Lane, Cynthia , Roncal, Julissa , Wright, Samuel , Maschinski, Joyce .
Environmental gradients and vegetation in a South Florida dune system.
HUMAN development has reduced the dune ecosystem that once framed the south-east coast of Florida to few small fragmented areas. To restore this ecosystem and recover its rare plant species we need information on the environmental characteristics of the gradient associated with distance from the coast and their influence on species composition and abundance. In the summer 2001 and spring 2002, we sampled 72 3 x 8 m plots within 5 transects at Crandon Park on Key Biscayne and 25 plots within 6 transects at South Beach Park in Boca Raton. From each plot we collected composite soil samples from two depths (0-15 cm and 46-61 cm) and organic matter accumulation samples. Sand erosion and accretion, salt spray and total cover of each plant species were also recorded for each plot. We detected a dynamic between areas near the coast and/or on taller dunes where salt spray, pH and sand movement were typically at their highest values, and areas farthest from the coast, and/or on the back sides of dunes where soil moisture, soil nutrients (except K and NH4-N), and organic matter accumulation were greatest. This trend was more pronounced for the samples at the 0-15 cm depth. Species diversity differed across the distance gradient at Crandon only, where the lowest mean number of species per plot (17, S.E. 2.7) was found at 6 m from the tide line and the highest mean number of species per plot (31, S.E. 4.8) at 84 m. However, at South Beach, regression analysis showed that an increase in woody cover (>2 m tall) had an effect on species number per plot. Since environmental and vegetation characteristics varied between sites, we suggest that restoration planning should be site specific.
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South Florida plant species and habitat conservation at Fairchild
1 - Ecological Strategies, P.O. Box 3, Maiden Rock, Wisconsin, 54750, USA
2 - Fairchild Tropical Botanic Garden, Center for Tropical Plant Conservation, 11935 Old Cutler Road, Coral Gables, Miami, Florida, 33156-4242, USA
sand erosion and accretion
organic matter accumulation.
Presentation Type: Poster:Posters for Sections
Location: Auditorium/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 12:30 PM