland increased, while grassland and saline land decreased. Constructive land increased fastest among other land uses. The reed swamp marsh was stable and changed in the lowest dynamic degree. The changes of edge part were more intense than the internal parts in the perspective of land use change transition.(3) landscape connectivity evaluation:from 2004 to 2013, the proportion of the area with high connectivity changed from 24% to 20%; the area with relative high connectivity changed from 17% to 15%; the area with general connectivity changed a little.(4) breeding habitat fragmentation:the area of the red-crowned crane nesting habitat changed a little, while its shape changes greatly. From 2004 to 2013, the FRAC_MN、 CONTAG and CIRCLE increased and the PARA_MN decreased, all these changes in landscape structure shape index showed that fragmentation of the red-crowned crane nesting habitat trended seriously.