Paleoecological insights on fixed tree island development in the Florida Everglades: I. environmental controls: Chapter 4

By: , and 
Edited by: Fred H. Sklar and A. van der Valk

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Abstract

Palynological and geochemical analyses of sediment cores collected on two tree islands in the Florida Everglades indicate long-term hydrologic and chemical differences between tree islands and surrounding marshes and sloughs. Gumbo Limbo and Nuthouse tree islands are elongate, teardrop-shaped islands in Water Conservation Area 3B. Prior to tree island formation at both sites, pollen records indicate that sites on modern tree island heads were covered with sawgrass marshes with abundant weedy annuals. Such vegetation is characteristic of moderate water depths and hydroperiods with frequent droughts or disturbances. Contemporaneously deposited sediments on tree island tails indicate progressively deeper water conditions with increasing distance from the head; wetlands surrounding tree islands were covered by sloughs with deep water and long hydroperiods. Tree island formation occurred at about 1200 BC on Gumbo Limbo Island, with mature tree island vegetation established by about 800 AD. On Nuthouse Island, tree island formation occurred around 300 AD, shifting to mature tree island vegetation around 1400 AD. Thus, tree island formation began on these islands between 3.2 Ka and 1.7 Ka. Maturation of tree islands took between 1,000 and 2,000 years, and vegetation on these tree islands has been relatively stable for the last 600–1,200 years. Phosphorus levelson tree island heads have been extremely high (approximately six times greaterthan baseline levels in marshes) throughout the history of the sites, and phosphorus content in tree island tails began increasing when tree island formation occurred. Elevated phosphorus content may reflect the long-termpresence of wading birds at these sites and provide a proxy for reconstructing the historic distribution of wading bird populations.

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Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Paleoecological insights on fixed tree island development in the Florida Everglades: I. environmental controls: Chapter 4
DOI 10.1007/978-94-009-0001-1_4
Year Published 2002
Language English
Publisher Springer
Contributing office(s) Coastal and Marine Geology Program
Description 35 p.
Larger Work Type Book
Larger Work Subtype Other Government Series
Larger Work Title Tree islands of the Everglades
First page 117
Last page 151
Country United States
State Florida
Other Geospatial Everglades