soil contamination

Alfisols form under forest vegetation where the parent material has undergone significant weathering. These soils are quite widespread in their distribution and are found from southern Florida to northern Minnesota. The most distinguishing characteristics of this soil type are the illuviation of clay in the B horizon, moderate to high concentrations of base cations, and light-colored surface horizons. Histosols are organic soils that form in areas of poor drainage. Their profile consists of thick accumulations of organic matter at various stages of decomposition. * Podzol - is a soil commonly found under coniferous forests. Its main identifying traits are a poorly decomposed organic layer, an eluviated A horizon, and a B horizon with illuviated organic matter, aluminum, and iron. The forested regions of southern Ontario and the temperate rainforests of British Columbia normally have podzolic soils. Like the U.S. system, the Canadian System of Soil Classification differentiates soil types on the basis of measured properties of the profile and uses a hierarchical scheme to classify soils from general to specific. The most recent version of the classification system has five categories in its hierarchical structure. From general to specific, the major categories in this system are: orders, great groups, subgroups, families, and series. At its most general level, the Canadian System recognizes nine different soil orders: Mollisols are soils common to grassland environments. In the United States most of the natural grasslands have been converted into agricultural fields for crop growth. Mollisols have a dark-colored surface horizon, tend to be base rich, and are quite fertile. The dark color of the A horizon is the result of humus enrichment from the decomposition of litterfall. Mollisols found in more arid environments often exhibit calcification. Canada's first independent taxonomic system of soil classification was first introduced in 1955. Prior to 1955, systems of classification used in Canada were strongly based on methods being applied in the United States. However, the U.S. system was based on environmental conditions common to the United States. Canadian soil scientists required a new method of soil classification that focused on pedogenic processes in cool climatic environments. Andisols develop from volcanic parent materials. Volcanic deposits have a unique process of weathering that causes the accumulation of allophane and oxides of iron and aluminum in developing soils.

* Podzol - is a soil commonly found under coniferous forests. Its main identifying traits are a poorly decomposed organic layer, an eluviated A horizon, and a B horizon with illuviated organic matter, aluminum, and iron. The forested regions of southern Ontario and the temperate rainforests of British Columbia normally have podzolic soils. Figure 17: Forested Podzolic Landscape (Ontario). (Source: Soil Landscapes of Canada, Version 2.2, Agriculture and Agri-Food Canada. 1996) Alfisols form under forest vegetation where the parent material has undergone significant weathering. These soils are quite widespread in their distribution and are found from southern Florida to northern Minnesota. The most distinguishing characteristics of this soil type are the illuviation of clay in the B horizon, moderate to high concentrations of base cations, and light-colored surface horizons. Canadian System of Soil Classification