Proposed Changes to Soil Taxonomy to Incorporate Human-Altered and Human-Transported Soils.

Soil Taxonomy contains several existing taxa and definitions of diagnostic horizons associated with intentional human activity. Many of the original concepts and diagnostics originated in parts of the world that had been under agricultural use far longer than in the United States. In 1995, a committee (ICOMANTH) was formed to study the addition of what were called anthropogenic soils to Soil Taxonomy. ICOMANTH distributed seven letters internationally and held an international tour. In 1995, a soil survey of New York City was used to test concepts, inventory the type of soils in humid urban areas, gather feedback from soil survey users, and determine the level that new taxa should be introduced. Almost 30 new soil series were proposed. In 2009, an international conference for Soils of Urban, Industrial, Traffic, Mining, and Military Areas was held in New York City. ICOMANTH began adding conventions to the National Cooperative Soil Survey system for describing what are now called human-altered and human-transported (HAHT) soils. Feedback was positive. A new layer, features and materials are proposed. The most efficient level to recognize HAHT soils is at the subgroup level and below, allowing preservation of existing series and maps. More specific identity will be possible for urban and mine soils. Mine soils and urban soils that are all Typic Udorthents would be classed in more specific taxa, with a new family class to indicate unusual properties and materials in the control section. Soils with 50 cm or more of intentional alteration or transportation evidence (presence of new diagnostic materials) would use the new family class. Other soils with irregular decrease in organic carbon and over-thickened surface horizons through natural transportation processes will be classified with HAHT taxa. Anthropic epipedons are more clearly defined, and all epipedons other than anthropic and plaggen will exclude HAHT materials. Detailed proposals will be discussed.