Insight into the indirect function of isopods in litter decomposition in mixed subtropical forests in China
Insight into the indirect function of isopods in litter decomposition in mixed subtropical forests in China
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DOI：
10.1016/j.apsoil.2014.10.015
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发表时间：
2015-02-01
影响因子：
4.8
通讯作者：
Tian, Xingjun
中科院分区：
文献类型：
--
作者：
Jia, Yanyan;Lv, Yanna;Tian, Xingjun
地上的消费者可以通过将垃圾转化为粪便来塑造森林棕色食物网的地下过程。木虱是重要的地上消费群体之一，推动地下土壤的动态。虽然有大量关于凋落物分解的数据，但木虱（不同质量的粪便）对凋落物分解的间接影响需要进一步探讨。在这项研究中，我们评估的影响等足类动物（Armadillidium vulgare）及其副产品（三个对比品质的粪便）的分解阔叶和针叶凋落物通过土壤培养。通过6个月的室内培养试验，测定了不同等足类动物副产物处理的阔叶凋落物质量损失、土壤微生物生物量和土壤胞外酶活性，结果表明，动物粪便的间接作用对阔叶凋落物的分解没有显著促进作用。然而，高品质的豆类凋落物喂养的等足类动物的粪便显着增加针叶凋落物的分解。等足类动物粪便对土壤微生物活性的影响显著：阔叶林和针叶林土壤中大部分微生物生物量和胞外酶活性较无粪便处理显著增加;针叶林中优质粪便加强了凋落物质量损失与过氧化物酶和酚氧化酶的相关性。结果表明，具有较高浓度的氮和不稳定碳的粪便可以介导木质素和酚类化合物等难降解物质的分解，这可能与大型底栖动物丰度高的生态系统中的凋落物分解过程高度相关。这项研究推断，等足类动物（粪便）对凋落物分解的间接影响取决于它们所消耗的凋落物的质量和分解的凋落物的类型。等足类动物通过将高质量的凋落物转化为粪便，间接加速了养分贫乏的凋落物分解过程。因此，间接减轻了混交林中枯枝落叶层顽固性对微生物分解的负面影响。(C)2014爱思唯尔有限公司版权所有。
Aboveground consumers can shape belowground processes in brown-food webs of forests by converting litter into faeces. Woodlice are one of the important aboveground consumer groups driving the dynamics of belowground soil. Although considerable data on litter decomposition exists, the indirect effects of woodlice (different qualities of faeces) on litter decomposition need to be explored further. In this study, we assessed the influence of isopods (Armadillidium vulgare) and its by-products (three contrasting qualities of faeces) on the decomposition of broad-leaf and needle litter via soil incubation. Litter mass loss, soil microbial biomass and soil extracellular enzyme activities treated with different isopod byproducts were determined in six-month laboratory incubations.The results showed that after incubation, the indirect effect of fauna (faeces) did not significantly increase broad-leaf litter decomposition. However, faeces of isopods fed on high-quality legume litter significantly increased needle litter decomposition. The effects of isopod faeces on microbial activities were significant: most of the soil microbial biomass and extracellular enzyme activities increased significantly compared with non-faeces treatments in the soil of broad-leaved and coniferous forests; and high-quality faeces strengthened the correlation of litter mass loss with peroxidase and phenol oxidase in coniferous forest. The result suggests that faeces with higher concentrations of nitrogen and labile carbon can mediate the decomposition of refractory materials like lignin and phenolic compounds, which might be highly relevant for the litter decomposition process in ecosystems with high macrofauna abundance. This study infers that the indirect effect of isopods (faeces) on litter decomposition depends on the quality of the litter they consumed and the type of decomposing litter. Isopods indirectly accelerate the nutrient-poor litter decomposition process by converting high-quality litter into faeces. As such, the negative effects of litter recalcitrance on microbial decomposition in mixed forests are indirectly alleviated. (C) 2014 Elsevier B.V. All rights reserved.