Production and quality of sap from the bigleaf maple (Acer macrophyllum Marsh) on Vancouver Island, British Columbia By Deirdre Bruce B.Sc. in Forestry, University of British Columbia, 2003 A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in the Department of Geography Deirdre Bruce, 2008 University of Victoria All rights reserved. This thesis may not be reproduced in whole or in part, by photocopy or other means, without the permission of the author. ii Production and quality of sap from the bigleaf maple (Acer macrophyllum Marsh) on Vancouver Island, British Columbia By Deirdre Bruce B.Sc. in Forestry, University of British Columbia, 2003 Supervisory Com m ittee Dr. Dan Smith, Co-Supervisor (Department of Geography) Dr. W illiam W agner, Co-Supervisor (Department of Geography) Dr. Dave Duffus , Supervisory Committee Member (Department of Geography) Dr. Simon Shamoun, External Examiner (Pacific Forestry Centre) ii iii Supervisory Committee Dr. Dan Smith, Co-Supervisor (Department of Geography) Dr. W illiam W agner, Co-Supervisor (Department of Geography) Dr. Dave Duffus , Supervisory Committee Member (Department of Geography) Dr. Simon Shamoun, External Examiner (Pacific Forestry Centre) Abstract Bigleaf maple tapping has become increasingly popular on Vancouver Island and additional information is needed to assist in the sustainable development of this non- timber forest product. This research is an exploratory study that investigates sap flow in the 2006/2007 season on Vancouver Island, British Columbia. Sap flow was highly variable throughout the season. Fluctuations in air temperature, above and below zero, were shown to trigger sap flow. This study characterizes the dissolved solid components of the sap and syrup collected during the 2006/2007 season. The carbohydrate content of the bigleaf maple sap is mainly sucrose with a minor component of fructose and glucose. The concentration of carbohydrates varied throughout the season. The main cations in the bigleaf maple sap and syrup are calcium, potassium and magnesium. iii iv Table of Contents Supervisory Committee ................................................................................................ ii Abstract........................................................................................................................iii Table of Contents......................................................................................................... iv List of Figures.............................................................................................................. vi List of Tables .............................................................................................................. vii Acknowledgments......................................................................................................viii Dedication..................................................................................................................... x Chapter One: Introduction ............................................................................................ 1 1.1 Introduction......................................................................................................... 1 1.2 Forestry in British Columbia .............................................................................. 1 1.3 The Potential of Non-timber Forest Products ..................................................... 4 1.4 British Columbia Forest Policy........................................................................... 7 1.5 Objectives of The Study...................................................................................... 9 1.6 References......................................................................................................... 10 Chapter Two: Research Background .......................................................................... 13 2.1 Description of the Bigleaf Maple...................................................................... 13 2.2 Geographic Distribution.................................................................................... 15 2.3 Habitat............................................................................................................... 19 2.4 Bigleaf Maple Regeneration ............................................................................. 20 2.5 Ecological Importance of the Bigleaf Maple.................................................... 21 2.6 Cultural Importance of the Bigleaf Maple to Coastal First Nations ................. 24 2.7 Bigleaf Maple Management.............................................................................. 24 2.71 Bigleaf Maple Control ................................................................................ 28 2.8 Timber Uses...................................................................................................... 31 2.9 Non-timber Uses ............................................................................................... 32 2.10 Maple Physiology ........................................................................................... 33 2.11 Maple Carbohydrates and Cations.................................................................. 34 2.12 References....................................................................................................... 37 Chapter Three: Yield and Characteristics of Bigleaf Maple Sap............................... 41 3.1 Introduction to Sap Flow Characteristics.......................................................... 41 3.2 Methods............................................................................................................. 43 3.2.1 Study Sites and Plot Selection ................................................................... 44 3.2.2 Sap Flow Measurement.............................................................................. 47 3.2.3 Climate Data .............................................................................................. 49 3.2.4 Soil Analysis .............................................................................................. 49 3.2.5 Data Analysis............................................................................................. 51 3.3 Results and Discussion ..................................................................................... 52 3.3.1 Sap Flow and Air Temperature.................................................................. 52 3.3.2 Seasonal and Monthly Flows..................................................................... 56 3.3.3 Soil Type and Flow.................................................................................... 60 3.3.4 Diameter at Breast Height (DBH) and Flow.............................................. 63 3.3.5 Edge Versus Non-Edge and Flow.............................................................. 65 3.5.6 Sap Flow Model......................................................................................... 66 iv v 3.4 Limitations ........................................................................................................ 67 3.5 Conclusions....................................................................................................... 68 3.6 References......................................................................................................... 70 Chapter Four: Chemical Analysis of Bigleaf Maple Sap and Syrup .......................... 72 4.1 Introduction....................................................................................................... 72 4.2 Methods............................................................................................................. 73 4.3 Results and Discussion ..................................................................................... 76 4.3.1 Bigleaf Maple Sap Carbohydrates and Cations ......................................... 76 4.3.2 Bigleaf Maple Syrup Carbohydrates and Cations...................................... 80 4.4 Limitations ........................................................................................................ 84 4.5 Conclusions....................................................................................................... 84 4.6 References......................................................................................................... 86 Chapter Five: Summary .............................................................................................. 88 5.1 Summary of Research....................................................................................... 88 5.2 Social Benefits of Syrup Production................................................................. 89 5.3 Tapping into the Economic Benefits................................................................. 92 5.4 Future Research and Forest Management Recommendations.......................... 96 5.5 References......................................................................................................... 99 Appendix 1................................................................................................................ 101 Vita............................................................................................................................ 102 v vi List of Figures Figure 1. Bigleaf maple flowers.................................................................................. 15 Figure 2. The native range of bigleaf maple trees (modified from Minore & Zasada 1990). .........................................................................................................................