三江平原毛果苔草湿地光辐射能的利用与分配

THE UTILIZATION AND DISTRIBUTION OF THE SUNLIGHT RADIATION ENERGY IN CAREX LASIOCARPA WETLAND IN SANJIANG PLAIN

毛果苔草湿地的物理过程观测设在中国科学院三江平原沼泽湿地生态实验站内 ,用美国CID公司出品的光合仪对典型湿地中几种优势植物的光合能力进行测定 ;在 80℃干燥的植物样品 (含各种不同的构件 ) ,粉碎后 ,分别称量约 1g左右 ,用美国公司Parr型氧弹式热量计测定 ;研究发现毛果苔草湿地建群种中毛果苔草的净光合速率最大 ,为 4 7 4 1μmol/m/s。以太阳总辐射能和生长季内光合有效辐射为基础计算出各器官的能量利用效率计 ,极大值是细根 ,分别为l 394 5 %和 3 1879% ,极小值是穗 ,分别为 0 0 0 2 0 %和 0 0 0 4 6 % ,毛果苔草种群的能量利用率为2 5 4 %。湿地不同植物群落地下部分的能量含量分布中毛果苔草群落的地下部分能量含量的平均值最大。这说明毛果苔草种群具有较高的能量转化效率 ,并将大部分能量储存在地下部分。在不同层次的能量含量分配中 ,随着土壤深度的增加 ,地下部分的能量含量趋于递减。

Carex lasiocarpa is a rhizomatous clonal species of mire wetland in Northeastern China. The field studies about physical process of Carex lasiocarpa wetland was carried out in the Shangjiang Plain Mire Wetlands Ecological Experiment Station(47°31′N, 133°31′E)of the Chinese Academy of Sciences. The sampling area is 200×450m2 and was divided into three areas including the determined area of biomass, the determined area of wither biomass and the decompose area. Samples were taken 30 days once during May and October in 1998 and 1999. Sampling area was 1×1m2 and 2 to 3 replicates for each. The plants were divided into different components including leaf, sheath, rhizome,inflorescence, spike,radicula and dead standing. All samples were ground into pieces and dried to constant weight at 80℃ for analysis. The energy content is determined by bomb carlorimeter(Parr, USA). The photosynthesis is determined by photosynthesis meter(CID company, USA)The results showed that the net photosynthesis rate of Carex lasiocarpa(47.41 μ mol/m/s)is faster than those of other plants in Carex lasiocarpa wetland, Based on the overall sunlight radiation and the efficient photosynthesis radiation, energy utilization rate in radicula was the highest(1.3945% and 3.1879%)While those in spike was the lowest(0.0020% and 0.0046%). Energy utilization efficiency of Carex lasiocarpa population is 2.54%. The average energy content of underground components of Carex lasiocarpa community is bigger than those in other community. It showed that C. lasiocarpa had higher energy productive efficiency and most energy was stored in their underground part. Energy contents in underground components decreased with the increase in depth in soil.