Water Conservation Assessment and Spatial Analysis of Forest Soil in Wuyi Mountain National Nature Reserve

Wuyi Mountain National Nature Reserve in Fujian Province was chosen as the case study area,the quantity of forest soil water conservation in the study area was estimated and its spatial distribution was analyzed by means of INVEST model based on the field survey data from 24 permanent sampling plots in 2003, the climate observation data of the oriented ecosystem research station in 2003 and the Landsat TM remote sensing data collected on October 5, 2003. The study showed that the average depth of forest soil water conservation in 2003 was 204.135 mm, and the total amount of water conserved by the forest soil was 105.187 2 million cubic meters in 2003. The depth of forest soil water conservation in the nature reserve in 2003 was spatially aggregatively distributed, but the spatial distribution of the forest soil water conservation depth in the core zone, buffer zone and experimental zone in the reserve became less aggregative but more fragmented along with the decrease of elevation and increase of human disturbance.The forest stands with deeper soil water conservation were usually located at sites with higher elevation, steeper slope, higher soil moisture and poorer vegetation growth condition.The spatial distribution of the depth of forest water conservation showed a sloping stripe trend from northeast to southwest. The average values of correlation coefficients between the depth of forest soil water conservation and elevation, gradient, soil moisture was 0.206 5, 0.629 5 and 0.357 0, respectively, indicating that the depth of forest soil water conservation was positively correlated with the three dependent variables.