以秦岭火地塘林区油松和漆树倒木为研究对象,采用国际倒木腐烂等级划分方法,测定其5个腐烂等级的6种化学元素(C,N,P,K,Ca,Mg)的含量,分析倒木对土壤化学元素的影响.结果表明:油松倒木5个腐烂等级间C含量没有显著差异,而漆树倒木C含量随着分解显著递减；漆树和油松V级倒木的N含量随着分解显著递增；Mg含量在油松倒木分解过程中无显著差异,在漆树倒木分解后期显著增加；P,K,Ca含量在漆树和油松分解过程中都无显著差异,但P和Ca含量随着油松和漆树倒木的腐烂呈线性增加,K含量随油松和漆树倒木分解呈线性下降.油松和漆树倒木下土壤C含量随着土层加深而显著减少,K,Ca,Mg含量随土层加深无显著差异；土壤C含量随倒木腐烂显著递增,N,P,Ca,Mg含量随倒木分解无显著差异.该研究揭示倒木分解过程中各种化学元素的变化规律,对促进秦岭森林生态系统物质循环和制定林木更新措施有重要的参考价值.%Fallen woods of Pinus tabulaeformis and Toxicodendron vernicifluum were used to study the decomposition process. According to an international classification, nutrient contents of 6 elements ( C, N, P, K, Ca, Mg) in five decomposition classes were measured in Huoditang forest region in the Qinling Mountains, and the elements in the soil were also analyzed. The results showed that there were no significant differences among C contents in the decay classes of P. Tabulaeformis, but the C content of T. Vernicifluum decreased significantly with decaying. N obviously accumulated in the V decay class in P. Tabulaeformis and T. Vernicifluum. There was no significant difference in Mg among the decay classes in P. Tabulaeformis, while Mg significantly increased at the late stage of decomposition in T. Vernicifluum. No differences were found in P, K and Ca among the decay classes of P. Tabulaeformis and T. Vernicifluum, however with the decomposition of P. Tabulaeformis and T. Vernicifluum, the contents of P and Ca linearly increased, the content of K linearly decreased. With the increase of soil depth, the content of soil C under fallen wood decreased significantly, however no difference was observed in K, Ca and Mg. The content of soil C increased significantly from decay I to V , while the N, P, Ca and Mg were similar. This research reveals the change pattern of various nutrients during the decomposition process of fallen wood, which would be helpful for measurement - making of promoting the nutrient cycling and forest regeneration of forest ecosystems in the Qinling Mountains.
展开▼
