Soil Development

• Several factors play a role in the development of soils and hence, its productivity and ability to support plant life. The first of these factors is the parent material. Glacial activity produces several materials which can serve as the base for forest soils. These materials include loess or wind-deposited soils, glacial till or unsorted sediment, or outwash or sediment deposited from glacial meltwaters. Other factors include climate, existing vegetation, topography and time. Soils continue to form even today as rocks disintegrate through natural and manmade processes.
  
  

Types of Soils

• There are four soil orders associated with temperate, deciduous forests which determine the type of plants which live in these ecosystems: spodosols, alfisols, mollisols and ultisols. The U.S. Department of Agriculture developed the soil order system as a means to classify soils under a uniform system. Spodosol soils have low pH, which will favor acid-loving plants. Alfisol soils have low organic content but high organic content in plant life above ground such as heavily wooded areas. Mollisol soils are abundant in organic material. These soils can support a rich diversity of plant life. Ultisol soils occur where precipitation exceeds the ability to soil to absorb it, so you may find wetland-type plants and animals in these areas.
  
  

Recycling Nutrients

• Plants and animals ensure the health of forest soils by recycling nutrients within the forest ecosystem. When plants or animals die, the decomposing material releases nutrients in the soil which then can fuel additional plant and animal growth. The plants in turn provide food and habitat for wildlife, and the balance of the forest is sustained.
  
  

Productivity

• A productive forest will have a great diversity of plants and animals. It will also be able to support plant life through its entire life cycle. For example, if trees are able to reach their base height, cavity-nesting birds such as woodpeckers, owls and wood ducks will be able to find suitable nesting habitat in trees large enough to support them. Healthy soils can ensure a continued supply of food for wildlife. Fruit or nut-bearing trees may require years before they produce their first harvest. If soils are fertile, there is a continued cycle of growth, with wildlife able to find enough food resources.
  
  

Threats

• The greatest threat to forest soils and the organisms which depend on these habitats is pollution. Soil pollution occurs often from runoff, with agriculture being the primary source, according to the U.S. Environmental Protection Agency. These toxins can kill the micro-organisms, necessary for the continued health of the soils. They can also trigger chemical reactions which can release toxic chemicals into the soil. The survival of the plants and animals of deciduous forest depends on healthy forest soils.