Managing and Rehabilitating Riparian Vegetation the Condition and Extent of Native Riparian and Vegetation Along Australia’S Rivers and Streams Varies Greatly
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RPLWRRDC’S RIPARIAN LANDSRP MANAGEMENT NEWSLETTER A COMPONENTia OF THE RIVER RESTORATION AND MANAGEMENT PROGRAM ANAGING Managing and rehabilitating riparian vegetation The condition and extent of native riparian and vegetation along Australia’s rivers and streams varies greatly. There are extensive areas Mrehabilitating dominated by native riparian vegetation, but there are also large tracts that have been riparian cleared, where the vegetation is fragmented, or where the vegetation has been largely replaced vegetation by introduced species. Where remnant native riparian vegetation occurs in agricultural regions, it is often confined to narrow strips, or is part of ‘bush run’ country used for grazing. Whilst much attention has been given to rehabilitating the badly degraded areas, remnant riparian vegetation has generally been left to look after itself. In many cases, it is gradually being degraded through overgrazing, high fire frequencies and weed invasion. continued page 3 EDITION 14, 1999 CONtents Theme: Managing and rehabilitating riparian vegetation 1 and 3 Case study 1: Natural regeneration of riparian vegetation in Western Australia 8 Case study 2: This publication is managed by Floodplain vegetation in Cooper Creek 11 the Land and Water Resources Getting a Grip: Notes from the field 13 Research and Development Local government focus 14 Corporation (LWRRDC), Case study 3: GPO Box 2182, Canberra Riparian vegetation in Tasmania 15 ACT 2601 Case study 4: Fire management on tropical savannas 18 LWRRDC’s mission is to provide New publication: Riparian Land Management Technical Guidelines 21 national leadership in utilising It’s a Wrap: News from around Australia R&D to improve the long-term 24 productive capacity, sustainable use, management and conservation of Australia’s land, water and vegetation resources. The Corporation will establish directed, integrated and focused programs where there is clear RIP rian lands: justification for additional public WHERE LAND AND WATER MEET funding to expand or enhance a the contribution of R&D to From the Editor sustainable management Welcome to another edition of RipRap. This edition is focusing on of natural resources. managing and rehabilitating the riparian zone, a topic that is highly relevant LWRRDC’s Home Page is: for those groups getting ready to submit projects for Natural Heritage www.lwrrdc.gov.au Trust funding. Practical information is provided on the steps that need to be followed in developing a riparian zone rehabilitation plan, with impor- Edition 14, October 1999 tant elements such as weed maintenance and implementing an ongoing RipRap is published four times a monitoring strategy highlighted. The advantages and disadvantages of year. Contributions and comments different revegetation strategies are provided in an easy to read format that are welcomed and should be groups can use to select the strategy most suited to their situation. addressed to the Editor. In addition, four case studies featuring new research findings on riparian zone vegetation are included, with issues such as fire management, Editor: Dr Siwan Lovett flooding, and the factors affecting recruitment and regeneration of native riparian species discussed. I hope you enjoy this edition and welcome any Feedback and comments to: Dr Siwan Lovett feedback and comments you might have on future themes for RipRap. LWRRDC Program Coordinator River Restoration and Riparian Lands LWRRDC, GPO Box 2182 Canberra ACT 2601 Tel: 02 6257 3379 Fax: 02 6257 3420 Email: [email protected] Website: www.rivers.gov.au Designed by: Angel Ink Printed by: Goanna Print ISSN 1324-6941 2 THEME CASE STUDY GETTING A GRIP IT’S A WRAP INFORMATION ANAGING and rehabilitating riparian vegetation M continued from page 1 3. Collect other environmental information relevant The highest priority for managing to the rehabilitation of riparian vegetation riparian vegetation should be to This information can be collected from reference sites considered to be in a protect areas in good condition natural condition, and might include data on climate, vegetation — channel morphology relationships, soil type and stream flow data, as well as infor- It is much more cost-effective to protect mation gained from reviewing aerial photos and orthophoto maps and any these areas now, than to rehabilitate them relevant literature. It is also useful to consult government agencies with later because of poor management. responsibilities in land management. For example, permits are usually Protecting areas in good condition provides benefits for water quality, required before any works on rivers can proceed. the physical condition of the stream, and aquatic and terrestrial ecology. 