Bulletins of American paleontology (Bull. Am. paleontol.) Vol 361

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TTtF 'BuiOtins of icmtoi Begun in 1895 NUMBER 361 NOVEMBER 28, 2001 Paleoecological Studies of South Forida edited by Bruce R Wardlaw Published in cooperation with The United States Geological Survey ^USGS science lor a changing world Paleontological Research Institution 1259 Trumansburg Road New York, 14850 U.S.A Ithaca, PALEONTOLOGICAL RESEARCH INSTITUTION Officers Christopher G Maples John Pojeta, Jr Prksident First Vice-President Howard Second Vice-President Secretary P Hartnett Shirley K Egan Patricia A Johnson Treasurer Director Warren D Allmon Trustees John D Allen Carlton E Brett William L Crepet W Michael Driscoll J Thomas Ddtro, Jr P.^tricia Haugen Robert M Horn, Harry G Lee Amy R Proujansky Mecjan D Shay Mary M Shuford Constance M Soja John C Steinmetz Peter B Stifel Sally T True Philip Jr Arthur Waterman McCune Trustees Emeritus Harry A Leffingwell Robert M Linsley Samuel T Pees Edward B Picou, Jr James E Sorauf Raymond Van Houtte William P Thomas Ventress Whiteley S E BULLETINS OF AMERICAN PALEONTOLOGY and PALAEONTOGRAPHICA AMERICANA Warren Editor D .Allmon A list of titles in both series, and available nuinbers and volumes may be had on request Volumes 1-23 oi Bulletins ofAmerican Paleontology are available from Periodicals Service Company, 11 Main St., Germantown, New York 12526 USA Volume ! of Palaeontographica Americana has been reprinted by Johnson Repnnt Corporation, 1 Fifth Ave., New York, NY 10003 USA Subscriptions to Bulletins of American Paleontology are available for US $150 per year (individual or institution) plus postage Issues are available and priced individually Numbers of Palaeontographica Americana for additional information, vv-rite are priced individually or call: Paleontological Research Institution 1259 Trumansburg Road Ithaca, NY 14850 USA (607) 273-6623 FAX (607) 273-6620 www.priweb.org @ This paper meets the requirements of ANSi/NISO Z39.48-1992 (Permanence of Paper) yaUcmtipoicqs) Begun in 1895 NUMBER 361 NOVEMBER 28, 2001 Paleoecological Studies of South Forida edited by Bruce R Wardlaw Published in cooperation with The United States Geological Survey ^USGS science for a changing world Paleontological Research Institution 1259 Trumansburg Road New York, 14850 U.S.A Ithaca, ISSN 0007-5779 ISBN 0-87710-453-0 Library of Congress Control Number: 2001-135296 Note: Beginning with issue number 356, Bulletins of American Paleontology is no longer designating volumes The journal will continue to publish approximately 2-4 issues per year, each of which will continue to be individually numbered Printed in the United States of America Allen Press, Inc Lawrence, KS 66044 U.S.A CONTENTS Page Chapter I Introduction to Paleoecological Studies of South Florida and the ImpUcations for Land Management Decisions Bruce R Wardlaw Chapter The Relationship between Stable Isotopic Variations (O, H, and C) and Salinity in Waters and Corals from Environments in South Reading the Paleoenvironmental Record Peter K Swart Rene M Price, and Lisa Greer Florida: Implications for 17 Chapter Sediment Dynamics of Florida Bay Mud Banks on a Decadal Time Scale Charles W Holmes, John Robbins, Robert Halley, Michael Bothner, Marilyn Ten Brink, and Marci Marot 31 Chapter The Florida Everglades Ecosystem: Climatic and Anthropogenic Impacts Over Debra A Willard Charles W Holmes, and Lisa M Weimer the Last Two Millennia 41 Chapter Hydrology, Vegetation, and Climate Change in the Southern Everglades During the Holocene Marjorie Green Winkler Patricia R Sanford and Samantha W Kaplan 57 Chapter A Pollen Zonation of Southwestern Florida Using Multivariate Statistical Methods and its Application to Two Vertical Sedimentary Sequences M.A O'Neal LP 101 Tedesco C Souch and J.F Pachut Chapter A Century of Environmental Variability in Oyster Bay Using Ostracode Ecological and Isotopic Data as Paleoenvironmental Tools Carlos A Alvarez Zarikian, Peter K Swart Terri Hood Pat L Blackwelder Terry A Nelsen and Chades Featherstone 133 Chapter Diatoms J.K as Indicators of Huvane and S.R Environmental Change in Sediment Cores from Northeastern Florida Bay 145 Cooper Chapter Historical Trends in Epiphytal Ostracodes TM from Florida Bay: Implications for Seagrass and Macro-benthic Algal Variability Cronin C.W Holmes G.L Brewster-Wingard S.E Ishman H.J Dowsett D Keyser, and N Waibel 159 Chapter 10 MoUuscan Faunal Distribution in Florida Bay, Past and Present: An Integration of Down-core and Modern Data G Lynn Brewster-Wingard, Jeffery R Stone, and Charles W Holmes Chapter 199 Ecological Controls on Benthic Foraminifer Distributions in Biscayne Bay Florida Scott E 233 Ishman Chapter 12 Ostracode Shell Chemistry as a Paleosalinity Proxy Gary Index S Dwyer and Thomas M Cronin in Florida Bay 249 277 CHAPTER INTRODUCTION TO PALEOECOLOGICAL STUDIES OF SOUTH FLORIDA AND THE IMPLICATIONS FOR LAND MANAGEMENT DECISIONS Bruce U 926A Geological Survey, S R Wardlaw National Center, Reston, Virginia 20192 