The subalpine and alpine environments of mainland south-eastern Australia which regularly experience annual winter snow comprise approximately 5200 sq. km, equating to less than 1% of the continent as a whole. Although small in area, their true significance can be ascertained by their importance as water catchment areas, and the presence of many rare and threatened flora and fauna. Like alpine regions all over the world, the Australian Alps are increasingly in danger of the many effects of a changing climate, and particularly that of global warming. However, the flora and fauna of the Australian Alps face an increased risk when compared to other alpine regions due to the relatively small size of alpine and subalpine habitat, and therefore the reduced capacity of our flora and fauna to migrate to more suitable habitats within the mountain range.
Although it is possible to identify broad patterns of change, of less certainty is the response of key subalpine and alpine species to both the direct and indirect influences of current and potential future climate change. My research involves a novel approach combining species distribution modelling techniques, with a suite of field based experiments evaluating predicted model output accuracy. It is hypothesized that temperature alone will not limit the presence and distribution of alpine herbs above and below the treeline. However, the indirect consequences of warming, leading to a shift in the altitudinal position of the treeline, and encroachment of subalpine flora into the alpine zone, increasing competition for light resources, may have a significant effect in determining the future distribution of alpine flora.
Additional focus will be on the dynamics influencing the current position of the treeline, and the ability of the treeline species, Eucalyptus pauciflora to recruit above the current subalpine boundary, under current and future conditions. The extinction risk of rare and endemic alpine flora under altered future conditions will be quantified, as will the inherent variability within alpine species across altitudinal gradients, potentially leading to increased resilience to warmer temperatures, and invasion of subalpine flora into the previously uninhabited alpine zone. Furthermore, the relevance and validity of using distribution and bioclimatic models to predict current and future species distributions and responses at small and large scales will be considered.
