Excerpt from Literature Review Therrell, Matthew D. and David W. Stahle. A Predictive Model to Locate Ancient Forests in the Cross Timbers of Osage County, Oklahoma. The Cross Timbers are upland forest, dominated by post oak and blackjack oak. They are located in Oklahoma, northeastern Texas, and southeastern Kansas, on the transitional boundary between the eastern deciduous forest and the Great Plains. The soils on which they are found are derived from sandstone.
Trees grow very slowly because of the scarcity of nutrients in the soil and because of low rainfall.
Therefore they are generally no more than fifteen meters tall and of little use for timber. Much of the forest on low ground has been cut to make way for agriculture but on steep slopes the trees tend to have survived. Niotaze-Darnell soils cover 11,308 hectares in Oklahoma s southern Osage county. The researchers tested their model by visiting fifty randomly selected sites in the county, and found ancient forest on 92 ha of the 125 ha surveyed. White, David L. and F. Thomas Lloyd.