E. Transformation -alteration of materials within the soil profile. Conversion from one form to another 1. Weathering of parent material - physical and chemical breakdown of the parent material slowly but continuously provides new mineral material to the soil profile from below. Evergreen Forest - slow cycling, plant holds nutrients, not returned to soil, little humus in soils. Controls exposure to erosion.
Animals affect soil structure.
Large animals compact the soil, reduce air space C. Parent material - affects both soil texture and nutrient supply 1. Texture - type of rock influences weathering rates and size of particles. More C-H exchange sites. Sandstone, beach deposits, do not weather into clays. Fewer C-H exchange sites.