The Trees of Texas 1< 



water. In this way long continued heavy rains are required be- 

 fore the excess water begins to flow 7 off into streams and rivers. 

 The water which percolates down into the soil gradually runs 

 aw r ay to feed streams and springs, and thus maintains their 

 steady flow throughout the year. It is a very noticeable fact 

 that springs are much more common in forested lands than in 

 the open, and that they usually cease to flow when the forest 

 is removed. The water-holding power of a watershed is much 

 greater if it is covered with timber than with any other vegeta- 

 tion, but grassy plains catch and hold much more water than 

 cultivated areas. The removal of forests, and the cultivation of 

 the areas once occupied by them, has given rise to the various 

 floods which now 7 occur on many rivers throughout the country. 

 Concerning erosion, it has been estimated that 1,000,000,000 tons 

 of sediment are annually pouring into the seas from the rivers 

 of the United States. This material is derived from the surface 

 layers, the richest part of the soil, and its land value, the annual 

 loss, would exceed all the land taxes of the country. The soil 

 actually removed does not, however, constitute the entire danger. 

 The surface of the hillside areas frequently become so gullied 

 that they can no longer be tilled, and all productive power is lost. 



SHADE TREES 



Aside from their more readily estimated value for fruit, timber, 

 and fuel, trees are valuable for shade and ornament. The orna- 

 mental shade tree ministers not only to our physical comfort, 

 but also to the aesthetic pleasures which come to us through a per- 

 ception of beauty. The chief value of trees for city streets, lawns, 

 and parks is due to the beauty which can be developed by their 

 use. It is a value not always appreciated by all, and one which 

 should be enhanced by education. 



There is a growing sentiment throughout the country in favor 

 of the planting and care of shade trees. In the past, each owner 

 has planted along his property such trees as he saw fit, and given 

 them such attention as his knowledge and circumstances permit- 

 ted. This has resulted in miscellaneous collections of trees, de- 

 void of design, harmony and adaptation of means to an end the 

 very principles upon which beauty depends. 



In many of the cities of this country the work of planting and 



2 Trees. 



