354 A NATIONAL PLAN FOR AMERICAN FORESTRY 



forage and yet maintain satisfactory watershed conditions. Control 

 of fire, often set purposely, is far more necessary than any great 

 change in cutting methods. Adoption by landowners of the stand- 

 ards set up in the section of this report entitled "Protection Against 

 Fire " would satisfactorily meet watershed protection needs on private 

 forest lands. 



In Georgia, Florida, Alabama, and Mississippi, good fire-control 

 organizations have been developed in some localities but only 20 

 percent of the forest area is protected. Until better fire control can 

 be provided or until local woods-burning practices change, it will be 

 impossible to get adequate protection. In 1929 and 1930 about 29 

 million acres, or 40 percent, of the total forest area not now pro- 

 tected (about 71 million acres) burned over each year. Where fires 

 annually cover large areas of forest land, not even a scanty litter 

 cover can develop. 



Probably the largest fire-control effort of a single landholder is that 

 of the Great Southern Lumber Co., in southeastern Louisiana. This 

 company has succeeded in protecting its lands from fire largely 

 because it has bought many of the small intermingled holdings and 

 put considerable forest acreage under a tight fence. The latter has 

 not only interfered with trespass and eliminated grazing fires but also 

 excluded the hogs which destroy young longleaf seedlings. 



Cattle grazing on forest areas is widespread, especially in the pine 

 regions, but probably does little if any damage to the watersheds. 

 Only locally, and usually only on farms, does overgrazing of conse- 

 quence occur. 



Forest conditions such as those described do not tend to regulate 

 stream flow or to prevent erosion. The open forest does not develop 

 a full litter cover even if unburned, and grass often occupies the 

 space between the trees. As indicated in the introduction to this 

 section, grassland has a higher surface run-off rate than forest. Thus 

 a reduction in the density of the forest tends to increase flood heights. 



How far a change from good forest cover to scrub or sprout forest 

 cover affects surface run-off and erosion in this region is unknown. 

 Data taken by the Southern Forest Experiment Station in the silt 

 loam uplands of northern Mississippi show that a scrub forest helps 

 to retard surface run-off in times of heavy rain. A dense scrub or 

 sprout forest can probably prevent erosion, but all too often the sprout 

 stand to which cutting and fire convert a high forest is an under- 

 stocked stand. Such a forest certainly burns more frequently than 

 the forest it succeeds. 



STREAM FLOW 



The streams coming from the Blue Ridge highlands have a greater 

 annual run-off than any other streams of the East Gulf drainages, the 

 discharge being approximately equivalent to 30 inches of precipitation 

 over their watersheds. Those from the piedmont and the coastal 

 plain have a run-off equivalent to a precipitation of 20 to 25 inches. 

 Fluctuation in flow is much less for the highland streams than for 

 those of the piedmont and coastal plain; their ratio of minimum to 

 maximum flow is about 1 to 100, whereas the Tallapoosa, for example, 

 fluctuates from 65 to 102,000 second-feet, a minimum to maximum 

 ratio of 1 to 1,569. The Army Engineers report that "in common 

 with all rivers rising in the Appalachian Mountains, the (Apalachicola 

 River) system exhibits a wide periodic fluctuation in volume of flow. 



