Temporal-spatial differentiation and its change in the landscape ecological security of Wuyishan Scenery District

Located in the northwestern part of Fujian Province,Wuyi Mountain is the most outstanding area for biodiversity conservation in southeast China and a refuge for a large number of ancient,relict species,many of them endemic to China.In December 1999,Wuyi Mountain was included on the World Natural and Cultural Heritage List by the 23rd Session of the World Heritage Committee of UNESCO and described as "a natural landscape so unique,rare and marvelous, is the beauty of nature and embodiment of the harmonious relations between human being and environment". Wuyi Mountain is now the largest of China′s World Heritage sites,which together cover 999.75 square kilometers.Wuyi Mountain is divided into four areas,the Biodiversity Preserve to the west,the Nine-twist Stream Ecological Preserve in the center,the Natural Beauty Cultural Landscape Preserve to the east(i.e.Wuyishan Scenery District),and the ancient Chencun Minyue Relics to the southeast. Landscape patterns embody both landscape heterogeneity and the accumulation of ecological processes.Changes in landscape patterns and their distributions are comprehensive reflections of the ecological environment,which is impacted by both natural disturbance and human intervention.Where human activities dominate landscapes,the impacts of our different uses and usage intensities in different landscape types ultimately reflect ecosystem or landscape structures and patterns.Changes of large-scale structure and pattern can change landscape ecological security in time and space.Therefore,the landscape level is an appropriate scale at which to study the impacts of human activities on the environment. Although all four of the Wuyi Mountain regions have been well protected in accordance with the strict management criteria for a world heritage site,the Wuyishan Scenery District has been more severely disturbed than the other three regions.In this study,the degree of landscape ecological security was established based on landscape disturbance and fragility indices.Spatial statistics were used to evaluate the temporal-spatial differentiation and patterns of change of ecological security in 1986,1997 and 2009.The results show that between 1986 and 2009,the ecological security degree gradually increased in Wuyishan Scenery District.Moran′s I showed positive spatial autocorrelation,and this correlation was most apparent between 1986 and 1997.The general autocorrelation of landscape ecological security degree had a scaled response.Between 1997 and 2009,the local autocorrelation pattern was consistent.However,the cluster structure and significance level of ecological security degree obviously changed between 1986 and 1997.The strong spatial correlation of ecological security degree resulted from the combined influences of structural and non-structural factors.Structural factors such as topography,landform and agrotype had significant impacts on spatial distribution.Non-structural factors,including tourism,development and construction,reclaiming forest land,and shifting farmland to tea plantations,strongly influenced changes in spatial distribution.