Soil bacteria are largely missing from future biodiversity assessments hindering comprehensive forecasts of ecosystem changes. Soil bacterial communities are expected to be more strongly driven by pH and less by other edaphic and climatic factors. Thus, alkalinisation or acidification along with climate change may influence soil bacteria, with subsequent influences for example on nutrient cycling and vegetation. Future forecasts of soil bacteria are therefore needed. We applied species distribution modelling (SDM) to quantify the roles of environmental factors in governing spatial abundance distribution of soil bacterial OTUs and to predict how future changes in these factors may change bacterial communities in a temperate mountain area. Models indicated that factors related to soil (especially pH), climate and/or topography explain and predict part of the abundance distribution of most OTUs. This supports the expectations that microorganisms have specific environmental requirements (i.e., niches/envelopes) and that they should accordingly respond to environmental changes. Our predictions indicate a stronger role of pH over other predictors (e.g. climate) in governing distributions of bacteria, yet the predicted future changes in bacteria communities are smaller than their current variation across space. The extent of bacterial community change predictions varies as a function of elevation, but in general, deviations from neutral soil pH are expected to decrease abundances and diversity of bacteria. Our findings highlight the need to account for edaphic changes, along with climate changes, in future forecasts of soil bacteria.

未来的生物多样性评估中很大程度上缺少土壤细菌，这阻碍了对生态系统变化的全面预测。预计土壤细菌群落受 pH 值的影响更大，而受其他土壤和气候因素的影响较小。因此，碱化或酸化以及气候变化可能会影响土壤细菌，进而影响例如养分循环和植被。因此需要对土壤细菌的未来预测。我们应用物种分布模型 (SDM) 来量化环境因素在控制土壤细菌 OTU 空间丰度分布中的作用，并预测这些因素的未来变化可能如何改变温带山区的细菌群落。模型表明，与土壤有关的因素（尤其是 pH 值），气候和/或地形解释和预测大多数 OTU 的部分丰度分布。这支持了微生物具有特定环境要求（即生态位/外壳）的期望，并且它们应该相应地响应环境变化。我们的预测表明 pH 值在控制细菌分布方面的作用比其他预测因子（例如气候）更强，但预测的细菌群落未来变化小于它们当前在空间中的变化。细菌群落变化预测的程度随着海拔的变化而变化，但总的来说，中性土壤 pH 值的偏差预计会降低细菌的丰度和多样性。我们的研究结果强调了在未来对土壤细菌的预测中，需要考虑土壤变化以及气候变化。