By Lucy Cormack
13 January 2014
(Sydney Morning Herald) – Australia's standing as the home among the gumtrees could be challenged, with increased climate stress causing extensive change to Australia's eucalypt ecosystems.
A study by the National Environmental Research Program's Environmental Decisions Hub has found that climate stress on eucalypts will mean many of Australia's 750 species will struggle to cope with climate change.
''Those that will be most affected are the Eucalyptus and Corymbia species in the central desert and open woodlands area,'' said author Nathalie Butt of the NERP Environmental Decisions Hub and the University of Queensland.
The study found that ''under the mid-range climate scenario, these species will lose 20 per cent of their climate space, and twice that under the extreme scenario''.
The mid-range scenario suggests that ''temperatures will increase by more than 1C by 2055 and by more than 2C by 2085. For the extreme scenario temperatures will increase by more than 1.5C and 2.5C respectively'', Dr Butt said. She said there is additional concern for the impact these conditions will have on wildlife in such areas. ''Trees are habitats and food sources. So this will have a cascade effect on birds, bats, and invertebrates that are reliant on eucalypt, and it will affect pollinators as well,'' she said. [more]
ABSTRACT: Global climate change is already impacting species and ecosystems across the planet. Trees, although long-lived, are sensitive to changes in climate, including climate extremes. Shifts in tree species' distributions will influence biodiversity and ecosystem function at scales ranging from local to landscape; dry and hot regions will be especially vulnerable. The Australian continent has been especially susceptible to climate change with extreme heat waves, droughts, and flooding in recent years, and this climate trajectory is expected to continue. We sought to understand how climate change may impact Australian ecosystems by modeling distributional changes in eucalypt species, which dominate or codominate most forested ecosystems across Australia. We modeled a representative sample of Eucalyptus and Corymbia species (n = 108, or 14% of all species) using newly available Representative Concentration Pathway (RCP) scenarios developed for the 5th Assessment Report of the IPCC, and bioclimatic and substrate predictor variables. We compared current, 2025, 2055, and 2085 distributions. Overall, Eucalyptus and Corymbia species in the central desert and open woodland regions will be the most affected, losing 20% of their climate space under the mid-range climate scenario and twice that under the extreme scenario. The least affected species, in eastern Australia, are likely to lose 10% of their climate space under the mid-range climate scenario and twice that under the extreme scenario. Range shifts will be lateral as well as polewards, and these east–west transitions will be more significant, reflecting the strong influence of precipitation rather than temperature changes in subtropical and midlatitudes. These net losses, and the direction of shifts and contractions in range, suggest that many species in the eastern and southern seaboards will be pushed toward the continental limit and that large tracts of currently treed landscapes, especially in the continental interior, will change dramatically in terms of species composition and ecosystem structure.