[Nitrogen dynamics in different organs of Calamagrostis angustifolia and Carex lasiocarpa in Sanjiang plain].
The dynamics of nitrogen content and storage in different organs of Calamagrostis angustifolia and Carex lasiocarpa which are dominant vegetation in swamp wetland were determined, and the utilization rate of nitrogen and its nutrient limitation in the region were analyzed. The results showed that the aboveground and underground biomass might be described by p = gamma + alpha t + beta t2 and p = a0 + b0t, respectively. The content of total N, NH4(+)-N and NO3(-)-N varied widely with different organs because of the effects of soil water, nutrient content, atmospheric temperature, vegetable feature and selective absorption to nitrogen, etc. The content of NO3(-)-N in different organs varied less than that of NH4(+)-N, and NH4(+)-N/NO3(-)-N was < 1. The N:P content less than 14 in two vegetations showed that it was N but not P was the limitation nutrient to the growth of vegetation in this region, moreover, the limitation was less in July than in August. This conclusion was also drawn from the analysis of the NH4(+)-N and NO3(-)-N content in soil.
Sun
X
X
Chinese Research Academy of Environmental Sciences, Beijing 100012. sunxl@svr1-pek.unep.net or sunxf-1999@yahoo.com
Liu
J
J
Chu
Y
Y
D018533:Biomass; D002681:China; D029785:Cyperaceae / Q000254:growth & development / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D018547:Plant Stems / Q000378:metabolism; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism*; D014018:Tissue Distribution
D009584:Nitrogen