Application of a revised Gash analytical model to simulate subalpine Quercus aquifolioides forest canopy interception in the upper reaches of Minjiang River Rainfall redistribution in subalpine Quercus aquifolioides forest in upper reaches of Minjiang River. Variations of Soil Nitrogen and Microbial Biomass Carbon and Nitrogen of Quercus aquifolioides Forest at Different Attitudes in Balangshan, Sichuan