Recovery of Rare and Threatened Flora After the 2002 Wildfire and Vital Attributes to Assist Ecological Fire Management in the Big Desert, Western Victoria
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Arthur Rylah Institute Technical Report Series No. 150 Recovery of Rare and Threatened Flora after the 2002 Wildfire and Vital Attributes to Assist Ecological Fire Management in the Big Desert, Western Victoria Arthur Rylah Institute for Environmental Research Recovery of Rare and Threatened Flora after the 2002 Wildfire, and Vital Attributes to Assist Ecological Fire Management in the Big Desert, Western Victoria Oberon Carter and David Cheal Final Report – August 2004 Cover Photo: Helichrysum adenophorum var. adenophorum in recently burnt Heathy Mallee, Big Desert II Published by the Victorian Government Department of Sustainability and Environment Melbourne, July 2004 © The State of Victoria Department of Sustainability and Environment 2004 This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act 1968. Authorised by the Victorian Government, 8 Nicholson Street, East Melbourne. ISBN 1 74106 947 5 ISSN 0810 5774 Arthur Rylah Institute Technical Report Series: No. 150 For more information contact the DSE Customer Service Centre 136 186 Disclaimer This publication may be of assistance to you but the State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication. Citation Carter, O. & Cheal, D. (2004) Recovery of Rare and Threatened Flora after the 2002 Wildfire, and Vital Attributes to Assist Ecological Fire Management in the Big Desert, western Victoria. Arthur Rylah Institute for Environmental Research Technical Report Series No. 150. Department of Sustainability and Environment, Heidelberg Victoria III Contents Executive Summary ………………………………………………………………………………………………...…………………… V Introduction ……………………………………………………………….………………………….…………………..………………… 6 Objectives ……………………………………………………………...…………………………………………….…..………………… 7 Methodology ………………………………………………………………………………………………………………………………... 8 Threatened Species ………………………………………………….…………….………………………………………………… 9-29 Acacia oswaldii ………………………………………………………………………………………….……………………… 9 Austrostipa hemipogon/mollis ……………………………………………………………………………………… 10-11 Comesperma scoparium ………………………………………………….………….………………….…………… 12-14 Haloragis acutangula forma acutangula .………………………………………………………………….………… 15 Helichrysum adenophorum var. adenophorum ………………………………………………………….…… 16-17 Lawrencia berthae ………………………………………………………………………………..…….……………… 18-19 Leucopogon costatus ……………………………..………………………………..……………………………………… 20 Microcybe multiflora subsp. multiflora ……………………………………………...………………..………… 21-23 Phyllota remota ………………………………………………..………………………………………………………… 24-26 Schoenus racemosus ……………………………………………………………....…………………...………………… 27 Stenopetalum velutinum ………………………………………………………………………..……….…………… 28-29 Teucrium sessiliflorum ……………………………………………………………………………………………………… 30 Threatened Ecological Vegetation Classes …………………………………………….……………………………..…… 32-34 Vital Attributes to assist ecological fire management ………………………………………………….……………… 35-37 Recommendations ………………………………………………………………………………………………………………….. 38-42 Bibliography ……………………………………………………………………………….………………………….……………… 43-44 Appendixes: 1. Rare or threatened plants recorded from within the perimeter of the 2002 Big Desert wildfire ……………………………………………………….…………………………………………..……………….…………… 45-46 2. Vital Attributes of plants from Heathy Mallee and Sandplain Heath in the Big Desert and Wyperfeld National Park, collected in April and June 2004 ………………………………………….….. 48-59 List of Tables Table 1. Rare or threatened plants targeted or recorded in, or near, to the Big Desert 2002 Wildfire area during survey in 2004 …………………….…..……………. 8 Table 2. Plants recorded in Eucalyptus porosa-dominated vegetation at Gunners Reserve on 5th April 2004 ………………………………………………………………. 33 Table 3. The vital attributes scheme …………………………….………………………………………….………………….. 34 IV Executive Summary The status and post-fire recovery of eleven rare and threatened plant species in or near the Big Desert were assessed. Five threatened taxa were observed recruiting successfully within the perimeter of the 2002 Big Desert fire area. They were Comesperma scoparium, Helichrysum adenophorum var. adenophorum, Leucopogon costatus, Phyllota remota and Stenopetalum velutinum. However, only two of these were recruiting in high numbers in areas searched, ie. Comesperma scoparium and Phyllota remota. Both H. adenophorum var. adenophorum and S. velutinum had not been previously recorded for many years and there are no quadrat records of either of these taxa in DSE's Flora Information System. The regionally threatened taxa Haloragis acutangula forma acutangula, Lawrencia berthae and Microcybe