Journal article
Authors list: Fox, O; Vetter, S; Ekschmitt, K; Wolters, V
Publication year: 2006
Pages: 1353-1363
Journal: Soil Biology and Biochemistry
Volume number: 38
Issue number: 6
ISSN: 0038-0717
DOI Link: https://doi.org/10.1016/j.soilbio.2005.10.014
Publisher: Elsevier
Abstract:
Traditional models of soil organic matter decomposition predict that soil carbon pools with high chemical stability and large physical structure are more resistant against degradation than chemically labile and fine-grained material. We investigated whether soil fauna, by its direct and indirect effects on carbon turnover, would reinforce or counteract this general trend.The effects of four major faunal groups on carbon pools of differing recalcitrance were studied in an extensive microcosm experiment. Ninty-six microcosms were inoculated with nematodes, enchytraeids, collembola, and lumbricids in three densities, including combinations of groups. Bare agricultural soil and soil covered with maize litter were used as substrates. The microcosms were kept under constant conditions at 12 degrees C and 50% water holding capacity for 60 days. At the end of the experiment, soil particles were separated into size classes (< 63 mu m, 63-250 mu m, > 250 mu m) and carbon pools were separated into solubility fractions (K2SO4-SO4-soluble, pyrophosphate-soluble, insoluble), by means of ultrasonic dispersion and subsequent stepwise solubilisation.Both in bare soil and in soil with litter, the carbon pools with the highest chemical stability (insoluble) and the larger particle sizes (> 63 mu m) were degraded more intensively than all other pools in the presence of lumbricids. The pools of intermediate chemical stability (pyrophosphate-soluble) underwent simultaneous degradation and neoformation brought about by different animal groups. The chemically most labile pool (K2SO4-soluble) remained largely unaffected by the fauna. Fixation of carbon in microbial biomass was increased by nematodes in bare soil and by enchytraeids in soil with litter. The results illustrate in detail how, under the influence of soil fauna, soil carbon pools are decomposed in a cascade-like process where carbon is transferred from the stable to the more labile pools, while simultaneously a proportion is fixed in microbial biomass and another part is lost as CO2. Thereby, the relationship between a substrate's persistence and its chemical stability and physical size is substantially modified. We summarize the mechanisms that most likely are responsible for the different effects of the investigated faunal groups.
Citation Styles
Harvard Citation style: Fox, O., Vetter, S., Ekschmitt, K. and Wolters, V. (2006) Soil fauna modifies the recalcitrance-persistence relationship of soil carbon pools, Soil Biology and Biochemistry, 38(6), pp. 1353-1363. https://doi.org/10.1016/j.soilbio.2005.10.014
APA Citation style: Fox, O., Vetter, S., Ekschmitt, K., & Wolters, V. (2006). Soil fauna modifies the recalcitrance-persistence relationship of soil carbon pools. Soil Biology and Biochemistry. 38(6), 1353-1363. https://doi.org/10.1016/j.soilbio.2005.10.014
