Soil moisture and temperature are incorporated into Soil Taxonomy through the broad classes of moisture and temperature regimes. Although both are important variables in soil formation and land use, soil temperature regime (STR) is typically applied at the family level, whereas soil moisture regime (SMR) is applied at the suborder level. In this paper, we are questioning whether moving SMR to the family level will create a classification system that is more efficient and provide more information to the user at higher categories. The pros and cons of moving ustic, xeric, and udic SMRs from suborder to family category are discussed. To explore this potential change, we used Shannon diversity (ΔH) as an index of the information gain moving from order to suborder when classifying a soil. The analysis indicated a relatively small ΔH for most of the country considering current suborder classes. The proposed group of suborders, characterized by diagnostic horizons instead of SMR, conveyed a considerably larger ΔH supporting a substantial gain in information if the change was incorporated into Soil Taxonomy. The proposed change also has the potential to reduce the number of subgroup taxa by nearly 50%, without losing any of the current information within each taxa. Counterarguments for the change are that SMRs have soil genesis connotations and provide a way to group similar soils on broad-scale maps. A change in the hierarchy of SMRs within Soil Taxonomy could deemphasize the relevance of soil moisture to soil genesis, morphology, and ecology.

中文翻译：

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改变土壤分类学中土壤水分状况的分层位置

土壤水分和温度通过广泛的水分和温度状态被纳入土壤分类法。尽管两者都是土壤形成和土地利用的重要变量，但土壤温度状况 (STR) 通常应用于家庭级别，而土壤湿度状况 (SMR) 应用于亚目级别。在本文中，我们质疑将 SMR 移至家庭级别是否会创建一个更高效的分类系统，并为更高类别的用户提供更多信息。讨论了将 ustic、xeric 和 udic SMR 从亚目转移到家族类别的利弊。为了探索这种潜在的变化，我们使用了香农多样性（ΔH) 作为对土壤进行分类时从阶到亚阶的信息增益指数。分析表明，考虑到当前的亚目类别，该国大部分地区的ΔH相对较小。拟议的亚目组，以诊断范围而不是 SMR 为特征，传达了相当大的ΔH如果将更改纳入土壤分类法，则支持信息的大量获取。拟议的更改还有可能将亚组分类群的数量减少近 50%，而不会丢失每个分类群中的任何当前信息。对这种变化的反驳是，SMR 具有土壤成因的内涵，并提供了一种在大比例尺地图上对相似土壤进行分组的方法。土壤分类学中 SMR 等级的变化可能会削弱土壤水分与土壤发生、形态和生态的相关性。