FLORAL DESCRIPTION OF MARCO SHORES DEVELOPMENT SITE 



Eric Heald 



Program Director 



Tropical Bio-Industries Development Co. 



Miami, Florida 



The proposed development tract 

 covers the land lying between 

 Macllvaine Bay in the south and the 

 old "Belle Meade Grade" in the north 

 and extends 4,827 m from east to 

 west. The western boundary is State 

 Road 951. The tract includes some 

 farmed land in the northeast corner, 

 a golf course and airport, and an 

 excavated lake known as Lake Marco 

 Shores . 



The flora of the tract was exam- 

 ined from the air and on the ground 

 in October and November 1976. Aerial 

 photography from 1962 and 1974 at a 

 scale of 2.54 cm = 304.8 m was used 

 to locate various large-scale plant 

 associations. Ground observation 

 confirmed the photo registry and was 

 used to describe details of plant 

 cover not evident on the aerials. 

 Exotic plants such as Melaleuca and 

 Brazilian pepper were largely absent 

 from this tract. Fire has had a se- 

 rious effect on the plants and soils 

 of the tract as evidenced by numerous 

 burnt out hammocks and pine stands. 

 The results of the study are present- 

 ed in Figure 1 and Table 1 which pro- 

 vide a map and list of visually domi- 

 nant plant groupings and also by 

 Figure 2 which subdivides the area 

 according to duration of flooding. 



To interpret Figure 1 , associa- 

 tions or features have been lettered 

 according to the following key: A - 

 Pineland associes; B - Pine barrens; 

 C - Swale with mixed grasses, rushes 



and scrub buttonwood; D - Eleocharis 

 (tall phase) and freshwater man- 

 groves; E - Eleocharis (short phase) 

 and freshwater mangroves; F - Pot- 

 hole ponds; G - Chara ponds; H - But- 

 tonwood hammocks and strands on 

 "Gandy peat" soil; I - West Indian 

 hardwood hammock; J - Cresent Lake; 

 K - Red mangrove berm that experi- 

 ences daily tidal influence; L - Man- 

 grove impoundment and possible weekly 

 tidal; M - Farmland; N - Impacted 

 tidal creek system; - Golf course 

 and airport; P - Lake Marco Shores; 

 Q - Polyhaline mangrove; R - Fresh- 

 water red mangrove forest; S - Black 

 rush (Juncus roemerianus) ; T 

 Fimbristylis-Spartina . 



The present mangrove and emer- 

 gent vegetative associations north of 

 the main east-west levee extension 

 are depositing their leaf, seed and 

 twig fall in situ and this is leading 

 to a rapid elevation of soil pro- 

 files. The Water Surveillance Branch 

 for Region IV of The U.S. Environ- 

 mental Protection Agency (USEPA) , 

 has collected field data on water 

 quality and primary production in 

 this area (Cavinder 1979). In pure 

 Eleocharis stands they found a live 

 standing crop biomass of 295 g/nu 

 (ash free dry weight) with 136 g/m 

 of dead material. The accretion of 

 material within the marsh has been 

 hastened by a heavy growth of Chara 

 in the permanent open ponds. The 

 USEPA and Courtney (1979) have re- 

 ported high rates of respiration 



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