Forest Decision Making Under Uncertainty: Adaptive
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FOREST DECISION MAKING UNDER UNCERTAINTY: ADAPTIVE MANAGEMENT FOR THE CONSERVATION OF BIRD POPULATIONS ON A NATIONAL WILDLIFE REFUGE by CLINTON THOMAS MOORE (Under the direction of Michael J. Conroy) ABSTRACT I constructed a stochastic, spatially-explicit landscape model to seek optimal forest management decisions for long-term persistence of populations of red-cockaded woodpecker (Picoides borealis) and wood thrush (Hylocichla mustelina) on the Piedmont National Wildlife Refuge in Georgia, USA. I addressed uncertainty in decision making by considering alternative model forms that expressed different mechanisms of response by the forest and the bird populations to silvicultural actions. The implication of model uncertainty in this system is that conservation tradeoffs for both species differ according to choice of model. Decision variables in each model were the spatial scheduling of forest compartments for silvicultural treatments and the average periodicity of prescribed burning in compartments. Model responses were the number of active woodpecker clusters and abundance of wood thrushes. Additionally, I obtained a composite response as the average of the two abundance responses, each scaled by its standard error. I simulated each model under extremes of the decision alternatives, and I found a near- optimal management schedule for each model and for each of the responses. I also found near-optimal schedules for the case of complete uncertainty with regard to all models in the model set. Forest and bird monitoring data collected on the Refuge are the means by which measures of belief in each model are updated and decisions are adaptively improved. In nearly all models, both species responded strongly, but in opposite directions, to burning, and woodpeckers were sensitive to compartment scheduling. Consequently, optimal decisions were mostly similar among models, and values of information computed for each response suggested that little would be gained in management performance by resolving uncertainty among these models. However, fundamental uncertainties in the management of this system were probably not captured in this model set, and adaptive approaches therefore still hold promise for Refuge management. Current impediments to conducting adaptive management on the Refuge are (1) uncertainties regarding objectives, (2) lack of a comprehensive forest monitoring system, (3) inadequate system models, and (4) constraints in the expression and breadth of decision alternatives. I discuss critical information needed for the adaptive management of this and similar resource systems. INDEX WORDS: Adaptive management, Birds, Conservation, Decision making, Dynamic model, Endangered species, Forest management, Georgia, Habitat model, Hylocichla mustelina, Monitoring, Multiple species management, Optimization, Picoides borealis, Piedmont National Wildlife Refuge, Population model, Red-cockaded woodpecker, Silviculture, Simulation, Spatially-explicit model, Uncertainty, Wood thrush FOREST DECISION MAKING UNDER UNCERTAINTY: ADAPTIVE MANAGEMENT FOR THE CONSERVATION OF BIRD POPULATIONS ON A NATIONAL WILDLIFE REFUGE by CLINTON THOMAS MOORE B.S.F.R., The University of Georgia, 1982 M.Stat., North Carolina State University, 1986 A Dissertation Submitted to the Graduate Faculty of The University of Georgia in Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY ATHENS, GEORGIA 2002 © 2002 Clinton Thomas Moore All Rights Reserved FOREST DECISION MAKING UNDER UNCERTAINTY: ADAPTIVE MANAGEMENT FOR THE CONSERVATION OF BIRD POPULATIONS ON A NATIONAL WILDLIFE REFUGE by CLINTON THOMAS MOORE Approved: Major Professor: Michael J. Conroy Committee: Robert J. Cooper Richard F. Daniels James T. Peterson H. Ronald Pulliam Electronic Version Approved: Gordhan L. Patel Dean of the Graduate School The University of Georgia May 2002 DEDICATION I dedicate this work to Joan and Truman, who instilled in me a love for inquiry and for the natural world; to Scott and Timothy, who I hope will one day inherit, perhaps in small part by my contributions, a planet more mindful of its ecological capacity; and to Mary, who shares her strength, wisdom, and optimism with me each day. iv ACKNOWLEDGMENTS This work would not have been possible without the help of many individuals and benefactors. I thank faculty members Bruce Beck, Robert Cooper, Richard Daniels (University of Georgia Warnell School of Forest Resources), and Ronald Pulliam (University of Georgia Institute of Ecology) for their review of my proposal and their helpful input into my research. Kevin Boston (Carter Holt Harvey Forests, New Zealand) supplied me background information and advice on heuristic and classical optimization