Genetic Pollution from Farm Forestry Using Eucalypt Species and Hybrids
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Genetic Pollution from Farm Forestry using eucalypt species and hybrids A report for the RIRDC/L&WA/FWPRDC Joint Venture Agroforestry Program by Brad M. Potts, Robert C. Barbour, Andrew B. Hingston September 2001 RIRDC Publication No 01/114 RIRDC Project No CPF – 3A © 2001 Rural Industries Research and Development Corporation. All rights reserved. ISBN 0 642 58336 6 ISSN 1440-6845 The risk of genetic pollution from farm forestry using eucalypt species and hybrids Publication No. 01/114 Project No. CPF – 3A The views expressed and the conclusions reached in this publication are those of the authors and not necessarily those of persons consulted. RIRDC shall not be responsible in any way whatsoever to any person who relies in whole or in part on the contents of this report. This publication is copyright. However, RIRDC encourages wide dissemination of its research, providing the Corporation is clearly acknowledged. For any other enquiries concerning reproduction, contact the Publications Manager on phone 02 6272 3186. Researcher Contact Details (Dr. Brad M. Potts and Robert C. Barbour) (Andrew Hingston,) (CRC for Sustainable Production Forestry, CRC for Sustainable Production Forestry, School of Plant Science, School of Geography and Environmental Studies, University of Tasmania, University of Tasmania, G.P.O. Box 252-55, G.P.O. Box 252-78, Hobart 7001, Tasmania, Australia ) Hobart 7001, Tasmania, Australia ) Phone: 03 62262641 Phone: 03 62262641 Fax: 03 62262698 Fax: 03 62262698 Email: [email protected] Email: [email protected] [email protected] RIRDC Contact Details Rural Industries Research and Development Corporation Level 1, AMA House 42 Macquarie Street BARTON ACT 2600 PO Box 4776 KINGSTON ACT 2604 Phone: 02 6272 4539 Fax: 02 6272 5877 Email: [email protected] Website: http://www.rirdc.gov.au Published in September 2001 Printed on environmentally friendly paper by Canprint ii Foreword The rapid expansion of eucalypt plantations and restoration plantings in Australia has increased concerns of the risk of genetic pollution of native eucalypt gene pools. This publication reviews the risks of genetic pollution and potential impacts on local biodiversity from planting non-native eucalypt species and hybrids in Australia. It develops a framework for risk assessment and identifies key research required for the development of management strategies. This project was funded by the Joint Venture Agroforestry Program (JVAP). The JVAP is supported by three R&D Corporations — Rural Industries, Land & Water Australia and Forest and Wood Products. These Corporations are funded principally by the Federal Government. This report, a new addition to RIRDC’s diverse range of over 700 research publications, forms part of our Agroforestry and Farm Forestry R&D program, which aims to integrate sustainable and productive agroforestry within Australian farming systems. Most of our publications are available for viewing, downloading or purchasing online through our website: • downloads at www.rirdc.gov.au/reports/Index.htm • purchases at www.rirdc.gov.au/eshop Peter Core Managing Director Rural Industries Research and Development Corporation iii Acknowledgements The authors wish to thank Heidi Dungey, Peter Gore, David Lee, Jim Reid, Robert Wiltshire and René Vaillancourt for their comments on the report, and Meredith Wallwork and Kate Delaporte for providing unpublished information on new hybrid combinations. We also thank Sharon Davis of RIRDC/JVAP for her support and advice. iv Contents Foreword………………………………………..…………………………...………………………...iii Acknowledgements……………………………………………………….………………………...…iv Executive Summary……………………………………………………………………………….…viii 1. INTRODUCTION......................................................................................................................................... 1 1.1 PLANT INVASIONS .................................................................................................................................... 1 1.2 GENETIC POLLUTION................................................................................................................................1 1.2.1 Definition ........................................................................................................................................ 1 1.2.2 The process of invasion................................................................................................................... 3 1.2.3 Importance of hybridisation in plants............................................................................................. 3 1.2.4 Common examples of genetic pollution .......................................................................................... 3 1.3 AUSTRALIAN EUCALYPT FORESTS AND PLANTATIONS.............................................................................. 6 2. NATURAL HYBRIDISATION IN EUCALYPTS .................................................................................... 9 2.1 INTRODUCTION ........................................................................................................................................ 9 2.2 PATTERNS AND LEVELS OF NATURAL HYBRIDISATION.............................................................................. 9 2.3 INTROGRESSION AND GENETIC INVASION ............................................................................................... 12 3. POTENTIAL SOURCES OF GENETIC POLLUTION OF EUCALYPT FOREST .......................... 15 3.1 EXOTIC SPECIES ..................................................................................................................................... 15 3.1.1 How genetically different are species? ......................................................................................... 16 3.2 ARTIFICIAL HYBRIDS.............................................................................................................................. 17 3.2.1 General.......................................................................................................................................... 17 3.2.2 Are hybrids any more risky than exotic species? .......................................................................... 18 3.3 EXOTIC PROVENANCES........................................................................................................................... 21 3.3.1 General.......................................................................................................................................... 21 3.3.2 How different are provenances of Eucalyptus? ............................................................................ 22 3.3.3 Fitness of local gene pools............................................................................................................ 24 3.4 ARTIFICIALLY SELECTED PLANTS........................................................................................................... 29 3.5 GENETICALLY MODIFIED (TRANSGENIC) PLANTS ................................................................................... 29 3.5.1 General.......................................................................................................................................... 29 3.5.2 Genetically modified forest trees................................................................................................... 30 3.5.3 Genetically modified eucalypts ..................................................................................................... 34 3.5.4 Impacts of genetically modified eucalypts on biodiversity............................................................ 35 4. POTENTIAL IMPACTS ON LOCAL BIODIVERSITY ....................................................................... 36 4.1 SCENARIO 1: REPLACEMENT OF NATIVE VEGETATION ............................................................................ 36 4.1.1 Previous studies of biodiversity in plantations ............................................................................. 36 4.1.2 Loss of forest structural diversity.................................................................................................. 36 4.1.3 Loss of plant species diversity....................................................................................................... 37 4.1.4 Fragmentation of native forest...................................................................................................... 38 4.2 SCENARIO 2: REPLACEMENT OF FARMLAND ........................................................................................... 39 4.3 SCENARIO 3: ESTABLISHMENT ADJACENT TO NATIVE VEGETATION........................................................ 39 4.3.1 Direct effects on biodiversity in adjacent vegetation .................................................................... 39 4.3.2 The impact of hybridisation on biodiversity.................................................................................. 39 4.3.3 Impact of plantation eucalypts on pollination in native vegetation .............................................. 40 5. A FRAMEWORK FOR RISK MANAGEMENT.................................................................................... 40 5.1 IDENTIFICATION OF CONSERVATION VALUES ......................................................................................... 42 5.2 POLLEN QUANTITY: ‘SOURCE VS SINK’ .................................................................................................. 43 5.2.1 Population size.............................................................................................................................