40 The New York State College of Forestry 
COMPETITION BETWEEN SPHAGNUM AND VASCULAR BOG 
SPECIES 
With regard to the interaction between vascular plants and 
sphagnum, it should be noted that the taller growth and shad- 
ing effects of the former — notably of shrubs and young black 
spruce —tend to suppress the sphagnum. In, this connection 
it has been mentioned that S. recurvum makes a tall climbing 
growth about the stems of the vascular plants thus starting 
the mound formation. A study of the bog in late autumn 
(November 1) after leaf fall, showed that all the species of 
sphagnum had made rapid growth during the cooler months 
of September and October and that thus they had materially 
increased the thickness of the living sphagnum cover while free 
from the shading effects of competing shrubs and_ sedges. 
Thus by reason of their continued growth, during the dormant 
stage of their competitors, they were able to make gains which 
would be compensated for by the rapid development of new 
shoots and leafage of the vascular plants in the following 
spring. In the case of black spruce, however, where the opaque 
foliage is permanent, no such compensating growth of sphag- 
num occurs and thus it becomes suppressed beneath these dense 
widely spreading young trees. The rise of the sphagnum 
blanket about them is very notable so that the spruces seem to 
stand in depressions in the general bog surface. Fig. 17. 
VEGETATIVE PROPAGATION IN THE BOG 
The ability to multiply and oceupy ground by rapid vegeta- 
tive propagation is pretty nearly a universal characteristic 
among plants in the Adirondack bogs. The sphagnums are, 
of course, notable for the vigor and rapidity of their vegetative 
propagation. The whole scheme of bog evolution rests upon 
this fact. The living surface carpet of sphagnum is made up 
of shoots from old plants gradually dying below where for a 
season the old stems retain their more or less erect position, 
becoming flattened and compressed by the weight of the surface 
erowth and especially by the winter load of snow and _ ice. 
