Geochemical exploration of environmental controls on the Australian flora
This project will use carbon isotope ratios of plants to identify their photosynthetic pathway and map their geographic distributions to better understand the main environmental controls on their biogeography.
Today, 70% of Australia is covered by native grassland, shrubland and savannah, dominated by plants that use C4 photosynthesis, while only 20% is native forest dominated by plants that use C3 photosynthesis. C3 photosynthesis occurs in all trees, temperate grasses and most shrubs. C4 plants are predominantly (80%) grasses and sedges (>6000 species), but there is a also a high diversity (>500 species) of C4 chenopods (Amaranthaceae; e.g. the widespread Atriplex or saltbush).
C4 plants are highly competitive in hot, saline and seasonally arid conditions, with summer rainfall regimes strongly favouring C4 grasses in Australia. Fire also plays a larger role in maintaining C4 dominance in savannah by eliminating C3 trees saplings. However, the specific factors that control the distribution and dominance of C4 plants is not entirely known and is the focus of this project.
This project will partner with the Terrestrial Ecosystem Research Network (TERN) to use carbon isotope ratios of modern collections of plants and soils to determine how the geographic coverage of C3 versus C4 plants relates to climatic and environmental (e.g. fire, land use) factors.
This work will promote the future management of these ecosystems in a changing environment
- A background in ecology, palaeontology and/or earth sciences