Effects of simulated nitrogen deposition on lignin and cellulose degradation of foliar litter in natural evergreen broad-leaved forest in Rainy Area of Western China. Soil carbon pool and fertility under natural evergreen broad-leaved forest and its artificial regeneration forests in Southern Sichuan Province Biomass Allocation Between Aboveground-and Underground of shrub Layer Vegetation in Natural Evergreen Broad-Leaved Forest and Chinese Fir Plantation