三江平原小叶樟、毛果苔草枯落物中氮素变化分析

以三江平原沼泽湿地主要优势植物小叶樟(Deyeuxiaangustifolia)和毛果苔草(Carexlasiocarpa)枯落物为例，探讨了N素在枯落物中的季节变化、含量特征以及对维持生态系统物质平衡的作用．结果表明，枯落物N含量随气温升高和地上生物量增大而减少；枯落物失重率随时间延长而增大；小叶樟年累积失重率为32．2％，毛果苔草为27．7％；小叶樟群落N素年累积输入量为1478mg

Nitrogen content variation in litters of Deyeuxia angustifolia and Carex lasiocarpa in Sanjing plain

This paper dealt with the litter of two dominant species Deyeuxia angustifolia and Carex lasiocarpa in swamp of Sanjiang Plain, and analyzed the seasonal variation and content feature of nitrogen in litter and its roles on maintaining matter equilibrium in ecosystems. The nitrogen content in litter decreased with the increasing temperature and above-ground biomass. The weightlessness rate of litter increased with time, and the annual accumulative weightlessness rates of D. angustifolia and C. lasiocarpa were 32.2% and 27.7%, respectively. The annual accumulative nitrogen input amount of D. angustifolia community was 1478 mg.m-2, C. lasiocarpa 587 mg.m-2, while the annual accumulative nitrogen output amount in litter of D. angustifolia community was 759 mg.m-2, C. lasiocarpa 410 mg.m-2. It was suggested that the nitrogen input amount was higher than output, and that the state of nitrogen accumulation was beneficial to the stability of the ecosystems.