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Weedy Pasture Plants for Salinity Control Sowing the seeds of destruction Weedy Pasture Plants for Salinity Control: Sowing the Seeds of Destruction Authors: Carol Booth, Geoff Carr, Tim Low G. Carr: Ecology Australia Pty Ltd; Hon. Research Assoc. National Herbarium of Victoria; Invasive Species Council. C. Booth, T. Low: Invasive Species Council. Date: November 2009 Design: John Sampson © Invasive Species Council, 2009 The Invasive Species Council is a national conservation group formed in 2002 to campaign for better laws and policies to protect Australia’s natural environment from invasive plants, animals and micro-organisms. Website: www.invasives.org.au. Email: [email protected]. The Wilderness Society is a national, community-based, environmental advocacy organisation whose purpose is to protect, promote and restore wilderness and natural processes across Australia for the survival and ongoing evolution of life on Earth. Website: www.wilderness.org.au. Email: [email protected]. Inquiries: Invasive Species Council, PO Box 166, Fairfield Vic 3078. [email protected]. Photo credits for chapter thumbnails: Chapter 1 – Chid Gilovitz, www.flickr.com/photos/Indole/; Chapter 2 – Geoff Carr; Chapter 3 – Steve Dewey, Utah State University, Bugwood.org; Chapter 4 – Steve Hurst @ USDA-NRCS PLANTS database; Appendices – Steve Hurst @ USDA-NRCS PLANTS database. With thanks for support from the Melbourne Community Foundation Victoria Inc Contents SUMMARY ................................................4-7 native vegetation communities ...............22 3.4 Weed risk assessment ...........................50 Fire and hydrology .................................23 Federal government............................... 50 1. INTRODUCTION ..................................... 8 Threatened species ...............................23 Victorian Government ............................51 1.1 A cautionary tale ......................................8 2.3 Responses to weed risk Future Farm Industries CRC .................. 52 1.2 Australia’s salinity problems ..................... 8 of Tall Wheat Grass ................................24 3.5 Are there alternatives? ........................... 55 Causes of salinity ..................................... 8 Limited acknowledgement 3.6 Conclusion ............................................ 57 Extent and costs of salinity ...................... 8 of weed risk ...........................................24 Effects on biodiversity ............................10 State government risk assessment ........25 4. DISCUSSION AND CONCLUSION .......58 Plant-based pastoral Other assessments and 4.1 Business as usual ..................................58 approaches to salinity ............................11 recommendations.................................. 27 4.2 Abrogating responsibility ........................58 The failure of plant-based 2.4 Conclusion ............................................ 29 4.3 Ignoring conflicts of interest ................... 60 approaches to salinity ............................12 4.4 Paying lip service to risk assessment .....60 1.3 Australia’s weed problems .....................14 3. MORE SALINITY WEED RISKS ............ 36 4.5 Relying on voluntary restraint .................61 1.4 Weeds versus salinity ............................ 14 3.1 Introduction ........................................... 36 4.6 Ignoring biodiversity ...............................61 1.5 Aims & approaches of this study ............ 17 The CRC’s perennial intentions ..............36 4.7 Recommendations ................................ 62 3.2 Weed risks of the CRC program ............37 2. TALL WHEAT GRASS ............................ 18 Inherent weed risks of 5. REFERENCES ....................................... 64 2.1 Introduction ........................................... 18 exotic pasture plants ............................. 37 Tall Wheat Grass (Lophopyrum Promotion of existing invasive APPENDICES ............................................ 70 ponticum) .............................................. 18 species for saltlands ..............................39 Appendix 1: Institutions involved in planted- Agricultural use of Tall Wheat Development of new cultivars based responses to dryland salin- Grass for saltlands .................................19 of existing invasive species ....................41 ity ............................................ 70 2.2 Spread and impacts of Development of new potentially Appendix 2: Relevant Victorian Tall Wheat Grass .................................... 20 invasive pasture species ........................45 legislation and policy ................74 Extent of spread ....................................20 Weed risks of abandoned trial sites ....... 