洞庭湖湿地植被系统的碳贮量及其分配

利用生物量调查和实验数据.对洞庭湖湿地植被生态系统的碳密度、碳贮量及其分配进行研究.结果表明:乔木层植被碳密度为15.607～40.501 t/hm~2,草本层植被为5.906～21.632 t/hm~2.水生植物植被1.460～3.492 t/hm~2,平均14.954 t/hm~2比温带地区湿地植物碳密度高;未受干扰草甸土壤碳密度为260.510 t/hm~2,每年收获产品草甸是185.492 t/hm~2,林地234.513 t/hm~2,水生植物土壤为206.882 t/hm~2,低于全国湿地土壤平均值.碳贮量分配中.植被层、凋落物层和土壤层的碳贮量分别占各植被类型系统碳的总贮量的0.47%～14.69%,0.29%～1.10%和84.54%～99.53%.每年收获部分产品的草甸土壤碳密度只有未受人为干扰草甸的71.2%,原生草本植物草地改造成林地后,6年的时间,土壤的碳密度减少了10%.因此,控制人为干扰,防止湿地破碎化、保护好湿地、保证湿地的固碳潜力,是湿地管理中应该优先考虑的问题.

Carbon Storage of the Wetland Vegetation Ecosystem and Its Distribution in Dongting Lake

Based on the investigation of biomass and the experimental data,carbon density,carbon storage and its distribution of the wetland vegetation ecosystem in Dongting Lake were studied.The results showed that the carbon density of the tree layer vegetation was 15.607-40.501 t/hm~2 of herbaceous layer vegetation was 5.906-21.632 t/hm~2,of aquatic vegetation was 1.460~3.492 t/hm~2,And the average carbon intensity of them was 14.954 t/hm~2;which is higher than wetland plants in temperate regions.Meanwhile.the soil carbon density of the undisturbed meadow was 260.510 t/hm~2,of the annual harvest of products meadow was 185.492 t/hm~2,of the woodland was 234.513 t/hm~2,and of the aquatic plants and soil was 206.882 t/hm~2.All of them were lower than that of the national average of wetland soil.For the distribution of carbon storage,the carbon storage of vegetation layers,litter layer and soil layer accounted for 0.47%～14.69%,0.29%～1.10%and 84.54%-99.53%of total carbon storage of different types of vegetation systerns.The carbon density of the annual harvest of some products meadow soil only was 71.2 percent of that of the undisturbed meadow.After the grassland with herbaceous plants had been changing into native forest,the soil carbon density had decreased by 10%in six years.Therefore,controlling man-made interference,preventing the fragmentation of wetlands,protecting wetlands,and being ensured the carbon sequestration potential of wetlands should be given priority consideration in wetlands management.