UNI101Y1 Chapter Notes - Chapter 4: Illuvium, Clay Minerals, Humus
16 Feb 2013
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Document Summary
In the mountains of the sw us, changes in plant communities with elevation result in distinct patterns. 19th century cc hhaarrtt mmeerrrriiaamm referred to these distinct belts of veget. as lliiffee zzoonneess. Climate affects the distribution of plants and animals indirectly by influencing the development of soil. The characteristics of soil determine its ability to hold water and make minerals available to plants. Hhoorriizzoonnss are the distinct layers of a soil cross section. O: primarily dead organic litter, most soil organisms. A: rich in humus, partly decomposed organic material mixed with mineral soil. E: a region of leaching of minerals from the soil, minerals are dissolved (mobilized) here, plant roots are concentrated here, eluviation refers to the downward movement of dissolved or suspended material within the soil by leaching. B: little organic material, chemical composition resembles underlying rock, clay minerals and oxides of aluminum and iron leached out of e are sometimes deposited here (illuviation)
