The Spread of Timbered Areas in Central Texas

Abstract

State Forester o[ Texas Lying in the south-central part .of Texas is a region known as the Edwards Plateau. This is a deeply eroded, limestone country forming the southern extension of the Great Plains and terminating abruptly on the south and east in an escarpment zt00 to 1,000 feet in elevation, known as the Balcones Escarpment. South o.f this escarp-ment lies the Rio Grande Plain and east of it are the great agricultural. prairie belts of east-cent.rail Texas. Northward extendin,g to the Red River, and northwestward to the Breaks of the Plains is a vast territory consisting of carboniferous and red beds deposits and granitic areas which may be .termed' the central denuded region of north-central Texas. T.he Edwards Plateau proper consists of limestones ef the older cretaceous formation, faulted and uplifted during tertiary time and since then eroded into hills and narrow canyons with stretches of rolling prairie between. The area' of greatest erosion and dissection is ,toward the eastern and southern escarpments, the region farther west gradually flattening out until it merges into•the Great P.lains. Erosion has also •played an important part in the transformation .of ,the denuded region, causing steep bluffs and isolated buttes, deep gorges and long, even slopes often covered with broken rock strata. The Edwards Plateau and the surrounding regions have during recent years been .undergoing a remarkable transformation from grass, lands and exposed rock f.ormations to a forested condition. This ,is ,the more remarkable when it is realized tha.t the average rainfall does not exceed g5 inches .per year and that it is a region of little humi.dity, intense sunlight, and rapid evaporation. Such conditions are conducive to grassland vegetation. It is not fair to assume .that this region has hitherto been treeless, but throughout central Texas as a whole 'f.orest growth has been confined to the more .eastern s•1opes of the Edwards P,lateau' and to the canyons, stream borders and occasional steep bluffs and mesa tops in the regions northward. The present forests consist 'of three principal cl,asses: along streams and canyons, on hills and bluffs, and prairie growth.