The presence of snow in an alpine landscape essentially determines the start and the end of a relatively short growing season for plants. And so the timing of snowmelt in the alpine zone is critical for many life history processes such as the onset of growth in the summer and phenology; the timing of flowering, seed production, seedling emergence and establishment. As the snow melts in spring, the landscape resembles a mosaic of snowdrifts and snow free areas, and soil moisture is abundant across most of the landscape. At this time, plants are at their more productive - rapidly metabolising and making the most of the favourable, wet and warm conditions. Later in summer however, when the last of the snowpatches have finally melted, drought conditions are often present, and soils can be well below wilting point. Climate change predictions for Australian alpine areas include higher temperatures (in particular higher minimum temperatures) as well as precipitation falling as rain rather than snow. And so the research questions in this project are aimed at identifying some of the existing patterns with soil moisture, as well as using these natural gradients in snowmelt and soil moisture to speculate about how plants may cope in a warmer, drier alpine landscape.
In this project, an essential component will be to quantify the effect of snowmelt timing on soil drought across several snowmelt gradients.
Some potential research questions could then be:
1) How do vegetation patterns reflect the patterns in soil moisture?
2) How much drought can these plants cope with (assessed by measuring PhotosystemII health with a chlorophyll flurometer either in the field or as part of a glasshouse/laboratory experiment)?
3) How is phenology affected by the soil moisture regime?
4) Is the gradient in soil moisture reflected by species leaf traits such as specific leaf area (SLA)?
Project start will be mid-year to make best use of the melting snow (September – October) and the summer field season.