半干旱沙区退耕还林对碳储量和分配格局的影响  

Effects of farmland afforestation on ecosystem carbon stock and its distribution pattern in semi-arid region of Northwest China

作　　者：白雪爽[1] 胡亚林[2] 曾德慧[2] 蒋志荣[1] 

机构地区：[1]甘肃农业大学林学院,兰州730070 [2]中国科学院沈阳应用生态研究所

出　　处：《生态学杂志》2008年第10期1647-1652,共6页Chinese Journal of Ecology

基　　金：国家科技支撑计划项目(2006BAD26B0201-1);辽宁省生态公益林经营管理重点实验室开放课题基金资助项目(07ZDS111S1)

摘　　要：以农田和不同退耕还林年限（5、10、15年）的杨树人工林为对象，开展了退耕还林对生态系统有机碳储量和分配格局特征的研究。结果表明：随着退耕年限的增加，生物量碳储量不断积累，且其增加的碳库主要分配在树干。与农田（CK1）相比，退耕还林5年的杨树人工林（Poplarl）0～10、10～20、20～40和40～60cm土壤有机碳含量分别下降了7．65％、36．66％、51．94％和21．4％；退耕还林10年的杨树人工林（Poplar2），不同层次土壤有机碳含量分别提高了69．63％、62．46％、17．07％和66．94％。与农田（CK2）相比退耕还林15年的杨树人工林（Poplar3），0～10、20～40和40～60cm土壤有机碳含量分别提高了31．96％、81．50％和58．05％，而10～20cm土层下降了13．38％。与对照农田相比，5年生杨树人工林0～60cm土壤有机碳储量下降了31％，而10年和15年生杨树人工林土壤有机碳储量分别增加了47％和41％。退耕5年的杨树人工林总的碳储量比对照农田下降了10％，退耕10年和15年的杨树人工林与相应对照农田相比较，生态系统总的碳储量分别提高大约2倍和5倍。说明，农田退耕还林后生态系统碳储量明显增加，增加的碳储量主要积累在地上生物量碳库中。退耕还林初期，土壤有机碳储量表现出下降趋势，随后逐渐恢复甚至高于农田土壤碳储量。Taking the farmlands under different years （0, 5, 10, and 15 a） of poplar afforestation in semi-arid region of Northwest China as test objects, this paper studied the effects of farmland afforestation on the ecosystem carbon （C） stock and its distribution pattern. The results showed that with increasing year of afforestation, the biomass C increased gradually, and most of it was allocated in tree stem. Compared with the control （ CK1 ）, the soil organic C content in 0-10, 10-20, 20-40, and 40-60 cm layers after afforested for 5 years was decreased by 7.65%, 36.66%, 51.94%, and 21.4%, while that after afforested for 10 years was increased by 69.63%, 62. 46% , 17.07% and 66.94%, respectively. After afforested for 15 years, the soil organic C content in 0- 10, 20-40 and 40-60 cm layers was increased by 31.96% , 81.50% , and 58.05% , respectively, but that in 10-20 cm layer was decreased by 13.38% , compared with the control （CK2）. The C stock in 0-60 cm soil layer was decreased by 31% after afforested for 5 years, but increased by 47% and 41% after afforested for 10 and 15 years, respectively. The total C stock in 5 year-old poplar plantation was decreased by 10%, but that in 10- and 15-year-old poplar plantations was 3 and 6 times of the farmland. It was indicated that after farmland afforestation with poplar, the ecosystem C stock increased significantly, and most of the increased C was allocated in aboveground biomass C pool. At the early stage of afforestation, soil organic C stock tended to decrease, but thereafter, this stock increased gradually and was even higher than the control.

关 键 词：半干旱区 退耕还林 碳储量 分配格局 

分 类 号：S718.5[农业科学—林学]