土壤分类研究回顾与中国土壤分类系统的修编

中国在第二次土壤普查（二普）中,由百余名土壤科学家共同制定了中国土壤分类系统,作为二普用规范性文档,二普后作为国标在全国推荐使用。对二普分县调查资料的首次汇总显示,从分县资料提取出的土壤分类名与国家标准发布的分类名存在一定差异。为对与国标不符的土壤类型名进行审核和修编,同时弄清中国现有两套土壤分类系统之间,以及这两套系统与世界土壤资源参比基础（WRB）之间的关联,对土壤分类研究进展及存在问题进行了回顾与分析。本研究显示,土壤发生学是各国进行土壤分类的共同基础,虽然理论基础相同,由于不同国家和地区所处气候带不同,拥有的土壤资源类型和人均资源量不同,经济与科技发展水平不同,采用的分类原则、命名规则、地面调查方法和采样量各有差异,最终形成的分类系统各不相同。受各国语言习惯和已有分类系统影响,也受近年来在土壤调查中对了解成土过程需求在弱化的影响,对各国土壤分类系统的整合进展并不顺利。对不同语言土壤分类系统的比较显示：中国国标分类系统更符合汉语语言特征,特别是高层级分类中的60个土类命名,能较好表达中国主要土壤类型的典型特征,易于专业及非专业人员对土壤类型及成土过程的认知,且推广应用时间已有30多年,在全国影响较大,应继续采用。国标分类系统不便进行国际交流的问题应通过建立其高层级分类,特别是国标中60个土类与世界参比基础的关联加以解决。研究表明,将土壤分类名限定于对成土过程的描述,有利于分类系统的稳定和对主要土壤类型成土过程的认知,在层级结构上对分类系统的不断调整,或将成土过程以外的土壤质量评价引入分类系统,将导致繁冗的土壤分类名,弱化对成土过程认知。由于土壤发生分类信息是进行土壤功能性状调查、评价和分类的重要辅助信息,将土壤分类限定于描述发生分类还有利于将其用于阐明土壤肥力、土壤环境和土壤健康功能性状。根据上述观点,对分县资料中土壤类型名进行了编审,土类按照国标发布的60个土类进行了归并,亚类进行了适度归并,在土属和土种名编审中,则对名称中源于现场调查的土壤分类信息尽量予以保留。     

南极半岛海洋气候区的土壤Ⅳ.分类问题

本文简要论述了早期南极土壤分类研究工作。对在南极海洋性气候区应用《美国土壤系统分类》和《国际土壤分类参比基础》进行土壤分类工作的最新实践进行了阐述和比较;同时,依照《中国土壤系统分类》对本区进行了初步的分类尝试。研究结果显示,南极海洋性气候区的主要土壤分别属于《美国土壤系统分类》冻土纲下的各级单元。比较而言,其他两个分类系统在本区的应用相对困难。     

Classification of Urban and Industrial Soils in the World Reference Base for Soil Resources (5 pp)

Background, Aim and Scope   Historically, built areas were ignored in soil mapping and in studies of soil formation and behaviour. It is now recognized that these areas, and therefore their soils, are of prime importance to human populations. Another trend is the large increase in reclaimed lands and new uses for old industrial areas. In several countries there are active projects to map such areas, either with locally-developed classification systems or ad-hoc names. Soil classification gives unique and reproducible names to soil individuals, thereby facilitating correlation of soil studies; this should be possible also for urban soils. The World Reference Base for Soil Resources (WRB) is the soil classification system endorsed by the International Union of Soil Science (IUSS). The 2006 edition has important enhancements which allow urban and industrial soils to be described and mapped, most notably a new reference group, the Technosols. Main Features   Urban soils are first defined, followed by the philosophical basis of soil classification in general and the WRB in particular. WRB 2006 added a new Technosols reference soil group for soils whose properties and function are dominated by technical human activity as evidenced by either a substantial presence of artefacts, or a impermeable constructed geomembrane, or technic hard rock. Technosols are one of Ekranic, Linic, Urbic, Spolic or Garbic; further qualifiers are added to show intergrades to other groups as well as specific soil properties. Soils from fill are recognized as Transportic Regosols or Arenosols. Toxic soils are specifically recognized by a qualifier. Results   - Discussion   The limit between Technosols and other groups may be difficult to determine, because of the requirement that the technic nature dominate any subsequent pedogenesis. Conclusions   - Perspectives   The WRB should certainly be used in all urban soil studies to facilitate communication and correlation of results. In the period leading up to the next revision in 2010, the quantitative results from urban soil studies should be used to refine class definitions.     

