Tree growth differences are also significant. If you picked the Laidig as the best and the soil on the far left as the worst, you are correct on both counts. The knowledge that you will develop during this course will enable you to make a more accurate assessment of productivity. The Maine soil supports a stand of spruce and fir trees while the PA soil is from an agricultural field. Soil formation, or pedogenesis is a complex combination of processes with one or several being dominant depending upon the influence of environmental factors.
Evaporation exceeds precipitation, but the soil profile is moist at some time during the year.
Ca is adsorbed by plant roots and stored. When the plant dies soil fauna and flora decompose the tissue, recycling the Ca in soluble form. Biomass turnover is rapid and soil Ca supply is maintained. Little translocation takes place in the profile and the soil remains fertile. This soil-forming process is termed calcification .