鄱阳湖典型苔草湿地生物量季节变化及固碳功能评价

为进一步评估鄱阳湖湿地碳平衡，量化湿地固碳功能，于2009年9月～2011年5月，在鄱阳湖南矶湿地国家级自然保护区，选择以灰化苔草为建群种的洲滩湿地，采取收获法测定了灰化苔草4个生长季的地上、地下生物量及净初级生产力(NPP)。结果表明：1）苔草地上、地下生物量均具有明显的季节变化模式，变化范围分别为14608～1 77067 、1 80627～4 03256 g/m2；地下生物量与地上生物量的比例变化范围为208～1744，平均值为519。2）苔草地上地下生物量、NPP均表现为春季高于秋季。3）受洲滩淹水时间影响，苔草生物量、NPP具有显著的年际差异， 2010～2011年度苔草NPP仅相当于2009～2010年度的625%；NPP的下降地上部分较地下部分更明显。4）鄱阳湖湿地苔草固碳潜力巨大，2个年度固碳量分别为1 92383，1 23121 gC/m2

SEASONAL VARIATION IN PLANT BIOMASS OF CAREX CINERASCENS AND ITS CARBON FIXATION ASSESSMENT IN A TYPICAL POYANG LAKE MARSHLAND

To evaluate carbon balance of Poyang lake wetland and quantify its carbon fixation function,aboveground and belowground plant biomass,as well as the net primary productivity(NPP)were measured by harvest method in a marshland dominated by Carex cinerascens in the Poyang Lake Nanji Wetland National Nature Reserve from September 2009 to May 2011.Results indicated that both aboveground and belowground biomass showed clear seasonal variation pattern,ranging from 146.08 to 1 770.67 g/m2,and 1 806.27 to 4 032.56 g/m2,respectively.Ratio of belowground to aboveground biomass varied from 2.08 to 17.44,with mean of 5.19.All the values of aboveground biomass,belowground biomass and NPP were higher in spring than those in autumn.Moreover,the flood time of marshland largely influenced the NPP of Carex cinerascens,NPP in year from 2010 to 2011 accounted for 62.5% of year from 2009 to 2010,and aboveground biomass decreased more markedly in contrast to belowground.Carex cinerascens in Poyang lake marshland has large carbon fixation capacity,with carbon fixation of 1 923.83 and 1231.21 gC/m2 in the two year,respectively.