Identifying Conservation Priority Estuaries in British Columbia with a Graph-Based Measure of Landscape Connectivity
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Identifying Conservation Priority Estuaries in British Columbia with a Graph-based Measure of Landscape Connectivity Lydia Rebecca Harrold B.E.S., University of Waterloo, 2003 RESEARCH PROJECT SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF RESOURCE MANAGEMENT In the School of Resource and Environmental Management Report No. 407 O Lydia Rebecca Harrold, 2006 SIMON FRASER UNIVERSITY Summer 2006 All rights reserved. This work may not be reproduced in whole or in part, by photocopy or other means, without permission of the author. APPROVAL Name: Lydia Rebecca Harrold Degree: Master of Resource Management Title of Research Project: Identifying Conservation Priority Estuaries in British Columbia with a Graph-based Measure of Landscape Connectivity Project No.: Supervisory Committee: Senior Supervisor: Dr. Kristina Rothley Assistant Professor in the School of Resource and Environmental Management Supervisor: Dr. Dan Esler Research Associate and Adjunct Professor with the Centre for Wildlife Ecology Date Defended: SIMON FRASER UN~VERS~TY~brary DECLARATION OF PARTIAL COPYRIGHT LICENCE The author, whose copyright is declared on the title page of this work, has granted to Simon Fraser University the right to lend this thesis, project or extended essay to users of the Simon Fraser University Library, and to make partial or single copies only for such users or in response to a request from the library of any other .university, or other educational institution, on its own behalf or for one of its users. The author has further granted permission to Simon Fraser University to keep or make a digital copy for use in its circulating collection, and, without changing the content, to translate the thesislproject or extended essays, if technically possible, to any medium or format for the purpose of preservation of the digital work. The author has further agreed that permission for multiple copying of this work for scholarly purposes may be granted by either the author or the Dean of Graduate Studies. It is understood that copying or publication of this work for financial gain shall not be allowed without the author's written permission. Permission for public performance, or limited permission for private scholarly use, of any multimedia materials forming part of this work, may have been granted by the author. This information may be found on the separately catalogued multimedia material and in the signed Partial Copyright Licence. The original Partial Copyright Licence attesting to these terms, and signed by this author, may be found in the original bound copy of this work, retained in the Simon Fraser University Archive. Simon Fraser University Library Burnaby, BC, Canada Summer ZOO6 ABSTRACT Predicting and ranking ecologically important estuaries supports estuary conservation efforts in British Columbia. Connectivity, an indicator of ecological importance, is not a component of rankings created to date by conservationists. I used graph theory to describe estuarine connectivity for three migratory birds: Dusky Canada Geese, Western Sandpipers, and White-winged Scoters and ranked estuaries based on their maintenance of connectivity. I developed seven metrics that quantified the importance of each estuary for connectivity at local and coastal scales. I computed the metrics and ranked estuaries separately for each species. Rankings were spatially proximal across species and indicated connectivity hot spots, i.e., collections of high- ranking estuaries within a restricted geographic area. Empirical observations of the focal species at connectivity hot spots verify that the graph model and connectivity metrics can predict important estuarine stopovers. These connectivity rankings are useful for prioritizing estuaries for conservation and for guiding future research. Keywords: Estuaries -- British Columbia, Landscape Connectivity, Landscape Ecology, Nature Conservation, Estuarine Reserves ACKNOWLEDGEMENTS I wish to express my gratitude to the following people for their contributions to my research project: Kris Rothley - This research project would not be the same without your expertise, insight, and dedication! Thank you for always being available to discuss connectivity, graph theory, and ArcView. Dan Esler -Thank you for ensuring the biological foundations of this research. I am grateful for your thought-provoking questions and editorial comments. Dan Buffett - You provided the estuary and elevation data that made this research possible! Thank you for your continued interest in my research and unceasing encouragement. Pat Wong -Thank you for providing the wind data. Ducks Unlimited Canada - Thank you for supporting my research financially. Greg Harrold - My rock. Thank you for your knowledge of programming and never-ending support. Christina Kereki - Thank you for chairing my defence and for being a part of so many of my REM experiences. REM Staff - Laurence, Bev, Iris, and Sarah, thank you for everything you have done to make my time at REM such a fulfilling experience. AWEL - Thank you fellow lab mates for being part of my REM experience and for supporting me through my research. TABLE OF CONTENTS .. Approval .......................................................................................................................................11 ... Abstract ........................................................................................................................................111 Acknowledgements ................................................................................................................... iv Table of Contents .........................................................................................................................v .. List of Tables ..............................................................................................................................vll ... List of Figures ............................................................................................................................vm Glossary ........................................................................................................................................ ix Estuary Conservation in British Columbia .............................................................................1 Objectives ......................................................................................................................................3 Background ....................................................................................................................................5 Shorebird and Waterfowl Migration in Coastal British Columbia..................................... 5 Landscape Connectivity and Reserve Design ....................................................................... 7 Measuring Landscape Connectivity ....................................................................................... 9 Methods of the Connectivity Analysis ...................................................................................13 Estuaries in British Columbia ............................................................................................... 13 Focal Species............................................................................................................................. 14 White-winged Scoters ......................................................................................................... 15 Western Sandpipers ........................................................................................................ 15 Dusky Canada Geese .......................................................................................................... 16 Measuring Functional Landscape Connectivity ................................................................ -17 Graph Theory as a Framework to Measure Connectivity ............................................. 18 Connectivity Metrics ............................................................................................................... 20 Local Connectivity Metrics ................................................................................................ 21 Coastal Connectivity Metrics ............................................................................................. 23 Data Description ...................................................................................................................... 24 Habitat Grid ......................................................................................................................... 24 Elevation Cost Grid ............................................................................................................. 26 Wind Cost Grid .................................................................................................................... 26 Ranking Estuaries for Connectivity Importance ................................................................. 28 Connectivity Importance per Species............................................................................... 29 Coastal vs . Local Connectivity .......................................................................................... 32 Connectivity Importance across Species .......................................................................... 33 Sensitivity Analysis ................................................................................................................. 34 Connectivity Importance in Relation to Biophysical Importance ...................................