18 BULLETIN 244, TJ. S. DEPARTMENT OF AGRICULTURE. 



As a result of repeated burnings the density of natural stands is 

 usually very variable. Occasionally second-growth stands have been 

 protected by surrounding cultivated fields and the watchfulness and 

 care of their owners. Such stands show striking regularity of tree 

 density and much quicker wood production than unprotected stands, 

 which is due to the influence of a protective mulch consisting of leaves 

 ("pine straw"), twigs, and bark. 



REPRODUCTION. 



Few of the valuable pines in the United States reproduce as vig- 

 orously as shortleaf. The regeneration is accomplished by seed and 

 by complete sprouting during the period of early life when the tree 

 is most susceptible to severe injury. Reproduction by means of nat- 

 ural seeding is successful and heavy, because of the frequent and full 

 seed crops, the lightness and short germinating period of the seed, 

 and the high resistance of the seedling to unfavorable conditions of 

 temporary shade and drought. 



Abandoned fields and openings made by lumbering, windfall (in the 

 tornado belt west of the Mississippi), and fires are quickly occupied 

 by shortleaf pine. Ten representative counties in western North 

 Carolina contain 393,670 acres of old-field stands of mostly pure short- 

 leaf pine. This is 14 per cent of the total area, or 27 per cent of the 

 forested area, of the counties. Such old-field stands characterize the 

 forest lands of the upland regions from Virginia southward and west- 

 ward throughout the range of the species. The extensive pineries 

 near Lakewood, N. J., are mostly pure stands of shortleaf (''two- 

 leaf") pine of similar origin. (PI. II.) In mixture with the inferior 

 pitch pine in New Jersey and loblolly pine in the lower or outer por- 

 tions of the shortleaf range, it has not successfully held its former 

 place of importance. The cause lies chiefly in the much closer utili- 

 zation of the shortleaf and the resulting relatively greater abundance 

 of seed trees of the associated species. In the southern mixed hard- 

 wood forest there has been a notable extension of the importance and 

 commercial range of shortleaf. This has been due to the successive 

 clearing, working, and "turning out" of fields and to the extensive 

 ranging of hogs. The hogs consume practically all of the oak and 

 hickory seed and at the same time prepare excellent seed beds for 

 shortleaf pine by uprooting soil and humus in the fall of the year. 

 Some seedlings, of course, are later destroyed by the same process. 

 The results of these two agencies, operative for periods of 75 to 200 

 years, have been cumulative and have produced marked changes in 

 the composition and density of the forest in various parts of the 

 South. 



On the National Forests of Arkansas natural reproduction is heavy 

 except on the cool northern exposures, and the encroachment of 



