鄂西南七姊妹山两种泥炭藓湿地土壤 有机碳分布特征的对比研究

Distribution characteristics of soil organic carbon of the sphagnum wetland in Qizimei Mountains of southwestern Hubei

摘要:

研究泥炭藓湿地土壤有机碳含量有助于从土壤肥力角度了解湿地土壤的发育状况, 同时有助揭示区域碳循环过 程 。本研究选取鄂西南七姊妹山泥炭藓发育完好湿地与泥炭藓开采退化后湿地为采样点,分析土壤有机碳(SOC)分布规 律及其含量的差异 。结果表明:①七姊妹山泥炭藓湿地土壤有机碳含量存在明显的垂直分布规律,土壤有机碳含量随土壤 深度的增加呈指数函数递减,土壤有机碳碳含量为 28. 75~377. 72g ● kg -1 ,有机碳密度为 19. 18~56. 06kg ● m -3 ;②泥炭 藓湿地土壤有机碳含量在水平方向也存在一定的分布规律,湿地中心土壤有机碳含量高于其它区域;③泥炭藓的开采使土 壤有机碳含量显著减小,泥炭藓开采退化后湿地土壤有机碳含量仅为泥炭藓发育完好湿地的 31%,土壤有机碳密度为泥炭 藓湿地的 65% 。泥炭藓在固定土壤有机碳与湿地碳循环中发挥重要作用,应该加强泥炭藓的保护,控制泥炭藓的开采。

Abstract:

The research on soil organic carbon content in sphagnum wetland will be helpful to understand the develop- ment of wetland soil from the perspective of soil fertility, and also be beneficial for revealing the regional carbon cycle . In this study, a sphagnum—covered wetland and a sphagnum— removed wetland were selected in Qizimei Mountains in southwest Hubei province . The spatial distribution of soil organic carbon in the two sites were studied and the difference between them were compared. The results were showed that : ①obvious vertical distribution characteristics of soil organic carbon content were found both in the sphagnum—covered site and in the sphagnum—removed site; and soil organic car- bon content declined in the way of exponential mode with the increase of soil depth ; and the soil organic carbon content in the sphagnum— covered wetland ranged from 28. 75 to 377. 72 g ● kg—1 and the soil organic carbon density ranged from19. 18to 56. 06kg ● m—3 ; ②In the sphagnum—covered wetland, soil organic carbon content showed a difference in the distribution in the horizontal direction, and soil organic carbon in wetland center is higher than those in the other are- as ; ③Remarkable reduction in soil organic carbon content was found after sphagnum was removed from the wetland, soil organic carbon content of the sphagnum—removed wetland was only 31% of the sphagnum— covered wetland, and soil organic carbon density was 65% of that in sphagnum — covered wetland. The results showed that the importance of sphagnum wetland on soil organic carbon and carbon cycling in wetlands . Thus, the conservation of sphagnum—covered wetland should be taken consideration and adopt measures to reduce the exploitation of sphagnum.