The whiff of decay: Linking volatile production and extracellular enzymes to outcomes of fungal interactions at different temperatures

The terrestrial carbon cycle is largely driven by photosynthetic plants and decomposer organisms that process biomass to CO2. In forest ecosystems, the decomposers are predominantly wood decay fungi, and the response of community structure and activity to increasing global temperatures is likely critical to forest biogeochemical processes. Metabolic products can drive community structure and substrate utilisation, and the role of volatile organic compounds (VOCs), as well as extracellular enzymes, are of particular interest. Pair-wise interactions of a community of basidiomycetes were made under 3 different microclimate conditions that mimic fluctuations in local climate conditions, and the outcome of interactions was assessed in terms of: (1) which fungus won the confrontation or whether it was a draw (deadlock); (2) the production of volatile organic compounds (VOCs) and enzyme activities; and (3) the rate of decomposition. While substrate utilisation and exploitation in terms of decomposition was not affected, community response to changing temperature was underpinned by altered outcomes of interactions and changes to territory occupation, which were reflected by changes in VOC production and extracellular enzyme activity. This study underlines the importance of understanding the impact of community structure on carbon cycling in forest ecosystems under a changing climate. (C) 2019 The Authors. Published by Elsevier Ltd.