Response of soil biogeochemistry to freeze-thaw cycles and implications for the soil respiration-climate feedback: A process-oriented experimental approach

冻融循环是作用于中高纬度土壤的主要气候强迫因素。土壤的冻结和融化影响其物理性质、生物地球化学过程、微生物群落以及碳和养分收支。尽管过去几十年的研究揭示了冻融循环对温室气体排放和土壤化学淋溶的巨大影响，但其潜在的水文、物理、地球化学和微生物机制及其相互作用仍然知之甚少。一个原因是缺乏时间序列数据来捕捉冻融循环期间土壤系统内的相关运输和反应过程。因此，我们目前在预测土壤过程对目前和未来气候变化驱动的冻融事件的频率、幅度和持续时间变化的反应方面的能力受到严重限制。这样做的中心目的是

Freeze-thaw cycles represent a major climate forcing acting on soils at middle and high latitudes. Freezing and thawing of soils affect their physical properties, biogeochemical processes, microbial community, and carbon and nutrient budgets. Although research during the last few decades has revealed the large effects freeze-thaw cycles have on greenhouse gas emissions and chemical leaching from soils, the underlying hydrological, physical, geochemical and microbial mechanisms, and their mutual interactions, remain poorly understood. One reason is the paucity of time-series data that capture the relevant transport and reaction processes within the soil system during freeze-thaw cycles. As a consequence, we are currently seriously limited in our ability to predict the response of soil processes to changes in the frequency, magnitude and duration of freeze-thaw events driven by ongoing and future climate change. The central aim of this