48 BULLETIN 272, U. S. DEPARTMENT OF AGRICULTURE. 



posed chiefly of red maple, water oak, red oak, ash, honey locust, 

 hackberry, and red gum, in association with mature cypress. In 

 southeastern Mississippi a tract of 807 acres, mostly overflowed in 

 winter and spring, contains the following hardwood associates of 

 cypress, stated in the order of their relative importance : Ash, white 

 and red elm, red maple, red and tupelo gums, various oaks, hack- 

 berry, hickory, and cottonwood. In all of these higher glades groups 

 of pure cypress occur in the depressions, and elsewhere older trees 

 are scattered in mixture with the hardwoods. The gradual shifting 

 of the main currents during floods produces changes in the location 

 and height of the ridges in the glades, together with corresponding 

 changes in the composition of the forest due to the different moisture 

 requirements of ihe various species. 



Over the southern Atlantic Coastal Plain, mature red gum, over- 

 cup oak, water elm, water and Florida ash, and bitternut hickory 

 occupy the low ridges in the large river swamps. Tupelo gum, water 

 ash, and small amounts of cottonwood and water locust, along with 

 cypress, stand in water during much of the year. Two other types 

 in this region are found in the nonalluvial Dismal and Okefinokee 

 Swamps, and the mixed white cedar and cypress swamps from Vir- 

 ginia to Florida. The Okefinokee forest is made up essentially of 

 heavy stands of pure cypress over the younger and middle-aged por- 

 tions, and a dense hardwood forest with scattering veteran cypress 

 over the older-aged portions of the swamp (fig. 3) . Among the hard- 

 woods, black gum leads, and there is much white bay, red bay, red 

 maple, and willow and water oak. The more valuable yellow poplar, 

 red gum, and ash, if present, are in very small quantities. The 

 white cedar peat swamps contain varying mixtures of cypress and 

 white cedar, with pond and slash pine around the borders. 



Along the swamp borders cypress closely meets the many conifers 

 and hardwoods which compose the upland forests of the Southeast. 

 The small cypress ponds of the flat, pine-barren type contain small 

 amounts of water gum, a dwarf form of the black gum, while pond, 

 spruce, and slash pines are encroaching actively from the outside 

 as the ponds become drier through the destruction of the surrounding 

 pine forest. 



YIELD. 



In pure stands and in the better cypress regions of the Southern 

 States, particularly Louisiana and Florida, virgin cypress yields of 

 8,000 to 14,000 board feet per acre are not uncommon over tracts 

 several hundred miles in extent. The size of the trees and density, 

 or number of trees per acre, is very irregular. In a few localities 

 manufacturers are now cutting bodies of pure cypress containing a 

 total of up to 100,000,000 feet, which will average more than 20,000 

 feet per acre. 



