Introduction

The cross timbers are a mosaic of forest, woodland, savanna, and prairie vegetation located in portions of Kansas, Oklahoma, and Texas (Figure 14.1). Nonetheless, two woody species characterize the cross timbers: post oak (Quercus stellata; Figure 14.2a) and blackjack oak (Quercus marilandica; Figure 14.2b) (Dyksterhuis 1948; Hale 1955; Rice and Penfound 1955). There are an estimated 4.8 million ha of cross timbers located between 38° N latitude in southeastern Kansas and 32° N latitude in north central Texas (Küchler 1964; Engle and Stritzke 1992). Approximately half (2.5 million ha) of the cross timbers are in Oklahoma (Rice and Penfound 1959; D. D. Dwyer and Santelman 1964). The cross timbers form two distinct bands of vegetation in Texas, known as the western and eastern cross timbers (Figure 14.1). These formations were referred to as the upper and lower cross timbers, respectively, by early European settlers due to their location along the Red River (Foreman 1947).

Josiah Gregg, an entrepreneur who was active in the region during the 1840s, left an apt description of the cross timbers that is relevant today: