Forgotten Grasslands of the South Forgotten Grasslands of the South: Natural History and Conservation Reed F. Noss With a foreword by Edward O. Wilson Washington | Covelo | London Copyright © 2013 Island Press All rights reserved under International and Pan-American Copyright Conventions. No part of this book may be reproduced in any form or by any means without permission in writing from the pub- lisher: Island Press, 1718 Connecticut Avenue NW, Suite 300, Washington, DC 20009 ISLAND PRESS is a trademark of The Center for Resource Economics. Library of Congress Cataloging-in-Publication Data Noss, Reed F. Forgotten grasslands of the South : natural history and conservation / Reed F. Noss ; with a fore- word by Edward O. Wilson. pages cm Includes bibliographical references and index. ISBN-13: 978-1-59726-488-4 (cloth : alk. paper) ISBN-10: 1-59726-488-1 (cloth : alk. paper) ISBN-13: 978-1-59726-489-1 (pbk. : alk. paper) ISBN-10: 1-59726-489-X (pbk. : alk. paper) 1. Natural history--Southern States. 2. Grassland conservation--Southern States. 3. Grassland ecology--Southern States. I. Title. QH104.5.S59N67 2013 508.75--dc23 2012027923 Printed on recycled, acid-free paper Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 Key words: Island Press, grasslands, savannas, pine savannas, woodlands, barrens, glades, outcrops, grassy balds, biodiversity, biological diversity, endemism, endemic, disjunct, species richness, species diversity, southeastern United States, the South, climate change, sea-level rise, paleoecology, community ecology, landscape ecology, conservation, conservation biology, fire Dedication To my grandfather John Burlin Johnson, dean of American metallurgy and amateur dendrologist, who taught me the trees of Ohio and served as my scientist role model. To the state natural heritage programs, the last bastions of natural history –based conservation; to NatureServe, the umbrella organization for these programs; and to Bob Jenkins, the brilliant originator of the natural heritage methodology, while serving as vice-president for science for The Nature Conservancy during many of the organization’s most effective years. Contents Foreword / xi Edward O. Wilson Preface / xiii Acknowledgments / xvii Chapter 1: Natural History of a Forgotten American Grassland / 1 Natural History for Conservation / 4 Grasslands in the South? / 6 What and Where Are Southern Grasslands? / 12 The Grasslands Considered in This Book / 18 Joshua Creek / 26 Chapter 2: Origin and History / 33 A General Model / 34 Geology, Physiography, and Pre-Neogene History / 40 Neogene and Quaternary History / 44 Disjunctions and the Gulf Coastal Corridor / 55 Human History in the South, as It Relates to Grasslands / 61 Mills Creek / 69 Chapter 3: Biological Hotspots and Endangered Ecosystems / 73 Discovering Lost Worlds / 73 Endemism / 77 Centers of Endemism in the South / 84 Peripherals and Disjuncts / 88 Species Richness / 91 Species Richness in Southern Grasslands / 94 People Care about Diversity, Endemism, and Disjunctions / 106 The Decline of Southern Grasslands / 109 ix x Contents Chapter 4: Physical Factors: Rock, Soil, Landform, Water, and Wind / 117 The Purpose of My Journeys / 119 Rock, Soil, and Landform / 121 Water / 168 Wind, Storms, and Sea-Level Rise / 175 Chapter 5: Fire, Big Animals, and Interactions / 181 Bottom-Up, Top-Down, and Sideways / 182 Fire / 192 Herbivores / 212 Interaction of Fire and Hydrology / 228 The Enigmatic Canebrakes / 234 Chapter 6. The Future of Southern Grasslands: Outline of a Strategy / 239 A Conservation Strategy for Southern Grasslands / 242 Examples of Restoration Projects / 257 The Future? / 261 Species List / 267 Literature Cited / 279 About the Author / 303 Index / 305 Foreword Reed Noss’ excellent book took me home to the rich ecosystems to which I was imprinted as a young naturalist. The grasslands of the South, and in par- ticular the Southeast, encompass a diversity of open habitats that beggar the more familiar iconic grasslands of the Great Plains. They are also far richer in species of plants and animals. In fact, acre by acre the Southern Grassland Biome, when it is properly defined to include the longleaf pine savanna and its intermittent hardwood bottomlands, is probably the richest terrestrial biome in all of North America. It is not unusual to find more than two hundred spe- cies of herbaceous plants per acre in the ground flora of the longleaf savanna, and the pitcher-plant bogs, with as many as fifty species of thin-stemmed and crowded herbaceous species per square meter, possibly hold the record for small- scale biodiversity in the world. In addition, more species of amphibians and reptiles occur in the Southern Grassland Biome than any other region of North America. The central Gulf Coast region, if we include the rivers and streams, have per unit area the largest number of turtle species in the world. The South is also one of the least