A Simulation Model for the plant-Environmental System of Alkalized Grassland on Songnen Plain in Northeast China APPLICATION OF COMPUTERS TO BOTANY Root biomass and its spatial distribution of Bruguiera gymnorrhiza in the mangrove of Shenzhen Bay, South China STUDIES OF CONTINENTAL AQUATIC VEGETATIONS IN CHINA: A REVIEW Clonal Growth in Plants in Relation to Resource Heterogeneity:Foraging Behavior