94 Types of Aquatic Environment 



two outflowing streams, St. Mary's and Suwannee 

 Rivers. The waters are deeper over the eastern part of 

 the swamp, the side next the barrier; and here the 

 vegetation is mainly herbaceous plants, principally 

 submerged aquatics, with occasional broad meadow- 

 like areas overgrown with sedges. These are the so- 

 called ''prairies." The western part of the swamp 

 (omitting from consideration the islands) is a true 

 swamp in appearance being covered with trees, prin- 

 cipally cypress. A few small strips of more open and 

 deeper water (attaining 25 feet) of unique beauty, 

 owing to their limpid brown waters and their setting 

 of Tillandsia-covered forest, are called lakes. 



The whole swamp is in reality one vast bog. Its 

 waters are nearly everywhere filled with sphagnum. 

 Whatever appears above water to catch the eye of the 

 traveler, whether cypress and tupelo in the western part 

 or sedges and water lilies on the "prairie," everywhere 

 beneath and at the surface of the water there is sphag- 

 num; and it is doubtless to the waterholding capacity 

 of this moss that the relative constancy of this great 

 swamp on a gently inclined plain near the edge of the 

 tropics, is due. 



Climbing bogs — In-so-far as swamps possess any basin 

 at all they approximate in character to shallow lakes; 

 but there are extensive bogs in northern latitudes that 

 are built entirely on sloping ground; often even on 

 convex slopes. These are the so-called ''climbing 

 bogs." They belong to cool -temperate and humid 

 regions. They exist by the power of certain plants, 

 notably sphagnum, to hold water in masses, while 

 giving off very little by evaporation from the surface. 

 A climbing bog proceeds slowly to cover a slope by the 

 growth of the mass of living moss upward against 

 gravity, and in time what was a barren incline becomes 

 a deep spongy mass of water soaked vegetation. 



