THE SOUTHERN" CYPEESS. 33 



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. VIII). 



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 -cable way skidder effects almost com- 

 plete destruction of any part of the forest which happens not to be 

 taken. 



Evolution of the Olcefinokee 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- 

 finokee 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 VII). 

 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 (e) on 

 the outer and oldest portion, a high forest of pure hardwood with 

 hardly a remnant of the former cypress stand. These successive 

 :'<■-> iin; 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 

 longlcaf or sJa.^li pine over the. broad, sandy pine flatwoods. The 

 margins i.hi;/<- 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 fcUTU Was hnl<, <<| by a, marginal, even-aged stand of thrifty 

 00012°— Bull. 272 — J 5 3 



