Abstract: To study the regional ecological risk under landscape pattern change can provide important scientific basis for protecting the health of regional landscape ecosystem and realizing the reasonable and sustainable utilization of regional resources. Selecting Zhalong Nature Reserve as study area, and using remote sensing to obtain the information of landscape types, this paper quantitatively analyzed the characteristics of the spatiotemporal change of the Reserve’s landscape pattern and its evolution in different spatial scales. According to the characteristics of the landscape change, the index of the landscape ecological risk was established, and the spatiotemporal change characteristics of the landscape ecological risk under spatial scale change in different periods were analyzed. From 1995 to 2010, the overall landscape pattern and the pattern of each landscape type in the Reserve changed significantly in different scales, and showed different change characteristics. The landscape ecological risk in the study area decreased with the increase of spatial grain. The comparative analysis of the data in two different periods showed that the landscape ecological risk in the Reserve increased, and the risk’s spatial distribution presented ring and diffusion characteristics. According to the size of the study area and the complexity of the landscape pattern, an appropriate scale domain for the research on landscape pattern and landscape ecological risk was determined.  

Key words: soil organic carbon, total nitrogen, soil enzyme activity, microbial biomass carbon /nitrogen, microbial respiration.