Natural 13C abundance reveals trophic status of fungi and host-origin of carbon in mycorrhizal fungi in mixed forests

AUTOR(ES)

Högberg, Peter

FONTE

The National Academy of Sciences

RESUMO

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 (δ13C) 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 δ13C. 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.

Documentos Relacionados

• Natural-Abundance 13C Nuclear Magnetic Resonance Spectra of Terpenes and Carotenes*
• Detection of human muscle glycogen by natural abundance 13C NMR.
• Natural-abundance 13C NMR study of glycogen repletion in human liver and muscle.
• Conformational Studies of Various Hemoglobins by Natural-Abundance 13C NMR Spectroscopy
• Cytochrome c. Observation of Numerous Single-Carbon Sites of the Reduced and Oxidized Species by Means of Natural-Abundance 13C Nuclear Magnetic Resonance Spectroscopy