Determining the Effectiveness of Vegetation Management Programs Measures and Methodologies - Literature Review
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Determining the Effectiveness of Vegetation Management Programs Measures and Methodologies - Literature Review RIRDC/LWRRDC/FWPRDC Joint Venture Agroforestry Program (supported by the Natural Heritage Trust and the Murray Darling Basin Commission) and Environment Australia RIRDC Publication No 99/130 RIRDC Project No MS967-43 © 2000 Rural Industries Research and Development Corporation. All rights reserved. ISBN 0 642 57936 9 ISSN 1440-6845 Determining the Effectiveness of Vegetation Management Programs – Measures and Methodologies Publication no 99/130 Project no. MS967-43 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 Centre for International Economics CSIRO GPO Box 2203 Division of Wildlife and Ecology Canberra ACT 2601 Gungahlin Homestead Barton highway Phone: 02 6248 6699 CRACE ACT 2911 Fax: 02 6247 7484 GPO Box 284 Email: [email protected] CANBERRA CITY ACT 2601 Phone: 02 6242 1600 Website: http://www.csiro.au/index.asp 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 Environment Australia Contact Details Department of the Environment and Heritage John Gorton Building Parkes Place Parks ACT 2600 GPO Box 787 CANBERRA ACT 2601 Phone: 02 6274 1111 Fax: 02 6274 1123 Website: http://www.environment.gov.au Published in January 2000 Printed on environmentally friendly paper by Union Offset ii Foreword Vegetation management has been used as a tool in many land, water, conservation and agricultural improvement projects. This literature review was initiated to survey current knowledge of the biological, physical and socio-economic processes occurring in these projects so that useful indicators linking actions to final outcomes could be identified more easily. This wide ranging review includes research on salinity, soil conservation, water quality, biodiversity, wood production, crop yields, infrastructure damage and carbon sequestration. It also encompasses the success or otherwise of programs directed at changing people's behaviour in relation to conservation programs and suggests areas in need of further research. The report was initiated as part of a consultancy concerned with Measures and methodologies to determine the effectiveness of vegetation management programs. The consultant team consisted of the Centre for International Economics (CIE) and the CSIRO, and was funded by Environment Australia (EA), through Bushcare, a Natural Heritage Trust program, and the RIRDC/LWRRDC/FWPRDC Joint Venture Agroforestry Program. RIRDC's involvement in this project and in the Joint Venture Agroforestry Program, is part of the Corporation's Agroforestry and Farm Forestry R&D Program which aims to foster integration of sustainable and productive agroforestry within Australian farming systems. Most of our diverse range of over 400 research 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/pub/cat/contents.html Peter Core Managing Director Rural Industries Research and Development Corporation iii Contents Foreword iii Contents iv Executive Summary viii 1 Introduction 1 1.1 PURPOSE 1 1.1.1 THE FRAMEWORK 1 2 Biophysical processes — conservation outcomes 5 2.1 INTRODUCTION 5 2.1.1 KEY ISSUES 5 2.1.2 METHODOLOGY 5 2.2 SALINITY 7 2.2.1 OVERVIEW OF THE PROBLEM 7 2.2.2 REDUCING GROUNDWATER RECHARGE 8 2.2.3 INCREASING GROUNDWATER DISCHARGE 9 2.2.4 FACTORS CONTROLLING THE RATE OF WATER USE 10 2.2.5 EVALUATING THE EFFECTIVENESS OF VEGETATION 11 2.3 SOIL CONSERVATION 15 2.3.1 OVERVIEW OF THE PROBLEM 15 2.3.2 SURFACE COVER PROTECTION FROM WIND AND WATER 17 2.3.3 AERIAL COVER PROTECTION FROM WATER 19 2.3.4 AMELIORATION AND ENHANCEMENT OF SOIL PROPERTIES 20 2.3.5 PREDICTIVE MODELLING 22 2.4 WATER QUALITY 22 iv 2.4.1 OVERVIEW OF THE PROBLEM 22 2.4.2 RIPARIAN BUFFERS TO AMELIORATE STREAM FUNCTION 24 2.4.3 RIPARIAN VEGETATION TO STABILISE STREAM BANKS 26 2.5 BIODIVERSITY 27 2.5.1 OVERVIEW OF THE PROBLEM 27 2.5.2 BUFFER STRIPS 29 2.5.3 CORRIDORS 30 2.5.4 INCREASED HABITAT 33 2.5.5 LANDSCAPE STABILISATION 34 2.6 IMPLICATIONS FOR INDICATOR DEVELOPMENT 34 2.6.1 SALINITY CONTROL 34 2.6.2 SOIL CONSERVATION 36 2.6.3 IMPROVING WATER QUALITY 36 2.6.4 CONSERVATION OF BIODIVERSITY 37 3 Biophysical processes — sustainable production 39 3.1 DEFINING SUSTAINABILITY 39 3.2 BENEFITS FROM CONSERVATION OUTCOMES 42 3.2.1 DRYLAND SALINITY 42 3.2.2 SOIL DEGRADATION 43 3.2.3 SURFACE WATER (ON-SITE) 45 3.3 BENEFITS FROM VEGETATION INPUTS 46 3.3.1 SHADE AND SHELTER 46 3.3.2 PEST CONTROL 49 3.4 NEW PRODUCTS FOR SUSTAINABLE PRODUCTION 51 3.4.1 WOOD 51 3.4.2 OTHER PRODUCTS 53 v 3.5 OFF-SITE PRODUCTION EFFECTS 54 3.5.1 CARBON SEQUESTRATION 54 3.5.2 INFRASTRUCTURE 56 3.6 IMPLICATIONS FOR INDICATORS 57 3.6.1 CONSERVATION OUTCOMES AND PRODUCTION 57 3.6.2 SHADE AND SHELTER AND PRODUCTION 57 3.6.3 PEST CONTROL AND PRODUCTION 58 3.6.4 NEW PRODUCTS 58 3.6.5 CARBON SEQUESTRATION 60 3.6.6 OTHER USES 60 4 Investigating the socioeconomic impacts 61 4.1 PEOPLE AND INSTITUTIONAL OUTCOMES — DO THEY LEAD TO CHANGE? 