The case for listing Mountain Ash forests in the Central Highlands of Victoria as a Threatened Ecological Community

Abstract

Context Thousands of species have been recognised as being at risk of extinction in formal listing processes such as those under the International Union for Conservation of Nature (IUCN). Less common is the recognition that some ecological communities are also at risk and for them to be formally listed. Under the Environment Protection and Biodiversity Conservation Act (EPBC Act) in Australia ~100 communities have been recognised as threatened. This number is likely an underestimate as many ecological communities lack available robust long-term data to facilitate assessment. Aims and methods Using insights from a range of research studies and long-term monitoring in the Mountain Ash (Eucalyptus regnans) forests of the Central Highlands of Victoria, we examine evidence for its listing as a Threatened Ecological Community. Key results The structure and composition of the Mountain Ash ecological community and the key ecological processes that underpin its integrity have been radically altered in the past century. The community is extensively degraded, heavily fragmented, and suffering substantial biodiversity loss. It should be listed as a Threatened Ecological Community under the EPBC Act. Conclusions and implications Insights from long-term ecological monitoring and other studies provide a strong case for listing the Mountain Ash forests of the Central Highlands of Victoria as a Threatened Ecological Community. The community meets four of the six criteria for listing as a threatened ecological community. Under those four criteria, the Mountain Ash forest community should be listed as either Endangered or Critically Endangered.

What did it used to look like? A case study from tall, wet mainland Mountain Ash forests prior to British invasion

“…Like old‐growth forests, multi‐aged stands are now comparatively rare (Lindenmayer et al., 2023), but historical evidence, coupled with simulation modelling, indicates they were much more common in the past (Lindenmayer & McCarthy, 2002). Large, dead, and fire‐killed trees that remain standing after a wildfire provide an evidence of their standing condition at the time of the fire in Mountain Ash forests.…”

“…These forests feature key overstorey tree species such as Mountain Grey‐gum ( Eucalyptus cypellocarpa ), Messmate Stringybark ( Eucalyptus obliqua ), Alpine Ash ( Eucalyptus delegatensis ), and Mountain Ash ( Eucalyptus regnans ) (DEECA, 2023). In particular, we have focused on the Victorian Mountain Ash forests within the Wet and Damp Forest Ecological Vegetation Classes (EVCs) (sensu DELWP, 2018), where there has been extensive scientific research and monitoring over the past 60+ years (e.g., Ashton, 1981b; Lindenmayer, 2009), and especially in the Central Highlands region of that state (Lindenmayer et al., 2023). There have been conflicting historical accounts of the condition of Mountain Ash forests prior to the British invasion, with some accounts claiming that these forests in many areas were open (Gammage, 2011; Howitt, 1890) and regularly burnt by First Nations People (Pascoe, 2018; Pascoe & Gammage, 2021), while others claim that systematic burning of these forests by First Nations People was unlikely (Griffiths, 2002).…”

“…First, some researchers have argued that the high‐nutrient soils that support Mountain Ash forests were semi‐cleared and open to enable them to be used for agriculture by First Nations Peoples (Pascoe, 2018; Pascoe & Gammage, 2021). Second, Mountain Ash forests have had a long history of intensive logging and wildfire and are now extensively degraded (Lindenmayer et al., 2023). Information on the historical structure and composition of these forests may help guide how they might be best restored in the future, including following the cessation of industrial logging operations in eastern Victoria in January 2024.…”