4. Ascertain the appropriate approach Management strategies should aim to In doing this, ask protect intact riparian vegetation and, in 1. are there any native species at the rehabilitation site? those situations where degradation has 2. are there intact stands of riparian vegetation nearby? occurred, seek to rehabilitate and restore. 3. is uncontrolled grazing a problem? 4. what problems other than vegetation-related ones need resolution? If the answer is ‘yes’ to the first three questions, the initial step will be to Developing a riparian remove or reduce the grazing pressure in order to protect the remnant zone rehabilitation plan native vegetation. This can be done in a number of ways, the most effec- When developing a plan for rehabilitating tive being fencing, with either a permanent fence or an electric one. It is riparian land, it is important to have a worth fencing and then waiting to see if there is any regeneration of native clear set of objectives. These objectives species from the soil-stored seed bank. If the answers to questions 1 and 2 may be to restore habitat values, reduce are ‘no’, but the answer to question 3 is ‘yes’, stock will need to be excluded erosion, manage weeds, improve water and the site will probably have to be planted with suitable native species. quality, increase farm productivity, or a For question 4, it is important to make sure the riparian zone (for example, combination of these things. It is impor- streambanks) is stable before committing the resouces to rehabilitation. tant that rehabilitation ultimately results in enhanced, rather than reduced, natural 5. Select species that suit the particular situation values. In developing a rehabilitation plan The priority should always be to replicate nature, but there will be many situa- the following steps should be taken. tions where this is not possible. Decisions will need to be made about what species are most suitable: using Australian natives not found in the area or 1. Assess the condition using introduced species will affect the outcome of the rehabilitation project. of the area to be rehabilitated This will involve documenting the vegetation’s 6. Work from the stream out condition (the extent and health of both native It is important to resolve any problems relating to stream channel stability vegetation and introduced species), the stream- before embarking on revegetating the streambanks. For example, if channel banks’ condition, and the impact of adjacent widening continues, much of the revegetation work might be wasted. land uses. 7. If the decision is made to revegetate, consider the 2. Conduct a local catchment survey most appropriate technique for the site and resources This survey will be less detailed than the survey of Try to gather as much information about the species — flowering periods, the rehabilitation site and will provide information time of seed set, germination requirements, typical habitat, and so on — relating to activities such as gravel extraction, that are present on or near the site to be rehabilitated and incorporate it forestry and stream regulation, that might affect in the revegetation strategy. In addition, soil cores can be collected and rehabilitation efforts. It will also provide informa- placed in trays to see what germinates. This will provide some indication tion about the best species to use in revegetation, of the capacity for natural regeneration, as well as information about as well as the ecological requirements and relation- which species are likely to germinate. Some form of treatment, such as ships between different species. heat or smoke, may be required for the regeneration of some species. It is THEME CASE STUDY GETTING A GRIP IT’S A WRAP INFORMATION 3 MANAGING and rehabilitating riparian vegetation important to get the timing of the different stages land, adjust both the stocking rates and the frequency of use to suit the of rehabilitation right. For example, don’t plant sensitive nature of the land. By following these simple rules, the riparian or direct seed if you need to take machinery onto zone can be used by managers to supplement feeding, provide shelter as the site for instream works at a later date. well as improve the quality of water upon which their animals depend. 8. Minimise disturbance 11. Other factors to consider: fire and feral animals during revegetation work Fire is an important component of the Australian landscape and is often Riparian land is sensitive to the use of heavy used as a tool in vegetation management. Because of the moist environ- equipment and other forms of physical interven- ment, fire is uncommon in many riparian lands, and there is little infor- tion, so it is important that careful planning mation available about riparian vegetation’s response to fire. Whilst many precede actual site preparation