47 Appendix 3: Tables 3.2-3.4 ..........................75 Potential for spread ............................... 20 3.3 Other environmental risks ...................... 48 Appendix 4: Acknowledgements ................. 86 Impacts of Tall Wheat Grass .................. 22 Loss/degradation of remnant vegetation 48 Appendix 5: Glossary and Abbreviations ......87 Saltmarshes, wetlands & other Hydrological impacts .............................49 Summary In Victoria one environmental problem – salinity that have led to the promotion of serious failing to solve salinity problems. They have – is being used to justify the exacerbation of weeds. Our focus is Victoria, but many of little effect in many areas (such as wetter another much worse environmental problem the problems are common to other southern catchments), graziers are not planting them – weed invasion. Victorian farmers have been states as well. on the scale required to reduce salinity, and encouraged and subsidised to plant Tall in many catchments the extent of planting Wheat Grass (Lophopyrum ponticum) as a Salinity and perennial pastures required to address salinity (up to 50%) is salt-tolerant pasture. It has already escaped Dryland salinity is a well-recognised unrealistic. cultivation at hundreds of sites, and according environmental and agricultural problem, The extent of salinity and its costs to Victoria to a Victorian Government assessment, it attributed to the extensive replacement of could invade more than 10 million hectares are far outweighed by the threat and costs of native vegetation with crops and pastures of Victoria. Despite the government’s risk weeds. The area threatened by just one of the that have shallower roots and shorter growing assessment recommending that the invasion of weedy pasture plants promoted for salinity cycles, and use less of the soil water. In Tall Wheat Grass into saltmarshes be declared mitigation, Tall Wheat Grass, is more than Victoria 1-2% of agricultural land is reported to a threatening process, the government an order of magnitude greater than the area be affected by salinity. has continued to promote its planting. The threatened by salinity. Yet the weed risks are department that developed and released the Governments, Catchment Management mostly ignored or downplayed. most commonly planted cultivar of Tall Wheat Authorities and agronomists have strongly Grass is the same department that manages promoted the cultivation of perennial pasture Tall Wheat Grass weed declarations. species as a solution for salinity problems. Lophopyrum ponticum is a productive exotic Perennial plants use more water than annual Other weedy pasture plants are also being grass palatable to sheep and cattle. The species, limiting the leakage of water into promoted for saline areas or to help control Victorian Department of Primary Industries, groundwater and reducing mobilisation of salts salinity across southern Australia, and which developed and released in 1999 the in the soil. Some perennial pasture species agronomists are developing new pasture Dundas cultivar, considers that it has “the such as Tall Wheat Grass are salt-tolerant, so varieties for this purpose that are likely to be potential to reclaim most of the salt affected can be cultivated on salinised sites. invasive. Although the Future Farm Industries unproductive areas on farms within Victoria Cooperative Research Centre now conducts However, Victoria’s dryland salinity problems and other states”. weed risk assessments on proposed new have proved to be more localised and smaller Tall Wheat Grass is invasive in many countries, releases, standards are so low that ‘high risk’ in extent than previously estimated. Drier including in Australia’s southern states. It has plants can be released. conditions since the mid 1990s have stabilised extraordinary ecological amplitude, invading and reduced the salinity threat, and the drier In this report we examine the weed risks saltmarsh, wetlands, grasslands, estuaries, climate predicted under climate change will associated with salinity programs promoting coastal cliffs, waterways, roadsides and some further reduce the risk of salinity. exotic perennial pasture plants for salinity woodlands and tolerating drought, frost, mitigation, and identify the institutional failings Perennial pasture systems are in any event salinity, alkalinity and waterlogging. 4 – Weedy pasture plants for salinity control: Sowing the seeds of destruction Saltmarshes and wetlands are under particular Research Centre (CRC) is aiming for a tripling There are no requirements for graziers to threat. Tall Wheat Grass is a threat or potential of the area in Australia sown with perennial prevent the spread of non-declared weeds threat to several rare and threatened species, pastures

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