Spatial Heterogeneity Relationship Of Vegetation And Environmental Factors In Wuyi Mountain

In this study, a variety of methods were used to explore the spatial heterogeneity of vegetation and environmental factors and their relations in the world heritage of Wuyi Mountain based on the higher resolution of TM remote sensing image and DEM, temperature, precipitation, roads, rivers and residents distribution map. The main results are as follows:(1)The mean of NDVI in each environment gradient interval was computed. Results show that NDVI has obvious spatial heterogeneity along the elevation, slope, and aspect gradient, the follows are temperature and precipitation, whereas small spatial differentiation along the distance to the nearest resident, distance to the nearest road and distance to the nearest river gradient. Below the altitude of 1350m, NDVI is positively associated with elevation and precipitation, is negatively associated with temperature. Above the altitude of 1350m, NDVI is negatively associated with elevation and precipitation, is positively associated with temperature. NDVI reaches the maximum in the in southeast slope and slope.(2)The continuous wavelet transform and wavelet variance of two perpendicularly intersect transects were used to examine the scale effect of the spatial heterogeneity of NDVI and environmental factors. Results show that the mainly distribution pattern of vegetation is independent of mountain unit. Wavelet coherency was used to further explore the relationship between NDVI and environmental factors at different scales and locations. Results show that the correlation between NDVI and environmental factors is strongest at 120-5760m scale as a whole, and smaller at less than 120m scale and 5760-7680m scale. Elevation is the decisive factor for the distribution pattern of vegetation in the world heritage of Wuyi Mountain. The correlation between NDVI and natural factors (including topography and the distance from recent rivers) along the longitudinal transect is stronger than that long the latitudinal transect. Whereas the correlation between NDVI and human activities((including the distance to the nearest resident and distance to the nearest road) along the longitudinal transect is weaker than that along the latitudinal transect. There is positive correlation between NDVI and slope, distance to the nearest resident, distance to the nearest road, and distance to the nearest river in low elevation areas, and negative in high elevation areas. NDVI is negative related with elevation in the north and west of tall mountains, while positive in the south and east.(3) Spatial autocorrelation analysis was used to explore the spatial dependence, heterogeneity, and coincidence of vegetation and environmental factors in the whole region at independent of mountain scale. Results show that NDVI and all environmental factors except aspect have significant characteristics of spatial cluster. The rank of each factor for vegetation from better to less is temperature, precipitation, elevation, slope, distance to the nearest resident, distance to the nearest road, distance to the nearest river and aspect. High vegetation coverage areas are located in Wuyi Mountain National Nature Reserve, and low vegetation coverage areas are located in the mid-lower reaches of Jiuqu Stream and Chongyang Stream coast. There is a kind of coupling relationship between NDVI and temperature, precipitation, elevation, slope, distance to the nearest resident.