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

土壤大型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mesic和干性栖息地（例如，美国西南部的部分地区），土壤等足类动物可能是主要的腐食动物。因此，土壤等足类动物可能在这些地区的有机质加工、碳氮循环和土壤发育中起着关键作用。本研究初步探讨了陆生等足类动物通过摄食和排泄对土壤剖面有机层的影响。本研究将利用自然丰度13C/12C比值来研究土壤等足类动物利用有机质的来源和去向。在对普通犰狳（Armadillidium vulgare）的取食实验中，研究人员将确定不同土壤有机基质（绿叶、凋落物层和土壤腐殖质）的取食量和取食率。他们还将评估粪便产生过程中有机质C:N、%C和*13C组成的变化。由于普通犰狳的全球分布，该研究对中旱生境的生态系统过程具有广泛的意义。

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.