Links among warming, carbon and microbial dynamics mediated by soil mineral weathering
Links among warming, carbon and microbial dynamics mediated by soil mineral weathering
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DOI：
10.1038/s41561-018-0168-7
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发表时间：
2018-08-01
影响因子：
18.3
通讯作者：
Boeckx, P.
中科院分区：
文献类型：
--
作者：
Doetterl, S.;Berhe, A. A.;Boeckx, P.
在全球变化的背景下，量化土壤碳动态至关重要，因为土壤在陆地-大气气体交换中发挥着重要作用。我们目前对当前和未来碳动态的理解是有限的，因为我们无法准确地表示跨时间和空间尺度的土壤过程，部分原因是缺乏关于微生物、地球化学和气候控制之间的相对重要性和层次关系的数据。在这里，我们利用对加利福尼亚州默塞德河冲积阶地沉积物中保存的 3000 公里历史土壤年代序列的观测，展示了短期生物反应和长期矿物风化之间的关系如何驱动土壤碳动态。我们通过异养呼吸与微生物活动和群落组成的关系，将异养呼吸的温度敏感性与生物地球化学土壤特性联系起来。我们发现土壤矿物学，特别是矿物反应性和由此产生的养分有效性的变化，通过改变碳输入、碳稳定性、微生物群落组成和细胞外酶活性，影响异养土壤呼吸对变暖的响应。我们证明，土壤基质的生物地球化学变化（而不是短期变暖）控制着微生物群落的组成和养分代谢策略。更具体地说，风化首先增加然后减少养分的可用性和保留，以及土壤稳定碳的潜力。
Quantifying soil carbon dynamics is of utmost relevance in the context of global change because soils play an important role in land-atmosphere gas exchange. Our current understanding of both present and future carbon dynamics is limited because we fail to accurately represent soil processes across temporal and spatial scales, partly because of the paucity of data on the relative importance and hierarchical relationships between microbial, geochemical and climatic controls. Here, using observations from a 3,000-kyr-old soil chronosequence preserved in alluvial terrace deposits of the Merced River, California, we show how soil carbon dynamics are driven by the relationship between short-term biotic responses and long-term mineral weathering. We link temperature sensitivity of heterotrophic respiration to biogeochemical soil properties through their relationship with microbial activity and community composition. We found that soil mineralogy, and in particular changes in mineral reactivity and resulting nutrient availability, impacts the response of heterotrophic soil respiration to warming by altering carbon inputs, carbon stabilization, microbial community composition and extracellular enzyme activity. We demonstrate that biogeochemical alteration of the soil matrix (and not short-term warming) controls the composition of microbial communities and strategies to metabolize nutrients. More specifically, weathering first increases and then reduces nutrient availability and retention, as well as the potential of soils to stabilize carbon.