Copyright by Jonathan Ogren 2008 Conservation Planning in Central Texas by Jonathan Ogren, B.A. Thesis Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Masters of Arts The University of Texas at Austin May 2008 Conservation Planning in Central Texas Approved by Supervising Committee: Robin W. Doughty, Co-supervisor Kenneth R. Young, Co-supervisor Dedication To Crescent and Simon Acknowledgements Much thanks goes to the many people who helped bring this project to completion. My advisor’s Robin Doughty and Ken Young tirelessly evaluated the quality of the work and the clarity of the writing. Their supervision made this project a profound learning experience on a number of levels. Generous financial support came from a two-year fellowship through The Environmental Protection Agency’s National Network for Environmental Management Studies under the supervision of John Johnston. Additional support in the form of a well equipped, comfortable place to work, flexible hours, and insightful information about open space was supplied by Don Bosse. Many people contributed information and support including: Debbie Benesh, Sinclair Black, David Braun, Kent Butler, Bill Carr, George Coffer, David Diamond, Jeff Francel, Trevon Fuller, Justin Garson, Alan Glen, Frank Heitmuller, Clif Ladd, Flo Oxley, Lars Pomara, Jackie Poole, Jose Portillo, Dana Price, Chuck Sexton, Jason Spangler, and Fritz Steiner. Laura Smith, Sheri Russell, and Crescent, Simon, Linda, and Dennis Ogren offered general support and motivation. E.O.Wilson, Rachel Carson, Sam Beam, and David Orr provided inspirational words and writings. May 2008 v Abstract Conservation Planning in Central Texas Jonathan Ogren, M.A., The University of Texas at Austin, 2008 Co-supervisors: Robin Doughty and Ken Young Biodiversity and ecological functionality are being lost rapidly due to human transformation of the environment around the planet. Lands dedicated to conservation of biodiversity and ecological functionality play a key role in mitigating and reversing these losses. This study looks at how conservation planning practices can be integrated into an urban-rural area with numerous conservation needs, heterogeneous environments, and rapidly expanding human populations. The study area consists of the five counties in Central Texas surrounding the City of Austin that are being evaluated for land use by the Envision Central Texas project. Conservation tools used are: 1) environmental space graphs and 2) systematic conservation planning. Environmental space graphs are a straightforward, qualitative visualization tool to analyze the relationships of environmental variables, biodiversity records, existing open space, and proposed conservation lands. Systematic conservation planning used complementarity, .a step-wise process, to select prioritization areas. Selection was based on the occurrence of conservation elements in the following categories: species, species assemblages, topography, soils, geology, weather, critical water quality areas, Edwards Aquifer zones, watersheds, and vulnerability. Forty prioritization runs, each varying the importance of different conservation elements, showed a spectrum of conservation scenarios for Central Texas. Prioritization results were evaluated based on their representation of biodiversity and environmental variables, the total size of the prioritized areas, feasibility, the use of lexical order in the selection process, and irreplaceability—the repeated occurrence of an area in multiple prioritizations. The actual process of systematic conservation planning was evaluated for its usability within the study area and with available data types. vi Table of Contents List of Tables................................................................................................................................................ ix List of Figures ............................................................................................................................................... x CHAPTER 1: INTRODUCTION.................................................................................... 1 The Global Problem of Land Transformation............................................................................................ 1 Conservation as part of the solution........................................................................................................... 1 Conservation Planning Techniques............................................................................................................ 3 Central Texas............................................................................................................................................. 5 This Study: Conservation Planning in Central Texas ................................................................................ 6 CHAPTER 2: REVIEW OF SYSTEMATIC CONSERVATION PLANNING AND ASSOCIATED DISCIPLINES...................................................................................... 10 Components of Systematic Conservation Planning................................................................................. 10 Compilation and Assessment of Data...................................................................................................... 11 Identifying Goals and Targets.................................................................................................................. 11 Conservation Elements ....................................................................................................................... 11 Evaluation Units ................................................................................................................................. 13 Setting Targets .................................................................................................................................... 14 Initialization Areas.............................................................................................................................. 15 Prioritization of Areas for Conservation.................................................................................................. 16 Other Conservation Planning Measures................................................................................................... 18 Irreplaceability .................................................................................................................................... 18 Environmental Space Analysis ........................................................................................................... 19 Cautions: Issues with Conservation Planning and this Approach............................................................ 20 CHAPTER 3: STUDY AREA........................................................................................ 21 Geology ................................................................................................................................................... 21 Soils ......................................................................................................................................................... 24 Topography.............................................................................................................................................. 24 Climate .................................................................................................................................................... 26 Hydrology................................................................................................................................................ 29 Edwards Aquifer ................................................................................................................................. 30 Ecology, Flora, and Fauna....................................................................................................................... 33 Area as a Transition Zone................................................................................................................... 33 Edwards Plateau.................................................................................................................................. 34 Blackland Prairie................................................................................................................................. 35 Post Oak Savannah and Lost Pines ..................................................................................................... 35 Species and Species Assemblages of Concern ........................................................................................ 36 Human Land Use..................................................................................................................................... 37 Early Humans ..................................................................................................................................... 37 Current and Future Human Populations.............................................................................................. 38 Open Space and Conservation ................................................................................................................. 39 Austin Tomorrow Plan........................................................................................................................ 41 Water Conservation Efforts ...............................................................................................................