Maynard Daniel S, Crowther Thomas W, Bradford Mark A
School of Forestry and Environmental Studies, Yale University, 370 Prospect St, New Haven, CT, USA.
Department of Ecology & Evolution, University of Chicago, 1101 E 57th Street, Chicago, IL, 60637, USA.
Ecol Lett. 2017 Aug;20(8):1034-1042. doi: 10.1111/ele.12801. Epub 2017 Jul 4.
The efficiency by which fungi decompose organic matter contributes to the amount of carbon that is retained in biomass vs. lost to the atmosphere as respiration. This carbon use efficiency (CUE) is affected by various abiotic conditions, including temperature and nutrient availability. Theoretically, the physiological costs of interspecific interactions should likewise alter CUE, yet the magnitude of these costs is untested. Here we conduct a microcosm experiment to quantify how interactions among wood-decay basidiomycete fungi alter growth, respiration and CUE across a temperature and nitrogen gradient. We show that species interactions induced consistent declines in CUE, regardless of abiotic conditions. Multispecies communities exhibited reductions in CUE of up to 25% relative to individual CUE, with this biotic effect being greater than the observed variation attributable to abiotic conditions. Our results suggest that the extent to which fungal-mediated carbon fluxes respond to environmental change may be influenced strongly by species interactions.
真菌分解有机物的效率决定了碳是保留在生物量中还是通过呼吸作用释放到大气中。这种碳利用效率（CUE）受多种非生物条件影响，包括温度和养分有效性。从理论上讲，种间相互作用的生理成本同样会改变CUE，但这些成本的大小尚未得到验证。在此，我们进行了一项微观实验，以量化木材腐朽担子菌之间的相互作用如何在温度和氮梯度范围内改变生长、呼吸作用和CUE。我们发现，无论非生物条件如何，物种间相互作用都会导致CUE持续下降。多物种群落的CUE相对于单个CUE降低了25%，这种生物效应大于非生物条件导致的观测变化。我们的结果表明，真菌介导的碳通量对环境变化的响应程度可能受到物种间相互作用的强烈影响。
