高寒沙区小叶锦鸡儿凋落物对土壤肥力的影响

Influence of the litter decomposition of Caragana microphylla on soil fertility in alpine desert area

为了解高寒沙区凋落物分解过程中土壤的基本状况,测定青海省沙珠玉荒漠人工植被恢复区中小叶锦鸡儿凋落物下的土壤随凋落物的分解,其有机质,N,P,K的含量变化。结果表明:各样地的土壤中全磷含量差异较小,有机质以及其他土壤元素含量差别较为明显,随着林龄的增加,土壤元素含量整体上呈上升趋势,丛下含量高于丛间,且随着样地林龄的减小,丛下和丛间土壤条件的差距也在减小;土壤有机质和全氮含量表现为富集-释放-富集模式,碱解氮、速效磷、速效钾含量的变化表现为净含量的富集,全钾含量变化呈现反复积累和释放的过程,全磷含量变化不明显。小叶锦鸡儿凋落物是研究区土壤肥力的主要来源,且恢复年代越久远,对土质改善的贡献越大,除此之外,丛下土壤条件要好于丛间。

In order to understand the basic situation of the litter decomposition in soil of old desert area,the content of organic matter,nitrogen,phosphorus,potassium element during the process of litter decomposition which derived from Caragana microphylla in Shazhuyu artificial vegetation restoration zone of Qinghai were measured. The results show that the total soil phosphorus content differences between five experimental plots are small,but differences of organic matter content and other soil elements are evident. Soil element contents are increasing with the age of Caragana microphylla as a whole. The contents,under clusters are higher than between＇s and decreasing with forest age.The content differences of under- cluster and between- cluster are decreasing with forest age as well. Soil organic matter and total nitrogen content exhibit enrichment- release- enrichment patterns. The alkaline hydrolysis nitrogen,available phosphorus and available potassium contents show net enrichment. The total potassium content appears repeatedly accumulation and release process,and the total phosphorus content is not obvious.