Vertical stratification and trophic interactions among organisms of a soil decomposer food web – a field experiment using 15N as a tool
In this field study, we explored the spatial segregation between the litter- and humus-inhabiting organisms of the detrital food web using 15N-isotope technique. The study was established in 11 × 11 m plots fertilized with 15N-labelled urea. Ten years after urea application, soil samples were taken,...
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Published in | European journal of soil biology Vol. 38; no. 1; pp. 29 - 34 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Paris
Elsevier Masson SAS
2002
Editions scientifiques et médicales Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | In this field study, we explored the spatial segregation between the litter- and humus-inhabiting organisms of the detrital food web using
15N-isotope technique. The study was established in 11 × 11 m plots fertilized with
15N-labelled urea. Ten years after urea application, soil samples were taken, both from the litter layer and the combined F+H layer. The samples were analysed for N content and the proportion of
15N in (i) the residual organic matter in the litter and F+H layer (excluding microbes), (ii) microbial biomass, and (iii) various feeding guilds of soil fauna. The basal resource, soil microbes, and the fauna were more enriched with
15N in the F+H layer than in the litter layer. In the litter layer, the
15N enrichment of the expected food source equalled the one of the consumers, whereas in the F+H layer all trophic groups, except microbes and small microbi-detritivores, showed a significantly lower
15N enrichment than their expected food source. The results indicate that large and mobile humus-inhabiting decomposers exploit the overlying litter layer as a feeding site, whereas the feeding of the more sedentary smaller organisms is restricted to the humus layer. |
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Bibliography: | P34 2003003565 |
ISSN: | 1164-5563 |
DOI: | 10.1016/S1164-5563(01)01119-0 |