procedures, and he provided me a much-needed introduction to geographic information systems. James Peterson’s (U.S. Geological Survey, Georgia Cooperative Fish and Wildlife Research Unit, Warnell School of Forest Resources) work with Bayesian belief networks gave me another perspective on making resource decisions under uncertainty. Bruce Lubow (U.S. Geological Survey, Colorado Cooperative Fish and Wildlife Research Unit) provided comments and suggestions regarding model optimization under program ASDP. Roger Lowe (Warnell School of Forest Resources) provided substantial assistance in the development of digital maps and the spatial database. I received invaluable assistance from personnel at the Piedmont National Wildlife Refuge. In particular, I would like to thank Dean Metteaeur, John Mason, and Greg Walmsley for technical assistance and information, and Ronnie Shell and Carolyn Johnson for their enlightening discussions on Refuge management. v vi My student colleagues, Carole Anderson, Laura Dawood, and Larkin Powell, collected much of the data used in my models, and they offered me vital insight on sampling procedures, Refuge management practices, and the general nature of the Refuge. I extend special thanks to colleague Todd Plummer, who worked tirelessly and unselfishly to provide me with data and estimates that made my modeling efforts possible, and who provided comic relief in the darkest hours of project report preparation. Funding for my research came from the U.S. Environmental Protection Agency STAR Fellowship Program, from the University of Georgia University-Wide Assistantship Program, and from a teaching assistantship provided by the Warnell School of Forest Resources. I also received assistantship and travel support from the Georgia Cooperative Fish and Wildlife Research Unit through a project (Research Work Order 34) funded by the U.S. Geological Survey Cooperative Research Units Center and the U.S. Fish and Wildlife Service, Region 4. The University of Georgia Stoddard-Burleigh- Sutton Award defrayed costs of books and supplies. I am indebted to my employer, the U.S. Geological Survey Patuxent Wildlife Research Center, which supported the final months of my research. William Kendall (Patuxent Wildlife Research Center) sponsored travel to meetings where I presented intermediate results of my research. Sue Anthony and Diane Pritchett (Georgia Cooperative Fish and Wildlife Research Center), two of the most affable, competent professionals with whom I have ever had the pleasure to work, handled the overwhelming details of my funding and plucked me from the administrative flames several times. vii I thank my advisor, Michael Conroy (Georgia Cooperative Fish and Wildlife Research Unit, Warnell School of Forest Resources), who provided guidance and served as a valued mentor throughout this difficult project. His advice, both technical and nontechnical, helped me to navigate around a seemingly unending series of obstacles. He worked on my behalf to secure the financial support I needed, and I am grateful for the professional development opportunities he provided me. Leaving a comfortable professional job, moving my family, and adjusting to life as a “nontraditional” student (I was twice the age of my first classmates in 1997) was personally anguishing for me, and I might have never come through the ordeal without the many friends and family members who offered their support and encouragement. The Bruggink, Kendall, and Querin families kept the lines of communication open and were always there to hear my tired sob stories. The 402 Lab (“Commiseration Central”) hosted a number of mood-altering discussions with Matt, Jennifer, Todd, Nathan, Craig, Kim, Chris, Jay, Carole, Tom, and other colorful Warnell characters. My family, immediate and extended, made sure that I was included in birthday celebrations, beach trips, and reunions, and they were understanding on the many occasions that my work prevented my participation. My parents, Joan and Truman Moore, were always there for my family when my travel schedule or other work requirements left the kids without care. Though my parents have been eager to see me finish, they never demonstrated impatience with the slow pace of my work and have only inquired how they could help. I watched my children, Scott and Timothy, grow from their pre-K’s into their pre- teens over the course of my study. As they have matured, they too have shown extraordinary patience and understanding in the demands of my class work and research. viii I thank them for the time they have given me, and I look forward to being more preoccupied with board games, camping, movies, and baseball. My last but deepest expression of gratitude goes to my wife, Mary, who made my program of study possible. Mary maintained the house, nurtured the kids,