Oral Presentation Australian Society for Limnology Congress 2013

Is prolonged waterlogging killing Victoria's faunal emblems? (#44)

Joe Greet 1 2
  1. The University of Melbourne, Parkville, Australia
  2. Melbourne Water, Melbourne

Eucalyptus camphora swamp forest within the Yellingbo Nature Conservation Reserve provides habitat for both of Victoria’s faunal emblems: the critically endangered Helmeted Honeyeater and the endangered Leadbeater’s Possum. Habitat values of the reserve are currently under threat from the dieback of E. camphora swamp forest and a lack of natural regeneration. Altered water regime resulting from drainage works carried out in the 1950s for agricultural purposes is considered a causal factor in both these threatening processes. The drainage works led to channel incision, erosion and sediment deposition downstream within the swamp impeding drainage and resulting in prolonged waterlogging. I will present research into the water regime requirements of E. camphora. This research includes monitoring of reproductive phenology and nursery-based flooding experiments to determine the water regime requirements of E. camphora at two different life-history stages: seed release and seedling establishment and growth. Results from seed release monitoring suggest that the reproductive phenology of E. camphora is adapted to natural hydrologic regimes. Results from flooding experiments suggest that its seedling establishment is also dependent on appropriate water regimes with increasing depth and duration of flooding reducing seedling survival and growth and overtopped seedlings sensecing rapidly. The implications of the research will be used to inform capital works to be implemented at the site aimed at naturalising water regimes in order to arrest dieback and promote regeneration of E. camphora swamp forest at Yellingbo.