Fungal interactions reduce carbon use efficiency

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 env...

真菌分解有机质的效率，决定了生物质中留存的碳与通过呼吸作用散失至大气的碳的比例。碳利用效率（carbon use efficiency, CUE）受温度、养分可利用性等多种非生物条件调控。理论上，种间相互作用带来的生理代价同样会改变CUE，但此类代价的影响幅度尚未得到实验验证。本研究通过微宇宙实验（microcosm experiment），量化了在温度与氮素梯度下，木腐担子菌（wood-decay basidiomycete）之间的相互作用如何改变真菌的生长、呼吸作用及CUE。研究结果显示，无论非生物条件如何，物种间的相互作用均会导致CUE出现一致的下降。相较于单一菌株的CUE，多物种群落的CUE最高可降低25%，且该生物效应的影响幅度大于非生物条件带来的观测变异。本研究结果表明，真菌介导的碳通量对环境的响应程度（原文后续内容截断为env...）。