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采用凋落物分解袋法,研究了土壤动物对四川盆地4种典型树种[油樟(Cinnamomum longepaniculatum)、马尾松(Pinus massoniana)、麻栎(Quercus acutissima)和柳杉(Cryptomeria fortune)]凋落叶在分解第一年(2013年11月—2014年10月)不同物候时期可溶性有机碳(DOC)和总可溶性氮(TDN)浓度动态的影响。结果表明,4种凋落叶均表现出DOC浓度降低、TDN浓度升高的趋势。土壤动物显著降低了凋落叶DOC含量而增加了TDN含量,且此现象分别在马尾松和柳杉凋落叶中最为明显。土壤动物对凋落叶中DOC含量的影响在叶衰期更明显,而对TDN含量的影响在秋末落叶期更明显。这些结果说明,土壤动物显著影响凋落叶分解过程中可溶性碳、氮动态,这为认识凋落物分解过程中氮固持现象提供了一定的理论依据。同时,土壤动物在生长季节降低凋落叶可溶性氮浓度,可能有利于满足植物在生长季节对养分的需求。
The litter decomposition method was used to study the effects of soil fauna on the litter of four typical tree species (Cinnamomum longepaniculatum, Pinus massoniana, Quercus acutissima and Cryptomeria fortune) in the Sichuan Basin Decomposition of the first year (November 2013-October 2014) of different phenological stages of soluble organic carbon (DOC) and total soluble nitrogen (TDN) concentration dynamics. The results showed that the four kinds of litter showed the decrease of DOC concentration and the increase of TDN concentration. Soil fauna significantly reduced the DOC content of litter and increased the TDN content, and this phenomenon was the most obvious in the litter of Pinus massoniana and Cryptomeria fortunei. The effect of soil fauna on the DOC content in litter leaves was more evident in the leaf-decay period, while the effect on TDN content was more pronounced at the late autumn leaves. These results indicated that soil fauna significantly affected the dynamics of soluble carbon and nitrogen during litter decomposition, which provided a theoretical basis for understanding the phenomenon of nitrogen retention during litter decomposition. At the same time, soil fauna reduced the soluble nitrogen concentration of litter in the growing season, which may be beneficial to meet the nutrient demand of plants in the growing season.