Post-fire recruitment and resprouting of a threatened montane eucalypt.

Changing climate is predicted to result in increased frequency and size of wildfires in south-eastern Australia. With increasing area burnt there is increased potential for entire species distributions to be burnt in a single fire event. This is particularly the case for range-restricted threatened species. Eucalyptus canobolensis (L.A.S.Johnson & K.D.Hill) J.T.Hunter is restricted to Mount Canobolas, New South Wales, Australia. In 2018, the majority of the E. canobolensis population was burnt by wildfire. One-year post-fire, we measured recruitment, resprouting and mortality of E. canobolensis. At higher fire severities, smaller trees were more likely to resprout from their bases only, as their stems were killed (i.e. 'top kill'). Seedling regeneration only occurred in burnt plots. Our study demonstrates that E. canobolensis has a fire response typical of many eucalypts, characterised by seedling recruitment and larger trees resprouting epicormically, even after high-severity fire. Nevertheless, E. canobolensis response to repeat and short-interval fire remains unknown, and smaller trees appear to be vulnerable to top kill. Although much of Australia's flora can respond to fire, this response is likely to be challenged as fire extents increase, especially if this is combined with increasing fire severity and/or frequency. These changes to the fire regime are a particular threat to species with restricted distributions. In 2018, wildfire burnt 70% of the Mount Canobolas State Conservation Area and the majority of the population of the Endangered endemic tree Eucalyptus canobolensis. The species is regenerating from resprouts and seedlings; however, severe fire has limited smaller trees to resprouting from their bases only – indicating that short-interval, severe fire has the potential to suppress entire generations of E. canobolensis. Wildfires are predicted to become larger, more severe and more frequent with climate change, and this this is of particular concern for range-restricted threatened species. [ABSTRACT FROM AUTHOR]