HR: 11:20h
AN: PP12A-05    [Abstracts]
TI: Vegetation Response to ENSO-tied Precipitation and Human Induced Hydrological Changes in the Fakahatchee Strand Preserve State Park, Florida
AU: * Donders, T H
EM: t.h.donders@bio.uu.nl
AF: Department of Palaeoecology, Laboratory of Palaeobotany and Palynology, Utrecht University Budapestlaan 4, Utrecht, 3584 CD Netherlands
AU: Wagner, F
EM: r.wagner@bio.uu.nl
AF: Department of Palaeoecology, Laboratory of Palaeobotany and Palynology, Utrecht University Budapestlaan 4, Utrecht, 3584 CD Netherlands
AU: Visscher, H
EM: h.visscher@bio.uu.nl
AF: Department of Palaeoecology, Laboratory of Palaeobotany and Palynology, Utrecht University Budapestlaan 4, Utrecht, 3584 CD Netherlands
AB: In southern Florida wetlands, hydrological factors control the composition and growth conditions of the vegetation. The amount of winter precipitation, which is strongly linked to the El Ni\~{n}o - Southern Oscillation (ENSO) system, determines water availability during the growth period. The low topography creates an integrated wetland system were local hydrological conditions follow regional patterns. The high water-sensitivity, ENSO teleconnection and low topography make the southern Florida wetlands highly suitable for climate variability studies. Peat sequences accumulated in {\it Taxodium} old growth stands from the Fakahatchee Strand Preserve State Park provide an unique natural archive for studying paleo-precipitation changes by means of pollen-, leaf macro remain- and tree-ring analysis. In annual-resolved studies spanning the 20th century all proxies indicate significant responses of the wetland vegetation to the hydrological changes provoked by urban development and drainage activities. Superimposed natural dynamics reveal changes in pollen production rates, leaf- and wood-growth parameters, indicative for high frequency El Ni\~{n}o - La Ni\~{n}a dynamics. The information gathered by studying the response range of the FSPSP wetland to environmental perturbations is used for interpretation of a 5ka paleo-vegetation record from the same locality. Changes in vegetation units document the long-term shifts in regional hydrological conditions and point to significant variability in the system during the early part of the record. These variations are likely caused by short regional wet phases and, through the strong ENSO teleconnections, are of prime importance to past climate studies.
DE: 3344 Paleoclimatology
DE: 4522 El Ni¤o
DE: 1803 Anthropogenic effects
DE: 1851 Plant ecology
DE: 1854 Precipitation (3354)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2004 AGU Fall Meeting