The Australian alpine ecosystem is particularly vulnerable to the effects of climate change. In part, because it covers < 1% of mainland Australia, but also because it has a limited elevational range. Alpine plants therefore have limited options for range migration, therefore the response to climate change is expected to be primarily determined by their ability to survive in situ through local adaptation or phenotypic plasticity. Climate models for this region project increasingly variable precipitation and snow cover, as a result, we expect water use traits and phenotypic plasticity therein to become increasingly important. Currently, plants from lower elevations experience a more variable environment as earlier snow-melt results in more frequent frosts and greater temperature extremes.
Here we are investigating the extent of plasticity and intraspecific variation in water use traits in three Australian alpine herbs; Wahlenbergia ceracea, Aciphylla glacialis and Oreomyrrhis eriopoda. We are assessing whether patterns of morphological and physiological plasticity differ between species, or between elevations within species under two contrasting glasshouse water treatments. Based on previous studies, we hypothesize that plants from lower elevations will exhibit characteristics consistent with greater plasticity in water use traits.