Genetic diversity and genetic structure in Sassafras tsumu populations along altitudinal gra-dients in Tianmushan Mountain, China. STUDIES ON THE ROOT EFFECT OF THE MIXED FOREST OF CUNNINGHAMIA LANCEOLATA AND SASSAFRAS TSUMU Relationships of Leaf Color and Pigment and Nutrient Elements in Senescing Leaves of Sassafras tsumu Study on the inter-species competition of Sassafras tsumu community in the mid-subtropics and the population density adjustment Bamboo rhizome system of mixed forest of Sassafras tsumu and Phyllostachys pubescens Study on the Biomass and Soil Fertility of Pure and Mixed Stands of Cunninghamia lanceolata,Liriodendron chinense and Sassafras tsumu