multiflora were also assessed from nearby roadsides Vital attribute data were collected for 141 plant taxa in the Big Desert and Wyperfeld National Park to augment DSE’s existing vital attributes database. A range of fire ages was assessed to gain insight into the timing of reproductive stages (life-history transitions) in a range of common and threatened plant taxa. These data can be used to support future planning of applied ecological burning in mallee and heathland vegetation in north-western Victoria and elsewhere in the state where these species (or their ecological analogs) occur. V Introduction There are approximately 36 Victorian rare or threatened plant species recorded from areas affected by the recent wildfires in north-western Victoria (Big Desert). Some of these species are likely to have priority for risk management in the post fire environment (See Appendix 1 for a full list of threatened taxa recorded from areas likely to have been affected by the 2002 wildfire). Map 1. Extent of the December 2002 Wildfire in the Big Desert. Fire boundary courtesy of DSE Mildura. Other data sourced from DSE Corporate Library. 2002 Scale is 1 cm ≅ 20 km. The status of affected Ecological Vegetation Classes (EVCs) is less certain, as public land mapping utilising the recent EVC typology and classification, has not yet been incorporated into DSE datasets. It is likely that a poorly-defined, and threatened, EVC (dominated by Black Mallee Box, Eucalyptus porosa) occurs in the burnt area. Of particular concern, and likely to require an immediate management response are threats associated with pest plants and animals, and with the impacts of fire suppression works, particularly mineral earth and slashed fire breaks. These have been rated as posing high to medium-high risk, but have not been specifically assessed for impacts on populations of threatened flora and vegetation in the field. The Statewide Fire Recovery Plan has identified that management is required to address the impact of fire suppression activities and the impacts of fire on the natural environment and water quality. Its objectives include: • Minimise potential invasion by pest plants and animals exacerbated by fire, caused by soil disturbance and/or the opening of access into previously inaccessible areas. • Identify any ongoing threats to flora and fauna values, particularly rare or threatened species, which may be a consequence of the suppression activities or threatening processes exacerbated by the fire. • Identify species, communities, sites or areas requiring special protection from disturbance to enable recovery. Key outcomes for natural values protection identified in the Statewide Fire Recovery Plan include: • Monitoring the status and recruitment of a range of rare and threatened plant species and EVCs. 6 • Identifying and implementing priority actions to mitigate any identified threats. This project will determine the impact of risks on rare or threatened species and EVCs, identify urgent management actions and monitor progress toward recovery. Specific attention will be paid to potential for weed invasion. Risks associated with bulldozer works for suppression or rehabilitation (“High Risk”) will be investigated, particularly in relation to post-fire recovery of flora and weed invasion. Targeted searches for rare or threatened species known from the fire area and the general vicinity will also be conducted. An opportunity also exists to compile vital attributes information for inclusion in the Statewide and national fire response databases which underpin ecological fire management protocols currently being developed by the Department of Sustainability and Environment and Parks Victoria. Objectives • Determine the current status of rare or threatened flora and EVCs. • Identify threats to post fire recovery of rare or threatened flora and EVCs. • Identify management requirements for rare or threatened flora and EVCs. • Provide a baseline against which post fire recovery of rare or threatened flora and EVCs can be evaluated. 7 Methodology Five taxa were selected for targeted searches of previously recorded locations, which are within, or near to, the Big Desert 2002 wildfire area. Taxa were selected on the basis of their perreniality and hence likelihood of re-location in the post-fire environment, and known life- history characteristics. Populations of seven rare or threatened taxa were also found opportunistically in the process of either gathering vital attribute information or searching for targeted species in recently-burnt areas. Table 1 provides a list of rare or threatened species recorded during this project. Table 1. Rare or threatened plants targeted or recorded in, or near, to