How does soil pH affect animals and plants in the area? what is the effect of pollutants on the soil's pH?

Question

Help me pls..

Answer 1

Located some information using an ask jeeves search. If you scroll down here to 2) water pollution, and paraphrase, it says that acid rain can lower the pH of the soil to as low as 3. This washing away nutrients out of the soil and damages the plants in ways, it discusses fine root hair damage, that make it difficult for vegetation to recover from or thrive in that location.

Additional research reveals that the pH of the soil affect the types of plants that grow there. Most plants prefer a pH of 6 or 7, but some plants thrive in acidic soil. It lists several examples of these types of plants. What that will do is change the dominant vegetation of a given area, which could be a bad thing for that environment.

Answer 2

Many plants will only grow in specific pH ranges.  Thus soil pH is a determining factor for specific plant ecosystems.  As many animals will consume only specific plants, this in turn, makes soil pH a determining factor for animals in the ecosystem.  

Soil pH also affects nutrient availability in the soil.  Increasing nutrient availability increases plant growth, increasing plant growth increases food supply which will increase either (or both) the size of the individual animal and the number of animals per unit area (aka carrying capacity).

There is a secondary response to increased nutrient availability.  The increased nutrient availability will also increase the nutrient supply within the plant.  The animals consuming the plant will then require less plant materials to meet their nutrient requirement for maintenance.  This, in turn, allows the individual animals to grow more rapidly, and/or, the site to have a larger carrying capacity.



Soil pollutants may or may not affect soil pH.  It depends on the soil pH (is it acidic, neutral or basic) and the materials (are they acidic, neutral or basic) and how much pollutant is applied (rates are everything!).  If the pollutant is basic, and the soil is acidic (pH<6), soil pH will increase and approach neutrality (pH=7).  At this point, nutrient availability (overall, specific nutrients have different optimum soil pH ranges) will increase, several toxic nutrient availability (Al, Mn, Fe) will decrease and plant growth and nutrient density will decrease.  

A similar situation occurs when you add acidic pollutants to alkaline (pH>7.5).  However, if the pollutant causes pH to decrease below 6, or above 7.5, than soil nutrient availability will change and plant growth will be less than optimum.

One should note, different plants have different nutrient requirements and, thus, different optimum soil pH.  

Hope this helps.