62 4.1.1 IS PECUNIARY RETURN THE MAIN INCENTIVE FOR ADOPTION? 64 4.1.2 SURVEY EVIDENCE ON CHANGES IN BEHAVIOUR 64 4.1.3 MEASURING MULTIPLIER EFFECTS 66 4.1.4 IMPLICATIONS FOR INDICATORS 69 4.2 FINAL OUTCOMES: HOW ARE THEY VALUED? 69 4.2.1 BROAD BASED ESTIMATES 70 4.2.2 ON-SITE USE VALUES 72 4.2.3 OFF-SITE USE VALUES: CARBON SEQUESTRATION 76 4.2.4 OFF-SITE USE VALUES: INFRASTRUCTURE MAINTENANCE COSTS 78 4.2.5 OTHER OFF-SITE USE VALUES 79 4.2.6 NON-USE VALUES 81 4.2.7 IMPLICATIONS FOR VALUING THE OUTCOMES OF THE PROGRAMS 83 5 Towards indicators – existing indicator programs 85 5.1 SOE REPORTING 85 5.1.1 SCALE OF DATA COLLECTION 85 vi 5.1.2 REPORTING LEVEL 85 5.2 NATIONAL LAND AND WATER RESOURCES AUDIT 86 5.2.1 SCALE OF DATA COLLECTION 86 5.2.2 REPORTING LEVEL 87 5.3 MONTREAL PROCESS 87 5.3.1 SCALE OF DATA COLLECTION 87 5.3.2 REPORTING LEVEL 88 5.4 INDICATORS DEVELOPED BY THE STANDING COMMITTEE ON AGRICULTURE AND RESOURCE MANAGEMENT 88 5.4.1 SCALE OF DATA COLLECTION 89 5.4.2 REPORTING LEVEL 90 5.5 OTHER INDICATOR PROGRAMS 90 5.6 SUMMARY 90 6 Conclusions 91 References 92 vii Executive Summary Many research and management projects involving vegetation management have been carried out in Australia. The RIRDC/LWWRDC/FWPRDC Joint Venture Agroforestry Program has been supporting R&D into agroforestry and farm forestry since 1993. The guiding objective of the program is to integrate sustainable and productive agroforestry within Australian farming systems. More recently, activity in the area of integrating vegetation into Australian farming systems has increased under the Natural Heritage Trust (NHT) initiative, particularly through the Bushcare and Farm Forestry Programs. This literature review aims to describe the results of research work on vegetation and its impacts on the biological and physical environment, as well as production and socio-economic outcomes. In keeping with the key outcome areas of the Natural Heritage Trust, the impacts of these projects are reported here against four areas: environment, sustainable production, people, integration and institutions. In each area, a framework linking the processes to outcomes, with relevant indicators for monitoring is presented. Biophysical processes-conservation outcomes Firstly, the review investigates biophysical processes for attaining conservation outcomes, to examine evidence as to whether on ground actions, such as establishing vegetation and/or protecting remnant vegetation, produce desired outcomes, such as reducing watertables and salinity, improving soil conservation and water quality, and protecting biodiversity. There is considerable uncertainty about the links between on-ground actions and conservation outcomes. Further investigation of the biophysical processes for dryland salinity control, in particular, is required. Tree planting in recharge locations can contribute to the control of dryland salinity. Trees use more water, from deeper in the soil profile, throughout the year compared to annual crops and pastures, reducing the amount of water reaching the watertable. Whether this effect is significant enough to halt, or reverse, the process of salinisation depends on the extent of the area that is planted to trees, and the location in which they are planted. Tree planting in discharge areas is not a solution to dryland salinity, but rather a ‘band-aid’ approach to the problem. Modelling may allow predictions about how long it will take for revegetation to exert control over rising watertables. However, it is probable that the rate of the response is dependent on the area that is planted, the location planted, the hydro-geology of the catchment and the species planted. Vegetation can be effective in reducing wind and water erosion of soils. Benefits are maximised through a combination of trees, shrubs and ground cover plants, as well as litter, to protect the soil surface from raindrop splash and to obstruct overland flow.