Historically, sheet flow from 

 Lake Okeechobee through the Ever- 

 glades has followed a south by 

 southwest curve as outlined by the 

 arc of Shark River Slough. Some of 

 this sheet flow, however, has been 

 transverse to the main axis of the 

 Miami Rock Ridge, the Everglades 

 Keys, and the Rocky Glades. This 

 causes erosion of the thin layer of 

 overlying marl soils and solution of 

 the underlying Miami oolite, leading 

 to a solution riddled topography. 

 These erosional surfaces cut across 

 the limestone toward Taylor Slough 

 and the southern slope. This nat- 

 ural evolution of morphology is com- 

 plicated by vegetational patterns, 

 peat deposition, marl formation, and 

 rock plowing for agricultural put — 

 poses. (Rock plowing refers to an 

 agricultural practice in which marl 

 soils are dug up and crushed to 

 facilitate planting and drainage). 



Upper, Middle, and Lower Taylor 

 Slough 



The northern boundary of this 

 segment is located where SFWMD 

 Canal 31-W intersects the main chan- 

 nel of Taylor Slough (Olmstead 

 et al. 1980). This area is referred 

 to by Olmstead et al. (1980) as 

 upper Taylor Slough, a rather well 

 defined, 5.5 km (3.4 mi) long seg- 

 ment running from the intersection 

 of the slough and the canal levee 

 structure L-31 W south to State Road 

 27, Anhinga Trail. Middle Taylor 

 Slough refers to that segment of the 

 slough from State Road 27 south 7 km 

 (4 mi) (Olmsted et al. 1980). The 

 slough is joined in this segment by 

 a large arm from the east. Lower 

 Taylor Slough refers to the segment 

 lying south of this point to Florida 

 Bay. 



The bedrock of Taylor Slough is 

 broadly concave with the central 

 portion averaging only 90 to 120 cm 

 (3 to 4 feet) lower than the mar- 

 gins. The center of this broad 



depression in the Miami oolite var- 

 ies from 0.2 to 2.0 m (8 in. to 6.5 

 ft) below the margins. However, 

 marl soils and peat deposits tend to 

 obscure and smooth over the under- 

 lying variations in bedrock. 



The slough itself is charac- 

 terized by comparatively dry areas 

 in the north that are dominated by 

 muhly prairies ( Muhlenbergia 



filipes ) (Hilsenbeck et al. 1979). 

 Interspersed in the upper part of 

 the slough are limestone outcrop- 

 pings (the Everglades Keys), which 

 are colonized by pines and tropical 

 hardwoods. A small but significant 

 portion of the land is former agri- 

 cultural land, now in the hands of 

 Everglades National Park. The cen- 

 tral portion of the upper slough is 

 a relatively wetter area dominated 

 by sawgrass ( Cladium jamaicensis ) 

 and spike rush ( Eleocharis cellu - 

 losa ) marshes. 



Farther south, middle Taylor 

 Slough broadens and becomes vegeta- 

 tionally dominated by sawgrass, 

 spike rush, and willow ( Salix caro - 

 liniana ) marshes (Olmstead et al. 

 1980). Toward Florida Bay the 



freshwater slough vegetation is 

 gradually replaced by buttonwood 

 ( Conocarpus erecta ), mangrove foi — 

 ests, salt barrens, and tropical 

 hardwood hammocks. 



Southeast Coastal Glades 



Lying to the east and south of 

 the main stem of Taylor Slough is 

 another band of what Puri and Vernon 

 (1964) refer to as gulf coastal 

 lagoons. Upland of this band are 

 freshwater marl prairies referred to 

 in Figure 7 as the coastal drainage 

 region, which serves as the only 

 source of fresh water outside of 

 direct rainfall to extreme upper 

 Florida Bay. Farther east and north 

 these marl prairies drain into the 

 series of sounds that separate 

 Florida Bay from Biscayne Bay. 



19 