ABSTRACT The Florida Everglades developed from the last two millennia is the interplay of sea level and climate The subtle balance of these two factors over important to understanding restoration strategies During the Medieval Age the Everglades showed a general drying precipitation while sea level was rising The Little the slowing in the relative rate of sea level rise This failure to keep base water flow modeling Land use and water management practices over the in its ability to Salinity in Florida Bay lO" century by intense is last century have greatly partitioned the Everglades, affected by marine circulation, climate (rainfall) and runoff Marine circulation railroad, in the 1900"s and has slowly been decoupled throughout the last century, especially after 1970 rainfall and runoff again Salinity in central, A western and southern (Atlantic transitional) zones and eastern zones Salinity can be predicted for specific sites in Florida is influenced by direct rainfall; influenced to a large extent by runoff These latter zones need to Bay following known INTRODUCTION The South Florida ecosystem has undergone dynam- fill this last century but most of these are analogy Can paleoecological studies important information gap? Yes, detailed pa- leoecological studies provide the retrospective infor- mation to understand the course and cause of these changes Can this information influence and be utilized by decision makers? Yes, more coherent policies scientific this information enables a foundation on which to base and decisions This volume offers a wide variety of paleoecological studies in many different areas of South Florida The area of study and the techniques utilized affect the conclusions which vary from local and qualitative to widespread and quantitative The underlying data for interpretation are invaluable Swart et al (Chapter 2) show by the isotopic sig- nature of the water that salinity in central, western and southern (Atlantic transitional) zones of Florida Bay is influenced by direct rainfall; salinity in the northern (northern transitional) and eastern zones of Florida is influenced to a large extent by runoff (Text-fig Holmes et al in dating cores (Chapter 3) discuss the from the in the early restoration goal should be to is be monitored to ascertain that rainfall and runoff are indeed coupled to the degree that they have been changes over the was reduced highway, and bridge construction connecting the Keys Rainfall and runoff appeared coupled early couple known only by and peat accumulation, century and should be considered last respond ecosystem-wide in predictable ways to climate and sea level change salinity in the northern (northern transitional) ic Period and the Little Ice level with Everglades sediment yielded shorter hydroperiods and dryer conditions Sea level has been steadily rising over the compounding Warm The Medieval Warm Period trend was due to a significant decrease in annual Ice Age trend was due to the combined effect of reduced precipitation and trend mud banks utility Bay ) of -'"Pb of Florida Bay This technique provides age models for the last 150 in the past months rainfall years and is variability and change critical for unraveling the sequence of in Florida In the peats of the terrestrial of the initial transgression in the bays, radiocarbon dates provide the age until Bay ecosystem and the peats framework and are reliable up near modern time where the margin of error ex- ceeds the age value -'"Pb has provided reasonable age models in the uppermost part of the peats for the last century of deposition Willard et al (Chapter 4) utilize modem census data from the ridge and slough and southeastern Everglades National Park along with that data collected by Riegel (1965) to develop a robust modem analogue for interpreting down-core terrestrial samples Core samples are from the northern ridge and slough, Shark River Slough, and Taylor Slough The core data indicate that the Everglades were generally wetter (experienced deeper water and longer hydroperiods) than today, but experienced three significant drying spells: one that correlates with the Medieval Warm Period (800-1400 AD): one that correlates with the Little Ice Age (15501850 AD): and one that is the present century The present dry spell shows a progressive deterioration with shallower water and shorter hydroperiods by 1930, significant localization of the marsh in the 1950"s and 1960"s, and expansion of cattail marshes at nutrient-enriched sites after 1960 Bulletin 361 Introduction: years ago by a widespread climate change; however, based on their data, it is more easily explained as part of the Holocene transgression (see below) They cau- Radiocarbon Ages of Initial Sedimentation In Wardlaw years before present tion that dating at close intervals is critical standing the ecosystem history, yet precision when to under- prey to lack of their correlation of marls as contemfall poraneous is not supported by their sparse age data However, based on diatom abundances, they propose a wet period between 