Investigating the Roles of Engineered Wetland
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BUILDING BETTER WETLANDS FOR AMPHIBIANS: INVESTIGATING THE ROLES OF ENGINEERED WETLAND FEATURES AND MOSQUITOFISH (GAMBUSIA AFFINIS) ON AMPHIBIAN ABUNDANCE AND REPRODUCTIVE SUCCESS A Dissertation Presented to The Faculty of the Graduate School At the University of Missouri In Partial Fulfillment Of the Requirements for the Degree Doctor of Philosophy By CHRISTOPHER D. SHULSE Dr. Raymond D. Semlitsch, Dissertation Supervisor MAY 2011 The undersigned, appointed by the dean of the Graduate School, have examined the dissertation entitled BUILDING BETTER WETLANDS FOR AMPHIBIANS: INVESTIGATING THE ROLES OF ENGINEERED WETLAND FEATURES AND MOSQUITOFISH (GAMBUSIA AFFINIS) ON AMPHIBIAN ABUNDANCE AND REPRODUCTIVE SUCCESS Presented by Christopher D. Shulse A candidate for the degree of Doctor of Philosophy And hereby certify that, in their opinion, it is worthy of acceptance. Dr. Raymond D. Semlitsch Dr. James E. Carrel Dr. Lori S. Eggert Dr. Kathleen M. Trauth Dedicated to my wife, Tracy, and my children, Austin and Ashlee, whose love and support have sustained me through my endeavors. ACKNOWLEDGEMENTS I owe a great deal of gratitude to my graduate advisor, Dr. Ray Semlitsch, for his support, advice, and encouragement. I have learned much about amphibian conservation and scientific investigation from Ray; he is a skilled research scientist and devoted mentor to his students. The uplifting statement, “…I’d be lost but for the Grace of God,” has served as a subtle, but ever-present source of inspiration, within every e-mail correspondence from Ray. I thank the Semlitsch Lab, members both past and present, for their advice and encouragement during my infrequent visits to the lab. Although I have been very fortunate to complete my Ph.D. while continuing to work full-time at the Missouri Department of Transportation, one of my greatest regrets is that I have missed out on many stimulating discussions and camaraderie with my fellow lab members. They are a brilliant group of scientists and tomorrow’s leaders in the field of conservation biology. I especially thank Tracy Rittenhouse, Bethany Williams, Bill Peterman, and Julia Earl for statistical advice and for reviewing manuscripts. I thank my committee members, Jim Carrel, Lori Eggert, and Kate Trauth for their support during my time at M.U. I especially thank Dr. Trauth for taking time out of her busy schedule on many occasions to discuss open channel hydraulics. Dr. Frank Thompson provided much appreciated statistical advice during my data analyses for Chapter 2. Nila Emerich was always generous with her assistance, encouragement, and good advice. Tyeece Little and Chris Todd were instrumental in making sure grants were executed smoothly. I owe much appreciation to the dedicated field technicians and laborers who spent many hours in often unpleasant conditions sampling amphibians and invertebrates, ii installing drift fences and pitfall traps, and hauling supplies in and out of research sites. Dana Drake and Andrea Drayer trekked across northern Missouri several times during the summer of 2006 and I could not have asked for a more devoted and knowledgeable team. Lelande Rehard is one of the hardest working, versatile, and most respectful persons that I have met. Lelande worked tirelessly setting up drift fences and pitfall traps, sometimes alone for hours. He is also skilled at amphibian identification and data collection, and he provided much needed assistance with both tasks on multiple occasions. I thank Sarah Becker, Diane Kuschel, and Kathryn Kettenbach who spent many hours in the field collecting data and working on experimental arrays. Many other student laborers, too numerous to name individually, provided assistance for which I am deeply grateful. Multiple employees of the Missouri Department of Conservation (MDC) were essential to the success of this research. James E. (Gene) Gardner was instrumental in coordinating the project from within MDC, gaining access for me and my team to conduct studies on MDC lands, securing Wildlife Diversity Funds, and helping to co- author Chapter 3. Gene is a dedicated conservation professional and he has served as a valued mentor to me for over ten years. Jeff Briggler, MDC herpetologist, is passionate about amphibian conservation and I greatly appreciate his support of my research. John George, Greg Gremaud, and Mike Jones helped me find suitable locations for experimental wetland construction. Many other MDC employees helped with permitting, field maintenance, rotenone applications, and various support roles. Without MDC backing, this project would not have been possible. The support I received from my current employer, the Missouri Department of Transportation (MoDOT), was a vital element of this project. MoDOT provided iii resources including staff, supplies, and equipment to help complete this project; and resources for me to attend multiple conferences both within and outside of Missouri. Steven “Butch” Mundle, allowed me to “go outside of my box” to conduct this research, and his support, trust, and encouragement will always be remembered. The staff of the Environmental Studies Section of MoDOT’s Design Division helped with many aspects, including mitigation site information, locations for experimental wetland construction, and assistance in the field. Gayle Unruh, Buck Brooks, Nate Muenks, Laura Ruman, Melissa Scheperle, John Mehuys, Rob Meade, Alan Leary, and Bree McMurray were always willing to answer questions and provide encouragement. Memebers of MoDOT Management such as Diane Heckemeyer, Kathy Harvey, Kirk Juranas, Paula Gough, and Dave Silvester provided valuable support that allowed this research to move forward. Ernest Perry and the staff or Organizational Results helped me secure MoDOT research funding. Ernie has always enthusiastically supported my efforts to earn a Ph.D., and my various efforts to improve MoDOT processes through research. Most important has been the support and encouragement of my friends and family. My friend Doug Mahsman encouraged me to take a step of faith to begin this journey. That step has paid off. My parents, Mike and Connie, allowed me to catch reptiles and amphibians, and (reluctantly) keep them in my room and in the basement. My wife, Tracy, has also supported my interests and has faithfully stood by me, despite many times when she felt like a single parent, through the rigors of graduate research and my full-time career. I look forward to the rest of our future together. I thank Tracy, and my children, Austin and Ashlee, for their patience, support, and love over the last six years. Without them, the following pages would not have been written. iv TABLE OF CONTENTS Acknowledgements ............................................................................................................. ii List of Tables .................................................................................................................... vii List of Figures .................................................................................................................... ix Abstract ............................................................................................................................. xii Chapter 1. INTRODUCTION .................................................................................................. 1 Literature cited ........................................................................................................ 6 2. INFLUENCES OF DESIGN AND LANDSCAPE PLACEMENT PARAMETERS ON AMPHIBIAN ABUNDANCE IN CONSTRUCTED WETLANDS........................................................................................................... 9 Abstract ................................................................................................................... 9 Introduction ........................................................................................................... 10 Methods................................................................................................................. 13 Results ................................................................................................................... 19 Discussion ............................................................................................................. 25 Acknowledgements ............................................................................................... 31 Literature Cited ..................................................................................................... 32 3. TESTING WETLAND FEATURES TO INCREASE AMPHIBIAN REPRODUCTIVE SUCCESS AND SPECIES RICHNESS FOR MITIGATION AND RESTORATION ................................................................ 51 Abstract ................................................................................................................. 51 Introduction ........................................................................................................... 52 Methods................................................................................................................. 55 Results ................................................................................................................... 61 Discussion ............................................................................................................. 67 v Acknowledgements ............................................................................................... 76 Literature Cited ....................................................................................................