60 



TIMBER PINES OF THE SOUTHERN UNITED STATES. 



■2l(iBf5.5|7.0f 8J--T- 9.6--H ' -5-* -• 1 3.0-- f -1 4.5-- ^f- - • 1 6.0- - -f- -■ 1 8.0 



ip.5---f---20.5--f-- 21.3- 



DIAMETERS. 

 IN INCHES. 



Klo. 8 Growth of I.oiiKlcuf IMue; HfiKht, ili.tinotcr, niiil culiii- contenta of average treoa .at 10. 20, etc., years of age. 



CONDITIONS Ol'' DEVELOPMENT. 



Dcmandx upon xoil mid rUiiiatr.—\u its deniiiucLs upon tlie soil this pine is to be counted among 

 the most fru>;al us far as mineral constituents, wliieli are considered as plant food, are coneerued, 

 ifonlytlie mechanical (londititms \vhi(-li iulluenee favorable soil moisture are not wanting. It 

 thrives best on alight siliceous soil, loamy sand or pebbles or lij^lit sandy loam, with a slightly 

 clayey sub.soil sufficiently porous to insure at least a partial undcrdrainage and to permit unim- 

 peded <leveloi)ment of the long taproot. Whenever the tree meets an obstacle to the development 

 of this root it remains more or less stunted. 



The luxuriance of the growth and increase in size of the limber, however, is greatly inllu- 

 enced by tiie ([uantity of clay present, i)articularly in the deep subsoil, which improves mechanical 

 and moisture conditions. Tliis is strikingly exhibited in the timber of the level pine tlats west of 

 the Mississippi liiver, although the surface drainage is almost wanting and tlie untlerdrainuge 

 through the loamy strata slow, so that the surftice of the soil remains damp or water-soaked for 

 the greater part of the year: tlie stand of tind)er of tirst -class dimensions exceeds considerably 

 that of the rolling pine uplands on the Atlantic slope and the lower part of the pine belt in the 

 Ka.stern (inlf region, which are poorer in clay. Evidently, although the underdrainage is less 

 perfect, the moisture conditions during the dry .sea.stm of the year, the time of most active growth, 

 mu.st be nuist favorable. The .same fact is apparent in the upi)er part of the coast pine belt in 

 Alabama and Mississippi, whert* upon the same area, with a smaller number of trees, the crop of 

 timber may be considered almost twice as heavy as that found on the \nuo liarrens proper farther 

 south. On tlie soil of fine, clo.sely compacted .sand, entirely ilelicient in drainage as found in the 

 so-called pine nieadows along the coast of western Florida, .Vlabama, and Mississippi, as well as 

 on the siliceous rocky ridges of central and northern Alabama, the tree is so stunted as to be of 

 little or ni> value for its timber. 



"It is neither temperature alone, nor rainfall and moi.sture conditions of the atmosphere alone, 

 that influence tree growth, but the relation of these two climatic factors, which determiues the 



