THE SOUTHERN CYPRESS. oo 
seed, which increases the susceptibility of the immature seedling to 
winter freezing. 
Stands of mature cypress, but rarely any of young growth, occur 
on the ridges in the undulating swamp bordering such alluvial rivers 
as the Santee, Apalachicola, and Mississippi (fig. 2). The recent up- 
building of many of these ridges by the deposition of silt and other 
material during floods is clearly apparent; likewise the later excava- 
tions of some of them by swift flood currents, exposing the embedded 
bases of mature standing cypress trees. With the natural limitation 
of reproduction to the very wet sites, second-growth cypress is irregu- 
larly distributed in swamps, being found mostly in openings and 
especially on newly formed low, wet mud bars and banks (PI. VIIL). 
Reproduction is notably more abundant in localities where cutting 
has been conservative than where logging has made a clean sweep. 
The early float method of logging destroyed very little growing 
stock, the pull-boat method considerable, and under present methods 
of clean cutting the overhead-cableway skidder effects almost com- 
plete destruction of any part of the forest which happens not to be 
taken. 
Evolution of the Okefinokee Swamp.—The relation of cypress repro- 
duction to the progressive changes in the history of large inland 
swamps is interesting. This relation is intimate, and the compara- 
tive ages of various portions of the swamp—for example, the Oke- 
fnokee Swamp in Georgia—can be told approximately by the age and 
distribution of cypress in the forest stand. 
Remnants of the original lake may be seen in the Okefinokee 
Swamp in the scattered bodies of open water. These are bordered 
by “‘prairies,”’ or treeless marshes of considerable width (Pl. VID). 
In passing outward from the central open water toward the higher 
or older portions, one successively finds (a) widely scattered clumps 
of young, slow-growing cypress which obtained a foothold on the 
vegetable mounds or tufts, (b) dense stands of slender pole cypress, 
(c) mature stands of large-size trees where the swamp floor of humus 
and mulch has become quite stable, (d) overmature cypress trees 
scattered in a stand of black gum and white and red bays, and (¢) on 
the outer and oldest portion, a high forest of pure hardwood with 
hardly a remnant of the former cypress stand. ‘These successive 
stages are well shown in figure 3 on page 22. At the extreme edge 
of the swamp this type changes abruptly to a pure forest of either 
longleaf or slash pine over the broad, sandy pine flatwoods. The 
marshes range in size from a few rods in diameter (‘alligator holes’’) 
to several hundred acres. One small “prairie” contained a few 10- 
year-old saplings surrounded by a large pole stand 140 years old, 
which in turn was inclosed by a marginal, even-aged stand of thrifty 
96612°—Bull. 272—15——3 
