Mycorrhizas transfer carbon in a mature mixed forest.

Mycorrhizal fungi transfer nutrients to plants in exchange for photosynthates. Plants allocate up to 20% of their carbon to mycorrhizal structures, mycelium and fruit bodies of their fungal partners. Individuals of mycorrhizal fungi may encompass hundreds of square metres of soil and defragmented litter, linking multiple plant individuals of different species and size (Figure 1).

Litter decay controlled by temperature, not soil properties, affecting future soil carbon.

Widespread global changes, including rising atmospheric CO concentrations, climate warming and loss of biodiversity, are predicted for this century; all of these will affect terrestrial ecosystem processes like plant litter decomposition. Conversely, increased plant litter decomposition can have potential carbon-cycle feedbacks on atmospheric CO levels, climate warming and biodiversity. But predicting litter decomposition is difficult because of many interacting factors related to the chemical, physical and biological properties of soil, as well as to climate and agricultural management practices.