SGER: Amount, Rate and C-isotope value of Soil Organic Matter Production by Armadillidium vulgare

大型土壤动物的取食活动对土壤有机质的化学和物理转化具有重要影响。在没有蚯蚓的中生和旱生生境中(例如，美国西南部的部分地区)，土壤等足目动物可能是主要的有害动物。因此，土壤等足目可能在这些地区的有机质加工、碳和氮循环以及土壤发育中发挥关键作用。这项研究是关于陆地等足类通过取食和排泄对土壤剖面有机层的影响的初步工作。这项研究将利用自然丰度13C/12C比值来调查土壤等足类利用的有机质的来源和去向。在对常见的陆地等足类动物研究的模式生物--普通青虫的摄食实验中，研究人员将确定土壤有机基质(绿叶、凋落物层和土壤腐殖质)的摄食量和摄食率。他们还将评估在粪便生产过程中有机物质的C：N、%C和*13C组成的变化。这项研究对中生和旱生生境的生态系统过程具有广泛的影响，因为它在全球范围内的分布。

Feeding activities of soil macrofauna exert critical influence upon the chemical and physical transformation of soil organic matter. In mesic and xeric habitats where earthworms are absent (e.g., parts of the Southwestern U.S.), soil isopods can be the primary detritivores. It is therefore likely that soil isopods play a pivotal role in organic matter processing, carbon and nitrogen cycling, and soil development in these regions. This research represents preliminary work on the influence of terrestrial isopods on the organic horizons of the soil profile through feeding and excretion. The research will utilize natural abundance 13C/12C ratios to investigate the source and fate of organic matter utilized by soil isopods. In feeding experiments to Armadillidium vulgare, a model organism for terrestrial isopod research due to its ubiquity, the investigators will determine feeding amount and rate across a gradient of soil organic substrates: green leaves, litter layer, and soil humus. They will also assess changes in C:N, %C and *13C composition of organic matter during feces production. The research has widespread implications to ecosystem processes in mesic and xeric habitats, due to the global distribution of Armadillidium vulgare.