人工林凋落叶分解对土壤性质的影响

Effect of plantation litter decomposition on soil properties

【目的】研究人工林凋落叶分解对土壤性质的影响,为防止土壤退化、增加土壤肥力提供理论指导。【方法】采集四川岷江流域上游的4种(连香树(Cercidiphyllum japonicum)、云南松(Pinus yunnanensis)、糙皮桦(Betula1 utilis)和云杉(Picea asperata))林木凋落叶及林地土壤样品,通过对当年凋落叶进行240 d室内分解培养试验,探讨不同凋落叶在分解过程中对土壤性质的影响。【结果】云杉和云南松凋落叶分解使土壤pH值降低,糙皮桦和连香树凋落叶分解使土壤pH值增加;4种凋落叶分解过程中,土壤有机质和全氮含量,土壤微生物量C、N以及4种土壤酶(蔗糖酶、过氧化氢酶、脲酶和蛋白酶)活性均有所增加。【结论】土壤有机质、全N、微生物量、酶活性增加的幅度与凋落叶分解速率及养分释放率有密切关系,凋落叶分解的越快,土壤状况改善的越明显。

[Objective] The effect of litter decomposition of forests on soil characteristics were studied in order to prevent the soil degeneration and increase the soil fertility. [Method]Collected leaf litter and soil in four kinds of artificial forests （Cercidiphyllum japonicurn, Pinus yunnanensis, Betula utilis and Picea asperata） on the upriver of Minjiang River in Sichuan. Through decomposition experiments for 240 days in laboratory,the change of soil properties in the course of litter decomposition was comprehensively appraised. [Result] Decomposition of Picea asperata and Pinus yunnanensis leaf litter decreased the soil pH value. Decomposition of Betula utilis and Cercidiphyllurn japonicurn increased the soil pH value. In the process of leaf litter decomposition,the organic,total N,the content of microorganism biomass C （MB-C）, microorganism biomass N （MB-N） and the enzyme activity （catalase enzyme, urea enzyme, invertase enzyme and protease enzyme） of soil were increased. [Conclusion] There is a close relationship between the soil organic,total N,microorganism biomass C （MB-C）,microorganism biomass N （MB-N）,enzyme activity and the decomposition rate,C,N releasing rate of leaf litter. When leaf litter decomposed rapidly,the soil status improved in evidence.