Abstract Soil organic matter (SOM) accumulation is different in certain soil groups with differences in parent material, degree of weathering and mineral composition. These differences are modulated by climatic factors, but also by pedogenesis, in particular by the formation of reactive mineral surfaces, by soil aggregation, as well as by translocation processes such as eluviation and illuviation and different types of turbation. However, there is still a lack of conceptualization of how such processes and thus important Reference Soil Groups influence the composition and properties of OM. Here we summarize the basic processes of OM storage as they differ from soil group to soil group, in order to present a first overview of the processes of OM formation in the different terrestrial soils of the world. We distinguish between soils of different climatic zones, i.e. Cryosols in permafrost regions, soils of limited development (Cambisols), Podzols, Phaeozems, Chernozems, Kastanozems, and Luvisols in temperate climate zones, as well as Acrisols, Ferralsols, Plinthosols and Nitisols in the subtropics and tropics. We also include soils derived from a specific parent material (Andosols, Vertisols), as well as Anthrosols (paddy soils, Terra Preta, plaggen soils) as examples for human-made SOM accumulations. The compilation of the literature shows that research on OM is clearly focused on specific Reference Soil Groups in temperate climate zones and some man-made soils, while other soils such as Nitisols and Acrisols are clearly underrepresented. The contribution of the different soil groups to global organic carbon (OC) stocks varies, with large amounts of OC found for the first metre in Cryosols, Cambisols, and Podzols, due to the large land area they cover, followed by Acrisols and Ferralsols. In part, these differences can be attributed to differences in the formation of SOM, which we ascribe to three main mechanisms. We emphasize that in all major Reference Soil Groups, both the mechanism of sorptive conservation as well as the protection within the aggregates contribute to the storage of OM. However, the reactant partners and aggregate forming agents and therewith the intensity of these stabilisation processes vary among the Reference Soil Groups. As a result, there are differences in the SOM composition in the topsoil. Within the entire soil profile, however, pedogenic processes lead as third mechanism to soil-group-specific accrual of SOM in the subsoil, e.g. by means of illuviation, by cryo-/bio-, and peloturbation, as well as by management. We conclude that the specific pedogenic environment must be considered in the assessment of global SOM storage potentials and thus also in future global C models.

中文翻译：

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主要成土土壤群的土壤有机质

摘要 土壤有机质（SOM）积累在某些土壤组中存在差异，其母质、风化程度和矿物组成存在差异。这些差异受气候因素的调节，但也受成土作用的调节，特别是受活性矿物表面的形成、土壤聚集以及易位过程（如淋溶和冲积和不同类型的扰动）的调节。然而，对于这些过程以及重要的参考土壤组如何影响 OM 的组成和特性，仍然缺乏概念化。在这里，我们总结了 OM 存储的基本过程，因为它们因土壤组而异，以便首先概述世界不同陆地土壤中 OM 的形成过程。我们区分了不同气候带的土壤，即永久冻土区的冻土、发育受限的土壤 (Cambisols)、温带气候区的灰化土、风化土、黑钙土、Kastanozems 和 Luvisols，以及温带地区的 Acrisols、Ferralsols、Plinthosols 和 Nitisols。亚热带和热带。我们还包括源自特定母体材料（Andosols、Vertisols）的土壤，以及 Anthrosols（稻田土壤、Terra Preta、plaggen 土壤）作为人造 SOM 积累的示例。文献汇编表明，对 OM 的研究显然侧重于温带气候区和一些人造土壤中的特定参考土壤组，而其他土壤（如 Nitisols 和 Acrisols）的代表性明显不足。不同土壤组对全球有机碳 (OC) 库的贡献各不相同，在 Cryosols、Cambisols 和 Podzols 的第一米发现大量 OC，因为它们覆盖的土地面积很大，其次是 Acrisols 和 Ferralsols。在某种程度上，这些差异可归因于 SOM 形成的差异，我们将其归因于三种主要机制。我们强调，在所有主要参考土壤组中，吸附保存机制和聚集体内的保护都有助于 OM 的储存。然而，反应物伙伴和聚集体形成剂以及这些稳定过程的强度在参考土壤组之间变化。因此，表土中的 SOM 组成存在差异。然而，在整个土壤剖面内，土壤生成过程作为第三种机制导致底土中 SOM 特定于土壤组的积累，例如 通过照明、低温/生物和水流扰动以及管理。我们得出的结论是，在评估全球 SOM 储存潜力时必须考虑特定的成土环境，因此在未来的全球 C 模型中也必须考虑。