activities. They may also be be- 

 coming less reversible due to the 

 spread of highly competitive en- 

 vironmental generalists such as 

 Australian pine ( Casuarina sp.), 

 cajeput ( Melaleuca quinquenervia ) , 

 and Brazilian pepper ( Schinus 

 terebinthifolius ) . 



The narrow beardgrass/three- 

 awn-grass/love grass prairie is a 

 unique assemblage that is closely 

 related to the muhly prairie. It 

 differs in that it occupies elevated 

 mesas, or outcroppings of oolite 

 rock that may have a thin covering 

 of marl soil. These prairies are 

 never very extensive but are locally 

 abundant as small patches in the 

 rocky glades. Three species of 



grasses, narrow beardgrass ( Schi- 

 zachyrium rhizomatum ), arrow feather 

 ( Aristida tenuispica ), and Elliot's 

 beardgrass ( Andropoqon elliotti ) are 

 usually present. 



6.14 CYPRESS 



Hilsenbeck et al. (1979) iden- 

 tify three types of cypress communi- 

 ties: 



(1) Open canopy (hatrack) cy- 

 press forests; 



(2) Cypress strands; and 



(3) Cypress domes. 



Olmstead et al. (1980) list a fourth 

 category, cypress heads, in their 

 study of Taylor Slough vegetation. 



The open canopy hatrack cypress 

 ( Taxodium distichum ) forest is 

 actually a combination cypress and 

 prairie since it occurs in such 

 close association with muhly grass 

 and sawgrass, on thin marl soils, 

 and at the lower end of the cypress 

 hydroperiod range in Table 23 (4 to 

 7 months). The name for this parti- 

 cular community derives from the 

 stunted growth form assumed by the 

 trees, which vaguely resembles a 

 bunch of hatracks. The hatrack 

 cypress typically provide less than 



5% of canopy closure making the un- 

 derstory vegetation quite important 

 in overall community structure. 



Cypress strands are elongated 

 areas having a hydroperiod of 4 to 

 10 months, in which cypress domi- 

 nates the canopy with red bay 

 ( Persea borbonia ) and strangler fig 

 ( Ficus aurea ) occassionally present. 

 Soil composition beneath the strands 

 varies from peaty marls to peats and 

 some mucks. In general, cypress 

 strands are confined to the eastern 

 margin of Taylor Slough, although 

 some are found on the margins of 

 Shark River Slough as well. 



Cypress dome forests are also 

 generally limited to the eastern 

 margin of Taylor Slough. They 



develop on peat soils with an 8 to 

 12 month hydroperiod. The struc- 

 tural geometry of the dome forest is 

 such that the largest trees are lo- 

 cated in the interior of the strand 

 on deeper organic soils and around 

 the central pond, and the shorter 

 trees with smaller diameters are 

 situated at the periphery of the 

 stand. This relative positioning 



results in the dome or bell-shaped 

 curvation that is characteristic of 

 this kind of forest. 



The canopy dominant is bald 

 cypress ( Taxodium distichum ), with a 

 typical height between 9 and 15 m 

 (30 to 50 ft). Canopy closure is 

 rather complete, producing a densely 

 shaded interior beneath it. The un- 

 derstory vegetation is not diverse, 

 except around the margins of the 

 forest and the edges of the central 

 pond. Epiphytes are common, occur- 

 ring particularly in the branches 

 and on the trunks of the smaller 

 peripheral trees. 



6.15 THICKETS 



Wax myrtle/saltbush thickets in 

 the East Everglades are situated on 



114 



