Soil
Formation
Soil development involves many physical, chemical and biological factors acting over time on
materials, such as rock, gravel and sand. This process is influenced by
topographic features, like degree of slope, and the presence and actions of
water. Climatic factors, such as precipitation, relative humidity, temperature
and solar radiation, also influence soil formation. For example, cooler
temperatures are less ideal for soil formation because they slow the rate at
which humus accumulates and decomposes. That is why there are thinner topsoils
and fewer available plant nutrients in the soils of the mountains and in
northern Alberta. Soils that receive little moisture, such as sandy areas, can
only support specially adapted plants.
The combined
effects of the various factors that influence soil formation produce many
different types of soils. Soils formed on shale, sandstone, or ground-up rocks
and minerals left by glaciers are called mineral soils. Soils developed in
organic materials like peat are called organic soils.
Two general
processes dominate mineral soil development in Alberta: calcification and acid
leaching.
Department of the Environment. State of the Environment Report, Terrestrial Ecosystems. Edmonton: n.p., 2001. With permission from Alberta Environment.
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