Issues related to classification of garden soils from the urban area of Toruń, Poland

ABSTRACT

Nowadays, the city area of Toruń is dominated by anthropogenic and technogenic soils – developed by humans or significantly altered, mainly disturbed in terms of morphology and chemical and physical properties. This study is a continuation of research on the soil cover of the city. The aim of the presented study is to assess extent of garden soils in the city and characterize its properties on the base of five soil profiles in four exemplary gardens in Toruń and evaluate if they meet the classification criteria for Hortic Anthrosols according to World Reference Base (WRB) for Soil Resources. Within the administrative boundaries of the city, 66 allotment gardens are located which totally cover an area of more than 300 ha. They occupy 3% of the city area. None of the studied mineral surface horizons meets the criteria for hortic horizon according to WRB 2015, due to too low phosphorus content. Other hortic criteria were fulfilled. The research on classification issues of garden soils should be continued on larger scale to evaluate if WRB criteria are not too strict taking into account the features of most typical, few decade-old garden soils.     

Soil system and pedogenic processes: Self-organization, time scales, and environmental significance

The essence of pedogenesis, as a synergetic process, consists in generation, selection, accumulation and differentiation of the solids produced in the course of bio-abiotic processes functioning within a soil body. Soil formation in the broad sense is the result of synergetic processes of self-organization of an in situ soil system during its functioning in time and space. Soil formation, sensu stricto, is the transformation of the solid-phase lithomatrix (parent material) of the soil system into the pedomatrix (soil body, soil mantle). Pedogenesis is perceived as an integration of specific pedogenic processes (SPP); each of them characterized by a definite set of solid-phase pedogenic features. Each soil body is formed by a combination of some SPP. The whole set of SPP may be grouped in accordance with their essence, characteristic times (rates) and reversibility-irreversibility. In terms of characteristic times (rates) they may be arranged in three main groups: rapid (10^1–2 years), medium-rate (10^3–4 years), and slow (10^5–6 years). Soil system functioning and soil formation are intimately linked but fundamentally different processes: the former is infinite in time, if not interrupted by external factors; the latter, as any self-organization process, is finite in time and tends to reach a steady state. The theoretical grouping of the pedogenic processes according to their essence and self-termination or quasi-equilibrium is proposed. All the diagnostic soil horizons (as defined in WRB) are perceived as more or less stable and “mature” degrees of soil self-development. They may be separated into favorable and unfavorable with respect to their suitability for biota. Favorable conditions are generally common in 12 out of 39 diagnostic horizons and properties (32%). They are mainly influenced by biotic fluxes and cycles, which are comparable to, or exceed, abiotic fluxes and cycles in their strength and capacity. In this case, biota transforms and improves the environment rather than adapts to it. Unfavorable conditions are more common in 27 out of 39 diagnostic horizons and properties (68%). They are influenced by the mutual action both of biotic and abiotic fluxes and cycles. In this case, biota adapts to the environment rather than improves it.     

WRB-Excursion on Technosols and Stagnosols through Germany in August 2007

About 40 anthropogenic soils and soils altered by stagnant water were presented during an excursion through Germany. The discussion during this tour aimed mainly at the definitions of the WRB (World Reference Base for Soil Resources) soil groups Technosols and Stagnosols.