NITROGEN AND PHOSPHORUS CONTENT OF VASCULAR PLANT SPECIES IN HERBACEOUS MARSHES IN THE SANJIANG PLAIN, NORTHEAST CHINA

摘要

The stoichiometry of wetland plant species has been investigated in Europe and North America, but few correlative studies have been conducted in northeast China. A systematic census of plant nitrogen (N) and phosphorous (P) concentrations and N:P ratios by biomass was conducted for 21 characteristic species from Carex and Phragmites marsh in nine marsh sites of the Sanjiang Plain, northeast China. The means of N, P, and N:P ratios were 11.87, 1.42 mg g~(-1), and 8.69, respectively. Compared with European and American studies, the lower N content is the primary difference in the N and P stoichiometry of wetland species in northeastern China. Critical nutrient concentrations and N:P ratios are used to determine nutrient limitations and these indicators suggest N deficiency in this region. Inter-species and inter-plant group variations in N, P, and N:P ratios differed. This study is a contribution to understand the stoichiometry pattern of global wetland plant and for the management of wetland ecosystem in Sanjiang Plain, Northeast China.