Shortleaf Pine (Pinus echinata) in Bryan County, Oklahoma

Abstract

A study of the shortleaf pine was conducted along its western periphery of range in Oklahoma. A mixed pine-oak stand located in Bryan Co. was selected for sampling. Data on composition, age, growth, and stand history were obtained. Some of these data, as well as a map of the Oklahoma distribution of Pinus echinata, are presented. Data from this stand are not significantly different from data of comparable stands farther east. It is speculated that fires and selective cutting have favored persistence of this species in this peripheral stand. I studied a stand of shortleaf pine, Pinus echinata (nomenclature follows that of Waterfall, 1962) at its western periphery of range during the summer, fall, and winter of 1962. The shortleaf pine has never been studied at its western periphery of range in the state, but some studies have dealt with P. echinata farther east, e.g. Little and Olmsted (1931), Little (1938), Bruner (1931), Duck and Fletcher (1945), and Rice and Penfound (1959). Pinus echinata occurs over most of eastern North America (Preston, 1961). It is a species with a wide ecological amplitude known to occur as a component of a number of forest types, on many different soils, and under several types of climates (Society of Amer. Foresters, 1932). The distribution of shortleaf pine in Oklahoma is mainly southeastern (Duck and Fletcher, 1945), however, it is known to occur in a number of areas not discussed by these authors. The Oklahoma distribution of this species, as ascertained by extensive reconnaissance, is presented in a map (Fig. 1). Along its western periphery in Oklahoma, it has discontinuous distribution, and in some areas there are essentially pure stands. This phenomenon has been discussed by Turner (1935). Generally the shortleaf pine occurs on well drained though poorer parts of upland habitats. This is especially true for stands found along the western periphery. An 80-acre stand located in Bryan Co. was selected for sampling. The present owner, Mr. Samuel Tigert, acquired this acreage in 1938, but lived in the same general area a number of years prior to that date. DESCRIPTION OF THE STUDY AREA. The study area is underlain by a sandy stratum, the Paluxy sand, and is bounded, except on the north, by the Goodland limestone, both of Cretaceous age. (At present no de-