Data from: Higher fungal diversity is correlated with lower CO2 emissions from dead wood in a natural forest

Wood decomposition releases almost as much CO2 to the atmosphere as does fossil-fuel combustion, so the factors regulating wood decomposition can affect global carbon cycling. We used metabarcoding to estimate the fungal species diversities of naturally colonized decomposing wood in subtropical China and, for the first time, compared them to concurrent measures of CO2 emissions. Wood hosting more diverse fungal communities emitted less CO2, with Shannon diversity explaining 26 to 44% of emissions variation. Community analysis supports a ‘pure diversity’ effect of fungi on decomposition rates and thus suggests that interference competition is an underlying mechanism. Our findings extend the results of published experiments using low-diversity, laboratory-inoculated wood to a high-diversity, natural system. We hypothesize that high levels of saprotrophic fungal biodiversity could be providing globally important ecosystem services by maintaining dead-wood habitats and by slowing the atmospheric contribution of CO2 from the world’s stock of decomposing wood. However, large-scale surveys and controlled experimental tests in natural settings will be needed to test this hypothesis.

木材分解向大气中释放的二氧化碳量几乎与化石燃料燃烧相当，因此调控木材分解的因素可对全球碳循环产生影响。本研究采用元条形码测序（metabarcoding）技术，对中国亚热带地区自然定殖的腐朽木材的真菌物种多样性进行评估，并首次将其与同步测定的二氧化碳排放量进行对比。结果显示，真菌群落多样性更高的木材，其二氧化碳排放量更低，香农多样性指数（Shannon diversity）可解释26%至44%的排放量变异。群落分析证实了真菌对分解速率的‘纯多样性效应’，由此表明干扰竞争是其潜在作用机制。本研究结果将此前采用低多样性实验室接种木材的已发表实验结论，拓展至高多样性自然系统中。我们提出假说：高水平的腐生真菌（saprotrophic fungi）生物多样性，可通过维持枯木生境、减缓全球腐朽木材库向大气排放二氧化碳，从而提供具有全球重要性的生态系统服务。不过，仍需开展大规模野外调查与自然环境中的控制性实验，以验证这一假说。