Role of Soils Both the physical and chemical structure of soil influences the ways that plants obtain minerals from it. Soil from an ecological standpoint is that part of the Earth's surface in which plants grow, including —the thin layer on the surface of rocks penetrated by mosses, as well as the rich, black loam underlying Iowa cornfields. Soils are dynamic and ever-changing. They have a structure that both influences, and in turn is influenced by, the plants that they support. The weathering of rocks over time produces the soils from which plants extract water and all but one of the nutrients they need—carbon being the sole exception. Soils, in addition, provide anchorage for plant roots and thus a means of support for the aerial shoots. Air in the pore spaces of soils provides roots with oxygen for respiration and is a depository for the carbon dioxide released in the process. Though soils change constantly as
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This note was uploaded on 11/14/2011 for the course BIO 1421 taught by Professor Farr during the Fall '08 term at Texas State.