Climate stress is increasing for Australia’s iconic eucalypts

Background/Question/Methods

Australia is particularly vulnerable to climate change with large parts of the continent predicted to experience hotter than average temperatures, more rainfall, and more frequent and severe droughts. Almost all forests across Australia are dominated by the eucalypt clade (genera Eucalyptus, Angophora, and Corymbia). We asked how the changing climate might affect eucalypt species across the continent by modelling a representative sample of Eucalyptus and Corymbia species (> 10% of all species) using Maxent and newly developed RCP climate scenarios (Representative Concentration Pathway scenarios developed for the 5^th Assessment Report of the IPCC), and bioclimatic and substrate predictor variables. 

Results/Conclusions

Eucalyptus species in the central desert and grassland regions were the most affected, losing 20% of their climate space under the mid-range climate scenario and 40% under the extreme scenario. Species in the eastern part of the continent will be least affected, losing 10% of their climate space under the mid-range climate scenario and 20% under the extreme scenario. Future range projections indicate species climate niches on the eastern and southern seaboards will shift towards continental limits. Changing climatic conditions do not necessarily translate to species range shifts or declines, but they do suggest that species across the continent are likely to experience substantially different climates in the coming years. Globally, this has implications for many subtropical and savanna regions with seasonally variable rainfall.