THE TIMBER OF THE EDWARDS PLATEAU OF TEXAS; ITS 

 RELATION TO CLIMATE, WATER SUPPLY, AND SOIL. 



INTRODUCTION. 



That a forest or other heav}' growth oi vegetation exerts an impor- 

 tant influence in conserving the water supply, in preventing or checking 

 floods, and in resisting the erosion of soil, scarcel}^ requires demon- 

 stration in these pages. Most Texans, at an}" rate, have had abundant 

 opportunit}" to observe how a heav}" growth of grass on prairie slopes 

 will hold the soil at the time of a heavy cloudburst, which, on denuded 

 soils, plows out great gulches and carries away thousands of cubic 

 yards of earth. Or those living in the rough, mountainous region of 

 south-central Texas ma}' have noticed how, after a violent downpour 

 of rain, the water rushes down the sides of bare, steep hills with a 

 power which carries not only any remnants of soil, but the fragments 

 of rock as well, and scoops out the bottom of the gorge down to a solid 

 rock bed; whereas when the sides of the gorge and perhaps the hills 

 above are heavily timbered, the organic debris drinks up and detains 

 the water, so that not only is this heav}" covering of leaf mold not 

 washed away, but the water does not acquire momentum and volume 

 sufficient to sweep out the channel of the gorge itself. 



Older communities, after costly experience with floods, with the 

 failure of springs and streams, and with the destruction of valuable 

 farming areas, acknowledge that there are some areas from which 

 forest covering must not be removed. It is quite within experience 

 that the difference between two similarly located regions, one of them 

 abounding in fertile farms and orchards and pastures, the other a bare 

 waste of naked hills and water-washed lowlands, may be due to the 

 treatment given to the native forest vegetation which, to begin with, 

 covered the hillsides. Our neighbors of the older States of the South 

 who live in the Coast Plain forest belt of sandy clay soils (the same as 

 the Lignitic Belt of Texas) realize, after the loss of whole farming- 

 areas by erosion, that, within this region at least, certain portions must 

 be left timbered for the protection of farm lands. It is a familiar 

 fact that in the south of France, when the short-sighted policy of 

 selling the Government forest lands and permitting their denudation 



7 



