Detritivore conversion of litter into faeces accelerates organic matter turnover

Abstract

Litter-feeding soil animals play a dominant role on litter decomposition by ingesting large amount of plant litter and returning most of it to the soil as faeces. Despite the prevalence of this pathway, the consequences of this transformation on organic matter physicochemical characteristics and decomposition rates are largely unknown. Here, we assessed these consequences for distinct detritivore species (six species) feeding on contrasted litter quality (six litter species). We did so by collected leaf litter and soil animals from diverse species in Scotland. We then fed all soil animal species with litter from all litter species, separately, in all possible combinations. We collected the 36 resulting faeces type, and the 6 intact litter as controls. We then measured a range of physicochemical characteristics (C:N ratio, tannins concentrations, water-holding capacity, specific area, NMR spectra) for all 42 substrates. We also incubated all substrates for 180 days under controlled conditions and measured their respective rates of C and N loss. All methods associated with the collection of these datasets will be available in the resulting manuscript.