40 HARPER: VEGETATION OF THE PINUS TAEDA BELT 
the woods for the trees.” As seems to be the case wherever 
Pinus Taeda (and the same might be said of several other pines) 
is the prevailing tree,* nearly all the plants are of common and 
widely distributed species, which have been described long ago. 
In the second stage, very little has been done in this region, 
largely because of inherent difficulties which will be explained 
below under the head of vegetation. This paper is chiefly con- 
cerned with the third stage, determining the relative abundance 
of the species in the region as a whole, which is done by means 
of notes accumulated during about seventy-five hours of field 
work. For the fourth stage, volumetric and dynamic studies, 
very few accurate data are available as yet for this or any other 
part of the world, but some rough estimates are attempted, to 
illustrate a method which should be followed in all future critical 
studies of vegetation. For it cannot be disputed that the annual 
growth of vegetation, and particularly the amount of food taken 
from the soil in a given time, is closely correlated with enviro- 
mental factors, and should be a better indication of soil fertility 
than any static studies of vegetation, whether qualitative or 
quantitative. Soe: : ; 
Location and boundaries of the region. The Pinus Taeda 
-belt proper of the Atlantic coastal plain, as mapped by the 
writer a few years agof (in Fic. 1 the same map is reproduced), 
is regarded as bounded on the north by the James an Appomattox 
Rivers. From Petersburg, Va., to the vicinity of Rocky Mount, 
N. C., it borders the fall-line, which there (as all the way across 
Virginia) runs just about north and south. Thence to near Fair- 
ax, S. C., it passes northwestward into a belt of low red hills, a 
continuation of the Eocene red hills of Georgia, Alabama and 
Mississippi. From Fairfax to near Charleston it is bounded on 
the south by the pine-barrens with Pinus Elliottii; thence to near 
the mouth of the Santee River it is separated from the coast by a 
narrow coast strip, with marshes, islands, and a good deal of silty 
* See Torreya 7: 44-45. 1907; 9: 217. 1909. This applies to habitats, though, 
rather than to regions. For example, Pinus Taeda is the common i 
Apalachicola bluff region of Middle Florida (see 6th Ann. Rep. Fla. Geol. Surv. 
212-215, 353, 355), where many rare plants grow; but the pine is mostly near the 
top of the bluffs and the rare plants lower down. 
} Bull. Torrey Club 37: 407, 592. 1910-11. 
