The Analysis of Energy Flux Process of Carex lasiocarpa Wetland in Sanjiang Plain The accumulation,allocation and biological cycle of the nutrient elements in Carex lasiocarpa wetland Responses of Carex lasiocarpa clonal reproduction to water regimes at different growth stages Dynamics of litter and under-ground biomass in Carex lasiocarpa wetland on Sanjiang Plain Fractal relationship between aboveground biomass and plant length or sheath height of Carex lasiocarpa population