Re: pH and oaks
- Subject: Re: pH and oaks
- From: Meum71@aol.com
- Date: Tue, 30 Oct 2001 02:54:11 EST
In a message dated 10/28/2001 2:19:13 PM Central Standard Time, ECPep@aol.com writes:
Do you not think a symbiosis with plant and soil exists?
Plants do play a major role in soil development. In the united states 2 broad classes of soils relatng to plant types exist they fall under "grass land soils" and "forest" soils. Each has a different type of profile mainly do to how they use nutrients and how deep their roots go resulting in the movement of organics. Grass land soils have generally twice the organic content that forest soils do and content is more uniformly distributed to a greater depth. Grass and grass land plants tend to have deep root system since most grass lands form were rainfall is not always adequate for forest ecologies also each type tends to cycle different ions at different rates. Trees have most of their roots with in the first two feet of soil depth and those roots spread out over a great distance from the plants that are not closely fitted together-grass lands have deeper roots within more compact fitting plants this compactness retards water movent into the soil.
Soil formation is a dynamic process that occurs over time-most soils are thousands of years old and most soils that receive enough rain to cause clay formation and clay migration tend to be acid. Plants have less an effect on soil properties than soil does on the types of plants that grow on them. Forest soils tend to have greater movement of clay from the surface to lower levels due to the action of water from rainfall which moves into the soil to a greater depth. While grass land soils show a less degree of clay movement because water is absorbed by plants at the surface or just below (also remember that grass lands tend to receive less rain). The differences between forest and grass land soils is do more to there developmental age than to what type of plants grow on them-forest soils age faster than grass land soils but in time the two types can become indistigsiable, resulting in clay pan type soils.
Those soils that over time have become acid due to rain fall and chemical processes related to the movement of water threw the soil column will support those species that are adapted to acid conditions-though they may play a role in maintaing an acid environment they do not cause the acidity in general.