Abstract
The effects of climate change, particularly altered rainfall patterns, are apparent across Australia. In Southwestern Australia, a biodiversity hotspot, decreased annual rainfall is causing concern for the persistence of native flora. The ability of Australian species to rapidly select for drought tolerance in response to decreased rainfall is largely unknown, yet this knowledge is required to develop future management and conservation strategies. This research aims to determine whether seed-banks of selected species can potentially mitigate effects of a drying climate through rapid selection and adaptation. It is hypothesised that the seed-bank of a species can increase resilience to climate change by providing a range of genetic material for rapid selection.
Eight locations where fire was followed by a wet, dry or average winter were identified at Eneabba, Southwestern Australia. At each location, seed was collected from five serotinous, fire-killed species; Banksia hookeriana, Banksia leptophylla, Hakea costata, Hakea polyanthema and Beaufortia elegans. Seed was germinated, and divided into three drought treatments: 100%, 75%, and 50% mean winter rainfall equivalent. Post-spring, seedlings will be harvested and dry-weight of roots/shoots determined.
A larger proportion of seedlings descended from plants recruited post-fire in dry winters are expected to exhibit tolerance to drought treatments than those descended from plants recruited in average or wet winters.
This experiment is part of a broader study on evolutionary adaptation in Western Australian species, which aims to determine the ability of species to rapidly evolve in response to climate change, and assist in informing approaches to adaptive conservation management.