气候变化与土壤侵蚀相互作用研究进展

气候变化和土壤侵蚀是当前全球变化研究重点关注的两个自然过程，二者之间的相互作用是地表过程的重要研究内容之一。本文从土壤侵蚀对气候变化的响应、碳循环过程对土壤侵蚀的反馈两个方面综述了气候变化与土壤侵蚀相互作用研究进展。分析认为：理想的地质载体是深刻理解地质历史时期土壤侵蚀对气候变化响应特征的关键；土壤侵蚀预测模型的适用条件和范围以及降雨侵蚀力估算方法缺乏标准化是造成土壤侵蚀量估算结果存在差异的主要因素；侵蚀作用下土壤有机碳矿化的生物学过程与机制是科学评估土壤侵蚀是碳源或碳汇的关键环节。建议未来在以下三个方向开展工作：（1）以湖泊沉积物为地质载体来研究历史时期气候变化与土壤侵蚀有着巨大发展和应用潜力，建议利用AMS¹⁴C、¹³⁷Cs和²¹⁰Pb等多种定年手段，使用环境指示意义明确的代用指标，建立近千年高分辨率流域气候与侵蚀序列，研究十年至百年尺度气候变化与土壤侵蚀之间的关系；（2）流域版水蚀预报模型（WEPP）可能更适合小流域预测研究，在其实践应用过程中除规范标准小区的坡度和坡长之外，还应通过长期观测和试验来确定不同气候区侵蚀性降雨阙值以便计算降雨侵蚀力；（3）可以尝试采用定量稳定同位素探针技术（qSIP）手段研究微生物对土壤有机碳库的分解和转化的驱动机制，因为qSIP不仅能量化土壤微生物的生长速率，还能同步测定土壤有机碳的矿化速率。

Interaction between climate change and soil erosion: a review

Background, aim, and scope Soil erosion processes accompanied by hydrological and biochemical cycles document the flows and transformations of material, energy, and information from an erosion source to a deposition sink, which are vital for ecological and economic environments in catchments at various scales. Climate (reported hereon are precipitation) is usually considered the main factor controlling soil erosion intensity at the long-historical stage. Therefore, the interaction or relationship between climate change and soil erosion is an important topic in the study of earth surface processes. Here, we summarize the historical background of the study of the interaction between climate change and soil erosion. Major opinions and other recent advances, up to the present, are also reviewed. We then examine recent progress and recommend future research based on current knowledge and technical feasibility. Materials and methods We compiled publications that addressed the interaction between climate change and soil erosion, covering geological archives, model-dependent evaluations, and carbon cycle-soil erosion feedback processes. Results The results are as follows. (1) An ideal geological archive may be the key to understanding the response characteristics of soil erosion to climate change in historical periods. (2) The applicable conditions and scope of soil erosion prediction models and the lack of standardization for rainfall erosivity estimation methods are the main factors that cause differences in soil erosion estimates. (3) Soil erosion plays an important role in shaping modern landforms and physically impacts the carbon process due to soil particle movement. Discussion (1) Lacustrine sediment, as a collector of past climatic and environmental changes, can not only record long-term, continuous, high-resolution, undisturbed information on regional rainfall, vegetation cover, and human disturbances but also provide information about soil erosion processes. Thus, it has a significant advantage in reconstructing soil erosion history. (2) It is critical to choose an independent index for soil calculation models because the factors that affect soil erosion are interrelated and interact with each other. Before applying soil erosion prediction models in practice, however, the observed data must be used to validate the model and calibrate its parameters. In addition, the size of the experimental field plots must parallel those of the unit plot (i.e., with a steepness of 9° and a slope length of 22.13 m) when constructing a steepness or slope length model. Otherwise, the results cannot be compared to other results. (3) Microorganisms have a critical role in controlling terrestrial C fluxes as they promote the release of C to the atmosphere through their catabolic activities. Both the dynamics of soil microorganisms and the mineralization rate of soil organic carbon during the post-erosion period are crucial to accurately define the role of soil erosion as a net carbon sink or atmospheric source. Conclusions (1) These models have the potential to be developed for and applied to lake sediments to create a geological archive, thus enabling the connection between climate change and soil erosion in historical periods to be studied. (2) The soil erosion model is premised upon a top-level design and user-oriented construction, which enable its applicability. Multidisciplinary cooperation, long-term adherence, and new technology updates are also necessary for maintaining the vitality of the models. (3) The biological process and mechanism of soil organic carbon mineralization are the keys to scientifically evaluating soil erosion as a carbon sink or atmospheric source. Recommendations and perspectives Research in the field of climate change and soil erosion interactions is likely to take many new directions in the coming years, refining our understanding of long-standing earth surface process across various fields. Here, we outline a few selected research areas that may provide new insights into both the current situation and future. (1) We recommend using AMS¹⁴C, ¹³⁷Cs, and ²¹⁰Pb to reconstruct the history of soil erosion intensity and climate change during the last millennium as a basis for studying the relationship between soil erosion intensity and climate change on decadal to centennial timescales. In addition, the environmental significance of proxies in lake sediments must be clarified. (2) Long-term high-quality experiments and monitoring provide an important basis for establishing soil erosion models. For the watershed version of the WEPP model, the slope and length of the unit plot should be normalized, and the erosivity of rainfall in different regions should be calculated using the erosive daily rainfall threshold determined via long-term observations and experiments. (3) Quantitative stable isotope probing (qSIP) can be used to study the driving mechanism of microorganism decomposition and transformation into the soil organic carbon pool, because it can not only quantify the growth rate of soil microorganisms, but also simultaneously measure the mineralization rate of soil organic carbon.