Non-additive effects of leaf litter and insect frass mixture on decomposition processes
Non-additive effects of leaf litter and insect frass mixture on decomposition processes
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DOI：
10.1007/s11284-011-0868-6
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发表时间：
2011
影响因子：
2
通讯作者：
H. Kagata;T. Ohgushi
中科院分区：
文献类型：
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作者：
H. Kagata;T. Ohgushi
尽管越来越多的证据表明，草食昆虫通过粪便排泄对分解和土壤养分动态产生重大影响，但人们对凋落叶和昆虫粪便的混合物如何影响这种生态系统过程仍知之甚少。本研究以柳树（Salix gilgianaSeemen）和草食性昆虫（Parasa consociaWalker）为研究对象，研究了凋落叶和虫草混合对土壤分解和养分有效性的影响。昆虫草的化学特性与凋落叶不同。其中，禾本科的氨氮（NH4+ -N）含量是凋落物的42倍。培养试验表明，草叶对N的分解和固定化比凋落物更快。此外，随凋落物与草叶混合比例的不同，凋落物与草叶混合对NH4+ -N的分解和还原表现出非加性的促进作用。这些结果表明，虽然虫草通常加速分解，但虫草对土壤养分有效性的影响主要取决于凋落物和虫草的相对数量。
Although there is a growing body of evidence that herbivorous insects have a significant impact on decomposition and soil nutrient dynamics through frass excretion, how mixtures of leaf litter and insect frass influence such ecosystem processes remains poorly understood. We examined the effects of mixing of leaf litter and insect frass on decomposition and soil nutrient availability, using a study system consisting of a willow,Salix gilgianaSeemen, and a herbivorous insect,Parasa consociaWalker. The chemical characteristics of insect frass differed from those of leaf litter. In particular, frass had a 42-fold higher level of ammonium–nitrogen (NH4+–N) than litter. Incubation experiments showed that the frass was decomposed and immobilized with respect to N more rapidly than the litter. Furthermore, litter and frass mixtures showed non-additive enhancement of decomposition and reduction of NH4+–N, depending on the litter–frass mixing ratio. These indicate that, while insect frass generally accelerated decomposition, the effect of frass on soil nutrient availability was dependent largely on the relative amounts of litter and frass.