Soil microorganisms shape global element cycles in life and death. Living soil microorganisms are a major engine of terrestrial biogeochemistry, driving the turnover of soil organic matter — Earth’s largest terrestrial carbon pool and the primary source of plant nutrients. Their metabolic functions are influenced by ecological interactions with other soil microbial populations, soil fauna and plants, and the surrounding soil environment. Remnants of dead microbial cells serve as fuel for these biogeochemical engines because their chemical constituents persist as soil organic matter. This non-living microbial biomass accretes over time in soil, forming one of the largest pools of organic matter on the planet. In this Review, we discuss how the biogeochemical cycling of organic matter depends on both living and dead soil microorganisms, their functional traits, and their interactions with the soil matrix and other organisms. With recent omics advances, many of the traits that frame microbial population dynamics and their ecophysiological adaptations can be deciphered directly from assembled genomes or patterns of gene or protein expression. Thus, it is now possible to leverage a trait-based understanding of microbial life and death within improved biogeochemical models and to better predict ecosystem functioning under new climate regimes.

土壤微生物塑造了生死攸关的全球元素循环。活的土壤微生物是陆地生物地球化学的主要引擎，推动土壤有机质的周转——地球上最大的陆地碳库和植物养分的主要来源。它们的代谢功能受到与其他土壤微生物种群、土壤动物和植物以及周围土壤环境的生态相互作用的影响。死微生物细胞的残余物可作为这些生物地球化学引擎的燃料，因为它们的化学成分会作为土壤有机物存在。随着时间的推移，这种无生命的微生物生物量会在土壤中累积，形成地球上最大的有机物质池之一。在这篇综述中，我们讨论了有机质的生物地球化学循环如何依赖于活的和死的土壤微生物，它们的功能特性，以及它们与土壤基质和其他生物体的相互作用。随着最近组学的进步，许多构成微生物种群动态及其生态生理学适应性的特征可以直接从组装的基因组或基因或蛋白质表达模式中破译。因此，现在可以在改进的生物地球化学模型中利用基于特征的对微生物生死的理解，并更好地预测新气候条件下的生态系统功能。