Project funded by the Australian Research Council - Discovery Project (2016-2018)
Tropical savannas dominate the landscapes of northern Australia and cover almost a quarter of the continent. The intensification of primary industries in the north is a government imperative. Human population growth, especially in Asia, is intensifying pressure for grazing, food and fibre production in these relatively pristine savanna landscapes. Such land-use change (LUC) will have profound implications for the carbon and water cycles of these monsoonal, highly seasonal, flood-pulse driven ecosystems. The potential consequences include alteration of regional carbon sink strength and reduction in groundwater and river water quality. There is therefore an urgent need for research focussing on the sequestration and export of water and carbon from terrestrial to aquatic ecosystems, and their subsequent storage and release into oceans and the atmosphere. This project builds on two decades of investment in understanding biogeochemical cycling in northern Australian tropical savannas, and the impact of disturbance on these systems. We will deploy established and newly developed, state-of-the-art, biogeochemical and isotopic techniques to achieve the following aims:
Aim 1 - Quantify the carbon and water cycle impacts resulting from the conversion of mixed C3/C4 native savanna to both C4 dominant pasture and C3 dominant forest plantation.
Aim 2 - Close the natural savanna carbon budget by quantifying a hitherto unrecognised, but now demonstrably significant ‘missing sink’ - lateral export of organic and inorganic carbon to rivers from ‘leaky’ savanna soils during the wet season.
Aim 3 - Model carbon fluxes and reservoirs in northern savannas to explicitly predict changes in carbon stocks under various LUC scenarios.
- Prof Michael Bird, James Cook University (webpage)
- A/Prof Jonathan Wynn, University of South Florida (webpage)