Abstract:
:Fungi play crucial roles in the biogeochemistry of terrestrial ecosystems, most notably as saprophytes decomposing organic matter and as mycorrhizal fungi enhancing plant nutrient uptake. However, a recurrent problem in fungal ecology is to establish the trophic status of species in the field. Our interpretations and conclusions are too often based on extrapolations from laboratory microcosm experiments or on anecdotal field evidence. Here, we used natural variations in stable carbon isotope ratios (delta(13)C) as an approach to distinguish between fungal decomposers and symbiotic mycorrhizal fungal species in the rich sporocarp flora (our sample contains 135 species) of temperate forests. We also demonstrated that host-specific mycorrhizal fungi that receive C from overstorey or understorey tree species differ in their delta(13)C. The many promiscuous mycorrhizal fungi, associated with and connecting several tree hosts, were calculated to receive 57-100% of their C from overstorey trees. Thus, overstorey trees also support, partly or wholly, the nutrient-absorbing mycelia of their alleged competitors, the understorey trees.
journal_name
Proc Natl Acad Sci U S Aauthors
Högberg P,Plamboeck AH,Taylor AF,Fransson PMdoi
10.1073/pnas.96.15.8534keywords:
subject
Has Abstractpub_date
1999-07-20 00:00:00pages
8534-9issue
15eissn
0027-8424issn
1091-6490journal_volume
96pub_type
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