三江平原湿地主要优势植物枯落物分解过程与能量动态研究

Energy Dynamics and Decomposition Process of Litters of Main Plant Communities in Wetlands in the Sanjiang Plain

应用分解袋法对三江平原3种湿地植物小叶章(Calamagrostis angustifolia)、毛苔草(Carex lasiocarpa)和漂筏苔草(Carex pseudocuraica)枯落物分解过程及能量动态进行了研究。结果表明,随着分解的进行,3种湿地植物枯落物失重率呈增加趋势,平均失重率从高到低的顺序是:漂筏苔草[(23.20±5.92)%]、小叶章[(22.85±5.09)%]、毛苔草[(21.47±4.88)%]。枯落物干重热值呈降低的变化趋势,分解初期干重热值降低的速率较大,随分解的进行,干重热值变化趋于平缓。其平均干重热值从高到低的顺序是:漂筏苔草[(16696.22±459.35)J/g]、小叶章[(16575.39±522.36)J/g]、毛苔草[(16488.46±227.79)J/g]。枯落物能量损失率呈增加的趋势,平均能量损失率从高到低的顺序是:漂筏苔草(26.54%)、小叶章(26.39%)、毛苔草(24.10%)。相关分析研究表明,能量损失率与失重率之间具有极显著的正相关关系(n=24,p<0.01),而与干重热值之间呈显著的负相关关系(n=24,p<0.01)。

In order to provide some basic foundation with the development of energy ecology of wetlands, the understanding needs to be deepen on the characteristic of energy flow during the decomposition of plant litter in mire- wetland in the Sanjiang Plain, China. The litter decomposition process and energy dynamics during the decomposition of Calamagrostis angustifolia, Carex lasiocarpa and Carex pseudocuraica litters were studied using mesh bags in the paper. The results showed that during the decomposition of 3 types of wetland plant litters, the weight loss rates were increasing. The rank order of the average weight loss rates were Carex pseudocuraica litter [ （23.20 ± 5. 92 ） % ], Calamagrostis angustifolia litter [ （ 22.85 ± 5.09 ） % ] and Carex lasiocarpa litter [ （21.47 ±4.88）% ]. The gross caloric values were decreasing in the process of decomposition, and they all decreased rapidly in the initial stage and slowly in the later stage. The mean average gross caloric values decreased from the Carex pseudocuraica litter [ （16 696.22 ±459.35 ） J/g], to the Calamagrostis angustifolia litter[ （ 16 575.39 ± 522.36） J/g ] and to the Carex lasiocarpa litter [ （ 16 488.46 ± 227.79 ） J/g ]. The energy loss rates were increasing in the whole decomposition process of the 3 wetland plant litters, the average energy loss rates of the Carex pseudocuraica litter was the highest, the second was the Calamagrostis angustifolia litter and the lowest was Carex lasiocarpa litter. They were 26.54%, 26.39% and 24.10%, respectively. There were remarkably significant positive correlation between energy loss rates and weight loss rates （n = 24 ,p 〈 0.01 ）, with significant negative correlation between energy loss rates and gross caloric values（n = 24 ,p 〈0.01）.