Buffalo National River Forests

The plant communities that compose the forests of the Ozark Mountains are composed mainly of Oak-Hickory communities; however, many other types of plant communities exist and these communities are much influenced by the geology of the area. Gradients of plant diversity and species composition can be seen on almost any mountainside that is of moderate elevation. Plant community composition within the Ozark Mountains exhibit gradients of species change similar to other mountain systems; however, these gradients are due to the accessibility of water and nutrients and not temperature or elevations, as is the case with other mountainous regions in the U. S.

Typically, ridge or mountaintops in the Ozarks are comprised of Post Oak communities, and in some places, Short Leaf Pine. From this dry ridge top, the communities shift toward more mesic species as elevation drops. This is due primarily to the availability of water as a function of soil characteristics. When abrupt changes in lithology occur, water in the bedrock may flow laterally until it intersects a valley wall or hillside. When this occurs, springs and seeps are formed. Another geologic influence upon the species composition of plant communities is the gradient in soil acidity between the more acidic Boston Mountain soils and more alkaline Springfield Plateau soils. Generally, soil derived from the Boston Mountain ecoregion are more acidic due to the lack of calcium carbonate that is more abundant in the older formations of the Springfield and Salem Plateaus. This transition creates an abrupt gradient of plant community diversity because most plants require a more alkaline type soil; therefore, areas around the borders of these plateaus can be more diverse as compared to the Boston Mountains proper.