Climate change alters frequencies and intensities of soil drying-rewetting and freezing-thawing cycles. These fluctuations affect soil water availability, a crucial driver of soil microbial activity. While these fluctuations are leaving imprints on soil microbiome structures, the question remains if the legacy of one type of weather fluctuation (e.g., drying-rewetting) affects the community response to the other (e.g., freezing-thawing). As both phenomenons give similar water availability fluctuations, we hypothesized that freezing-thawing and drying-rewetting cycles have similar effects on the soil microbiome. We tested this hypothesis by establishing targeted microcosm experiments. We created a legacy by exposing soil samples to a freezing-thawing or drying-rewetting cycle (phase 1), followed by an additional drying-rewetting or freezing-thawing cycle (phase 2). We measured soil respiration and analyzed soil microbiome structures. Across experiments, larger CO₂ pulses and changes in microbiome structures were observed after rewetting than thawing. Drying-rewetting legacy affected the microbiome and CO₂ emissions upon the following freezing-thawing cycle. Conversely, freezing-thawing legacy did not affect the microbial response to the drying-rewetting cycle. Our results suggest that drying-rewetting cycles have stronger effects on soil microbial communities and CO₂ production than freezing-thawing cycles and that this pattern is mediated by sustained changes in soil microbiome structures.

气候变化改变了土壤干燥-再湿润和冻融循环的频率和强度。这些波动会影响土壤水分的有效性，这是土壤微生物活动的关键驱动力。虽然这些波动在土壤微生物组结构上留下了印记，但问题仍然存在，即一种天气波动（例如，干燥-再湿润）的遗留影响是否会影响群落对另一种（例如，冻融）的反应。由于这两种现象都会产生相似的可用水波动，我们假设冻融和干燥-再润湿循环对土壤微生物组具有相似的影响。我们通过建立有针对性的微观世界实验来检验这一假设。我们通过将土壤样本暴露在冻融或干燥再润湿循环（第 1 阶段）中创造了一项遗产，随后是额外的干燥-再润湿或冷冻-解冻循环（第 2 阶段）。我们测量了土壤呼吸并分析了土壤微生物组结构。在整个实验中，较大的 CO₂脉冲和微生物组结构的变化在再润湿后比解冻后观察到。在接下来的冻融循环中，干燥-再润湿遗留影响微生物组和 CO _2排放。相反，冻融遗留不影响微生物对干燥-​​再润湿循环的反应。我们的结果表明，与冻融循环相比，干燥-再润湿循环对土壤微生物群落和 CO _{2产生的影响更强，并且这种模式是由土壤微生物组结构的持续变化介导的。}