A quantitative, volumetric and dynamic study of the vegetation of 
the Pinus Taeda belt of Virginia and the Carolinas 
ROLAND M. HARPER 
(WITH ONE TEXT FIGURE) 
Introduction. The study of the vegetation of a given region 
may conveniently be divided into four stages. First, the various 
species of plants are collected, described (if necessary), and classi- 
fied taxonomically, and their local distribution determined. 
Second, they are classified ‘‘ ecologically,” by habitat, associations 
and adaptations, and the environmental factors analyzed. Third, 
their relative abundance is determined, in the region as a whole 
or in each habitat separately, and estimates made of the per- 
centages of evergreens, vines, parasites, plants belonging to certain 
families, etc. Fourth, the total bulk or weight of vegetation per 
unit area may be measured, together with the amount of new 
growth made in an average year, and the amount of water and 
other substances taken from the soil at the same time. 
Although this is perhaps the usual and most convenient order, 
and also corresponds pretty well with the historical development 
of the science of plant sociology,* it is by no means a fixed order. 
Any one of the stages may be omitted, and the fourth, which 
though rather difficult is simple enough, could very well precede 
the first. And of course it is not to be assumed that the foregoing 
outline covers everything that needs to be known about vegeta- 
tion. For example, it takes no account of generalizations about 
geographical distributions, times of flowering, colors of flowers, 
pollination and dissemination, studies of endemism and biblio- 
graphic history, and speculations about geological history and suc- 
cession, all of which have contributed many pages to the botanical 
literature. Comparisons with similar or neighboring regions are 
always appropriate, too. 
The region under ecules offers little attraction to the 
botanist who does not go beyond the first stage, and “cannot see 
* See Torreya 16: 138. June, 1916. 
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