Climate change and long-term fire management impacts on Australian savannas.
Tropical savannas cover a large proportion of the Earth's land surface and many people are dependent on the ecosystem services that savannas supply. Their sustainable management is crucial. Owing to the complexity of savanna vegetation dynamics, climate change and land use impacts on savannas are highly uncertain. We used a dynamic vegetation model, the adaptive dynamic global vegetation model (aDGVM), to project how climate change and fire management might influence future vegetation in northern Australian savannas. Under future climate conditions, vegetation can store more carbon than under ambient conditions. Changes in rainfall seasonality influence future carbon storage but do not turn vegetation into a carbon source, suggesting that CO₂ fertilization is the main driver of vegetation change. The application of prescribed fires with varying return intervals and burning season influences vegetation and fire impacts. Carbon sequestration is maximized with early dry season fires and long fire return intervals, while grass productivity is maximized with late dry season fires and intermediate fire return intervals. The study has implications for management policy across Australian savannas because it identifies how fire management strategies may influence grazing yield, carbon sequestration and greenhouse gas emissions. This knowledge is crucial to maintaining important ecosystem services of Australian savannas.
Biodiversity and Climate Research Centre (LOEWE BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325, Frankfurt am Main, Germany.
Simon
S
Scheiter
Department of Botany, University of Otago, Dunedin, 9054, New Zealand.
Steven I
SI
Higgins
School of Geography and Environmental Science, Monash University, Melbourne, Vic., Australia.|School of Earth and Environment, University of Western Australia, Crawley, WA, Australia.
Jason
J
Beringer
Research Institute for the Environment and Livelihoods, Charles Darwin University, Darwin, NT, Australia.
Lindsay B
LB
Hutley
D000349:Africa; D001315:Australia; D018533:Biomass; D057231:Climate Change; D003198:Computer Simulation; D003247:Conservation of Natural Resources; D005390:Fires; D065948:Grassland; D008962:Models, Theoretical; D018526:Plant Transpiration / Q000502:physiology; D045483:Rivers; D013997:Time Factors; D014197:Trees / Q000033:anatomy & histology
Australia; CO2 fertilization; adaptive dynamic global vegetation model (aDGVM); carbon sequestration; climate change; fire; management; savanna