explored major areas of North America. Although the Great Smoky Mountains National Park is largely forested, a tally of the biodiversity by its ongoing All Taxa Biodiversity Inventory (ATBI) gives a hint of what awaits when similar intensive studies are conducted elsewhere in the South: 60,000–80,000 species of plants and animals estimated to be present, of which to date 3,000 are new records for the park and more than 900 are entirely new to science. xi xii Foreword Around the world, grasslands, savannas, and dry tropical forests are the most rapidly disappearing major habitats, their loss due chiefly to the ease with which they are converted into agricultural fields and rangelands. The Ameri- can South is no exception. The longleaf pine savanna, which once covered 60 percent of the South, has been almost entirely cut over for timber extraction. Fortunately, the ground flora, where not replaced by cultivation (including tree farms), is for the most part intact. To understand, cherish, and preserve the great natural heritage of the Southern Grassland Biome should be a priority goal in America’s environmen- tal movement. Reed Noss’ book provides a valuable map to that end. Edward O. Wilson Harvard University Preface People in the South don’t read. That’s a slight exaggeration of what Barbara Dean, my friend and editor at Island Press, informed me when I approached her with a proposal for this book. Barbara’s point was that I must try to make a book on southern grasslands appealing to a geographically broad audience, because surveys show that people in the southern states buy and read fewer books than in any other region of the United States. Indeed, I’ve known south- erners who grew up in homes where the only book was the Bible. Based on attitudes toward scientific topics such as evolution and climate change, many southerners appear to believe that little, if any, reliable knowledge has emerged since biblical times. People in every region are full of superstitions, irrational beliefs, and contradictions. In North America these seem to reach an apogee in the South, because this is where fundamentalist Christianity is most prevalent, and education about ecology and evolution evidently most lacking. But the South is full of ironies. Some of the smartest, friendliest, most generous, most irreverent, politically incorrect, bawdy, and hilarious people I have ever met are southerners. Such contrasts make the South an interesting place to live. Despite my conflicted feelings toward southern culture, I have always wanted to live here—at least for a good part of the year. Not least among the attractions is the weather. The North is just too cold for too long. As a kid in Ohio (just thirty-five miles north of the Kentucky line, where the cultural South begins, as I feel compelled to inform my southern friends), I always said, “When I grow up, I’m going to live someplace warm.” During our family’s xiii xiv Preface annual winter or spring trips to Florida, the brilliance of the sun made me feel happier. My sinus infections disappeared. I delighted in spending the long days catching lizards, exploring the “jungles” in vacant lots between motels, and swimming in the ocean. I was proud to learn that my great-grandparents moved to Sarasota, Florida, back in 1910. Although they lived here for only a portion of each year and ultimately ended up losing their property in the Wall Street crash of 1929 and moving back north, this family history makes me feel almost a legitimate southerner. As I grew up, I kept my eyes southward, look- ing for opportunities. The South ultimately drew me to graduate school at the University of Tennessee–Knoxville and later to the University of Florida in Gainesville. Especially at the latter, I discovered a wonderful thing about the Deep South—you can do field work all year long, and in relative comfort! We have no highly constrained “field season” that confines to the office our wretched colleagues up north. In the South, there is always an excuse to be out of the office. It is a wonder we accomplish anything. It was during my graduate studies, especially the class field trips and regu- lar jaunts with friends through the mountains, gorges, swamps, pine savannas, hammocks (hardwood forests), and seashores of the South, that one of the great empirical generalizations of biogeography came home to me—there are so many more kinds of macroscopic animals and plants down here than in the North. And so much of the diversity in the South is contributed by endemic species, each distributed over a relatively small area. Within the United States, only California might surpass the South as a hotspot of species richness and endemism (this is not known for certain, given the incomplete tally of organisms). In the South you can visit a single site and find species of plants that are known only from those two hundred acres or so, or perhaps from just a handful of other sites.