土地利用方式对土壤活性碳库和碳库管理指数的影响

Effect of land-use type on soil labile carbon pool and carbon management index

以江西省安福县15年利用历史的撂荒地和3种林地(毛竹人工林、木荷次生林、杉木人工林)等土地利用方式为研究对象,探讨土地利用方式对活性有机碳库以及碳库管理指数的影响。结果表明:(1)不同样地土壤活性有机碳库的大小顺序为毛竹人工林(14.56 t·hm-2)>木荷次生林(14.41 t·hm-2)>杉木人工林(13.39 t·hm-2)>撂荒地(9.53 t·hm-2),3种林地均显著高于撂荒地。(2)土地利用方式转变成林地后土壤总有机碳含量、活性有机碳含量、稳定态碳含量、碳库指数均有大幅度提高,木荷次生林土壤碳库活度、碳库活度指数值均最大,毛竹人工林氧化稳定系数最大,以撂荒地作为参考计算出不同土地利用方式土壤碳库管理指数值,排列顺序为:木荷次生林(184.61)>毛竹人工林(172.58)>杉木人工林(150.50)>撂荒地(100)。(3)林地对土壤更具有培肥作用,处于良性管理状态,尤其以木荷次生林最佳。

To study the effect of different land uses on soil labile organic carbon pool and carbon management index （CMI） , four types of land use, including abounded land （AL） and three for- est lands [ Phyllostachys edulis forest （PE）, P. edulis and Schima superba secondary forest （ SS）, Cunninghamia lanceolata forest （CL） ] were selected in nnfu County, Jiangxi Province. The result showed that soil labile organic matter pools in the different land-use types were in the order of PE （14.56t·hm^-2） 〉 SS （14.41 t·hm^-2） 〉 CL （13.39 t·hm^-2） 〉 AL （9.53 t·hm^-2）, and the values in the forest lands were significantly higher than in AL. After the land use was changed to forest land, total soil organic carbon, soil labile organic carbon, stable car- bon content, carbon pool index were greatly improved ; the values of labile carbon and labile car- bon index were highest in SS, while the value of coefficient of oxidation stability was highest in PE. Taking AL as a reference, the CMI values of the different land-use types were in the order of SS （184.61） 〉 PE （172.58） 〉 CL （150.50） 〉 AL （100）. It is indicated that forest lands could function to improve soil fertility and were in good management situation, especially for SS.