2,000 and 1,600 years B P., Elevation of Bedrock Surface Stiowing Everglades Trough (Shaded) Contours in feet above mean sea Text-figure — Basal ages of initial level Everglades transgressive sed- imentation moditied from data presented in Winkler et al (this vol- ume) and elevation of bedrock surface modified from Brooks 1984) ( outlining Everglades trough (shaded, elevations generally above mean sea Text-figure level) — Vegetation types (modified from Willard et al 2001 ( ft or less which agrees with the wet period observed by Willard et al (Chapter 4) based on pollen at the base of their sections (0 to 800 AD) O'Neal et al (Chapter 6) utilize census data from Riegel (1965) which concentrated on the western portion of Everglades National Park Numerical analysis (cluster and multivariate analysis) characterize spatial pollen zones of the western Everglades and examine the historical record in two cores from the mangrove swamps of the same region They document the overall late Holocene transgression and differentiate mangrove swamp communities as coastlines that first transgressed and then were stabilized Zarikian et Aj of South Florida (modified from Willard ) al (Chapter 7) show that rainfall is the dominant driving force behind long-term variability in microfaunal assemblages from one core from Oyster Bay within the mangrove forests This environment (interior mangrove forest) generally is most susceptibile to hurricane devastation and yet the core provides et al., this volume) and soil types (B) of parts of South Florida Bulletin 361 Weedy Sawgrass Marsh Cattails Site \ Site Site / \ Site Wet Prairie / Site Site 2000- Site? Site Mangrove Mangrove Mixed Drier 1800 Si Slough ^ Drier Drier Slough Slough 1600 Mixed Disturbed Slough and Fresh Water Marsh Brackish Slough Slough Influence Wet 1200 I, and Fresh Water Marsh Bracl Mosaic T3 800 HI Sawgrass Marsh Wet and Sawgrass Marsh Prairie and Sawgrass Marsh and Sawgrass Marsh Slough 600 Wet Prairie 400 - Slough Slough Slough 200 0- Year o_ Text-figure —Pollen wetland subenvironments in inset (modified from data in Willard et al this Bay indicated for eight peat cores from South Florida over the past millennia Locality correlation to hurricane events, though the au- dominance and thors maintain they remain an important factor Stable habitat, salinity, little isotopes from ostracode and foram tests suggest a de- coupling of rainfall and freshwater flow during the 1970's for this particular location Huvane and Cooper (Chapter 8) show that diatoms common to Florida Bay cores and useful in sea- are grass, salinity, Cronin and productivity studies et al (chapter 9) utilizing show ostracode-epiphyte and macro-benthic algae fluctuate in abundance and coverage They were sparse in the late 19* and early 20"" centuries, dense in the 1950's and 1960's and declined in the 1970's and 1980"s; but they are still more common than at the turn of the 20* century distributions that seagrass Brewster- Wingard et al shown volume) diversity track the changes in local and water quality through time Ishman (Chapter 1 ) recognizes four distinct foraminiferal assemblages in Biscayne Bay: an open-bay seagrass, an open-bay substrate, a restricted and a high productivity assemblage The restricted assemblage represents reduced salinity, restricted circulation, and point-source fresh water input The high productivity assemblage represents high nutrient input and is very local in the northern part of the Bay Dwyer and Cronin (Chapter ratios from adult ostracode show that Mg/Ca and provide a reasonable value function; they conclude that there is a strong climatic control on Florida Bay salinity THE EVERGLADES (Chapter 10) show that the molluscan faunas that occur throughout the cores basically reflect the same fauna that is present at those sites today However, subtle fluctuations in patterns of 12) shells reflect the salinity Data presented in this volume suggest that the Ev- erglades are the result of a delicate balance of sea level rise and climate (precipitation) Comparison of the age Bulletin 361 266 Table Depth (cm) —Continued Year Genus Species Molt OsTRACODE Shell Chemistry: Dwyer and Cronin Table Depth (cm) —Continued Year Genus Species Moll 167 Bulletin 361 268 Table Depth (cm) 115 115 113 113 107 107 0? 103 103 103 101 101 99 99 97 97 97 95 95 93 93 91 91 89 89 89 87 85 83 83 83 81 81 81 79 79 79 77 77 75 75 75 73 73 73 71 71 67 67 63 61 61 55 53 53 51 —Continued Year Genus P Species Molt VPI Mi;/Ca Sr/Ca N;i/Ca Mg/Ca Sr/Ca Na/Ca (avg.) (avg.) (avg.) OsTRACODE Shell Chemistry: Dwyer and Cronin 60 50 CO O40 CD 30 20 269 Bulletin 361 270 Bank Core 19B Russell Mg/Ca Na/Ca Sr/Ca (avg) (avg) (avg) Park Key Core 23A Mg/Ca 15 20 25 30 (avg) 35 40 45 50 Sr/Ca (avg) Na/Ca (avg) Sr/Ca (avg) Na/Ca (avg) 3.0 0- 10- 20301, 40- g-50- 60708090- Bob Allen Core 6C Mg/Ca 15 20 25 0- I 30 I (avg) 35 40 45 50 _L I I 3.0 0- I O 20- 20- 40- 40- 60- -g- 60- -£ 3.5 , ] 4.0 4.5 I £Q a '^ 100-1 °iooH 120- 120 140160-J Text-figure 80-
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