Abstract ID: 3.12621 | Accepted as Talk | Talk | TBA | TBA

Globally, alpine ecosystems are experiencing increasing temperatures, earlier snowmelt, and extreme water deficits in summer. The rapid hydrological changes that are taking place in alpine environments are a major threat to plants that require stable water supply to survive. In the Australian alps, groundwater-fed ecosystems support a unique suite of plant species, many of which are rare and/or threatened. Such areas may become uninhabitable as hydrological regimes change, leading to the loss of potentially important populations through recruitment failure. Intraspecific variation in germination characteristics and seedling establishment traits may provide species with greater resilience to environmental change and help to mitigate extinction risk. Identifying patterns of variation in recruitment traits at the population level can inform conservation efforts by highlighting important insurance populations. In two experiments we examine intraspecific variation in recruitment traits relating to duration of snow cover (using 0-12 week treatments in moist cold stratification), water availability (using sand saturated with polyethylene glycol solutions of different concentrations) and warming in Psychrophila introloba (Ranunculaceae), Drosera arcturi (Droseraceae) and Oreobolus pumilio subsp. pumilio (Cyperaceae) all of which are foundational to high elevation gravelly herbfields – a rare and range-restricted spring-fed plant community found in the Australian alps. Between populations of the same taxa we found considerable variation in germination rates following different cold stratification periods. Overall, seed germination was delayed under drier treatment, faster in the warmer treatment and seedling biomass was reduced under drought. Germination strategies and seedling establishment traits varied considerably in response to drying and warming both between and within species, thus indicating that certain populations may be better adapted to future conditions and deserve special attention in conservation actions.