A NATIONAL PLAN FOR AMERICAN FORESTRY 347 



land clearing was at its height. The forest is remarkably evenly dis- 

 tributed. The proportion varies from 50 to 75 percent as between 

 the larger drainages. A considerably higher percentage of the moun- 

 tain and the coastal plain provinces is forested than of the piedmont 

 Erovince, but, as already stated, only 24 counties in the region show 

 ?ss than 40 percent forest cover, and only 2 less than 20 percent. 



ORIGINAL AND PRESENT CHARACTER OF FOREST AS INFLUENCING 

 EROSION AND STREAM FLOW 



Comparatively little of the virgin timber of the region now remains. 

 A large area has been cleared for agriculture. Some of it went back 

 to forest during the Civil War, and some has again been cleared. On 

 the piedmont farm woods are typically interspersed with agricultural 

 land. But on the poorer sandy lands and alluvial bottom lands of 

 the coastal plain, and in the rougher portions of the mountains there 

 are extensive and continuous forests. 



In the mountains, about 70 percent of the area is in forest. This 

 is largely a mixture of oaks, hickories, tulip poplar, ash, maple, beech, 

 basswood, chestnut, and a large number of other species. Repeated 

 culling of the better quality woods has converted much of the original 

 high-grade forest into an inferior one. Fire has resulted in further 

 depletion of the culled stands, until now the forest in many places is 

 for the present almost worthless commercially. The most obvious 

 effect of fires on watershed protective values is the destruction of leaf 

 litter. Litter under a good forest cover in the mountains accumulates 

 to a depth of several inches; its dry weight, in one study made by the 

 Appalachian Forest Experiment Station, was found to be as much as 

 13,000 pounds an acre. Other studies by the station show that it 

 may absorb up to four and one half times its own weight of moisture. 

 This retention of water by litter may itself be important in lessening 

 run-off from heavy storms, but its effect has been shown by experi- 

 ments in this region and elsewhere to be completely overshadowed in 

 value by the favorable effect of litter upon absorption of water into 

 the soil below. When litter is destroyed, as by fire, the soil soon be- 

 comes less porous, and less able to store large quantities of water. 

 Fire protection in the mountain region is variable. In some places, 

 as on the national forests, fire losses have been kept to a reasonably 

 satisfactory figure. State and county effort has developed well in 

 part of the region. Private efforts at protection of the forest against 

 fire are sporadic. 



The forests of the piedmont are characteristically a mixture of 

 hardwoods and pines. Pure hardwood stands are common, as are 

 pure stands of shortleaf and Virginia pines at the north, and of short- 

 leaf and loblolly at the south. In places a mixed hardwood forest is 

 found. The farm woodlands, being isolated, have suffered less from 

 fires than have the large continuous areas of forest land in the moun- 

 tains, and the cutting methods applied to them have probably been 

 less destructive than those employed elsewhere. Grazing, which is 

 permitted in many farm woodlands, is a severe handicap to young 

 growth. 



On the coastal plain, from Virginia south, the original upland forest 

 was dominated by longleaf pine, although on the more compact clays 

 and silts loblolly pine, and in South Carolina slash pine took its place. 



