The spatial and temporal linkages between turnover of soil microbial communities and their associated functions remain largely unexplored in terrestrial ecosystems. Yet defining these relationships and how they vary across ecosystems and microbial lineages is key to incorporating microbial communities into ecological forecasts and ecosystem models. To define linkages between turnover of soil bacterial and fungal communities and their function we sampled fungal and bacterial composition, abundance, and enzyme activities across a 3-ha area of wet tropical primary forest over two years. We show that fungal and bacterial communities both exhibited temporal turnover, but turnover of both groups was much lower than in temperate ecosystems. Turnover over time was driven by gain and loss of microbial taxa and not changes in abundance of individual species present in multiple samples. Only fungi varied over space with idiosyncratic variation that did not increase linearly with distance among sampling locations. Only phosphorus-acquiring enzyme activities were linked to shifts in septate, decomposer fungal abundance; no enzymes were affected by composition or diversity of fungi or bacteria. While temporal and spatial variation in composition was appreciable, because turnover of microbial communities did not alter the functional repertoire of decomposing enzymes, functional redundancy among taxa may be high in this ecosystem. Slow temporal turnover of tropical soil microbial communities and large functional redundancy suggests that shifts in abundance of particular functional groups may more accurately capture ecosystem function than composition in these heterogeneous ecosystems.

中文翻译：

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土壤微生物群落的时空更新与原始热带森林的功能无关

在陆地生态系统中，土壤微生物群落的更新与其相关功能之间的空间和时间联系在很大程度上仍未得到探索。然而，定义这些关系以及它们如何在生态系统和微生物谱系中变化是将微生物群落纳入生态预测和生态系统模型的关键。为了确定土壤细菌和真菌群落的周转与其功能之间的联系，我们在两年内对 3 公顷潮湿热带原始森林区域的真菌和细菌组成、丰度和酶活性进行了采样。我们表明真菌和细菌群落都表现出时间周转，但两组的周转率远低于温带生态系统。随着时间的推移，周转率是由微生物类群的增加和减少驱动的，而不是多个样本中存在的单个物种丰度的变化。只有真菌在空间上随采样位置之间的距离不随距离线性增加的特殊变化而变化。只有获得磷的酶活性与隔膜、分解真菌丰度的变化有关；没有酶受到真菌或细菌的组成或多样性的影响。虽然组成的时间和空间变化是可观的，但由于微生物群落的更替并没有改变分解酶的功能库，因此该生态系统中分类群之间的功能冗余可能很高。