Work

Soil animals influence microbial abundance, but not plant–microbial competition for soil organic nitrogen

Year: 2004

Type: article

Abstract: Summary In a microcosm experiment we examined the effects of individual species of microarthropods, and variations in microarthropod diversity of up to eight species, on soil microbial properties and the short‐term partitioning of a dual‐labelled organic nitrogen source (glycine‐2‐13C‐15N) between a grassland plant,Agrostis capillaris, and the soil microbial biomass, to determine how soil fauna and their diversity influence plant–microbial competition for organic N. We hypothesized that variations in the diversity of animals would influence the partitioning of15N inputs between plants and the microbial biomass, due to the effect of animal grazing on the microbial biomass, and hence its ability to sequester N. Certain individual species of Collembola influenced the microbial community of the soil.Folsomia quadrioculatareduced microbial biomass, whereasMesaphorura macrochaetaenhanced arbuscular mycorrhizal (AM) colonization ofA. capillarisroots. Effects of increasing species richness of microarthropods on microbial biomass and AM colonization were detected, but these effects could be interpreted in relation to the presence or absence of individual species. Microbial uptake of added15N was not affected by the presence of any of the individual species of animal in the monoculture treatments. Similarly, increasing diversity of microarthropods had no detectable effect on microbial15N. Root and shoot uptake of15N was also largely unaffected by both single species and variations in diversity of microarthropods. However, one collembolan species,Ceratophysella denticulata, reduced root15N capture when present in monoculture. We did not detect13C in plant tissue under any experimental treatments, indicating that all N was taken up by plants after mineralization. Our data suggest that, while single species and variations in diversity of microarthropods influence microbial abundance in soil, there is no effect on microbial or plant uptake of N. Overall, these data provide little support for the notion that microbial‐feeding soil animals are regulators of microbial–plant competition for N.

Source: Functional Ecology

DOI: 10.1111/j.0269-8463.2004.00894.x

Authors: L. COLE, P. L. STADDON, D. SLEEP, R. D. BARDGETT

Institutions: UK Centre for Ecology & Hydrology, Lancaster University, Natural Environment Research Council

Language: English

Topic: Soil Carbon and Nitrogen Dynamics

Subfield: Soil Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Life on land

Open Access status: bronze

Funders: European Commission, Sveriges Lantbruksuniversitet, Natural Environment Research Council, Centre for Ecology and Hydrology