Resilience: Can our environment keep bouncing back?

3 May 2011

You may have heard of the environment 'bouncing back' quickly from a disaster. But how much can our environment take?

The Victorian Bushfires in summer 2009 provide a stunning example of the ability of natural ecosystems to recover following disturbance. Dr Margaret Barbour and her team from the Faculty of Agriculture, Food and Natural Resources, at the University of Sydney, visited the aptly named Mt Disappointment in Victoria's bushfire ravaged mountain region. What they found was incredible.

"Australian forests are well known to be highly fire-adapted," Dr Barbour commented. "Eucalyptus regnans regenerates only from seed after fire. The Black Saturday bushfires burnt large areas of E.regnans forests in Victoria, and a mass germination occurred beneath the blackened stems. We found seedlings up to three meters tall, with up to one million stems per hectare."

The ability of a system to return to its normal state is termed "resilience". Systems can be resilient to both positive and negative forces and recover either rapidly or gradually. Questions surrounding the ability of natural, economic and social systems to function within their current state despite climate change, political shifts and environmental degradation, will be examined at the ground-breaking symposium "Resilience: can our environment keep bouncing back?" at the University of Sydney this year.

Associate Professor Michael Harris is a speaker at the Symposium and resilience researcher in economics in the Faculty of Agriculture, Food and Natural Resources at the University of Sydney. His research is pioneering the study of ecosystem "tipping points", and what this implies for accounting, management and policy.

"Environmental economists are well practised at evaluating the incremental impacts of incremental human actions," Associate Professor Harris explained.

"What resilience thinking does for economists is focus on cases where incremental changes have minor effects on an ecosystem up to a point, but the cumulative effects of those changes can eventually have major - perhaps disastrous—impacts."

Historically, we know the survival of natural systems has been intertwined with the survival of societies. In popular culture, there has been a recent surge in the number of Hollywood films which depict disastrous crashings of natural systems. Futuristic films aside, how much disturbance can real natural systems endure in the modern world? Do we need to fear a sudden global crisis?

Take food production as an example. "Agronomy - the science and technology of producing crops - is without question one of the most important human endeavours," said Professor Jeff Amthor, a biological scientist and Symposium speaker from the Faculty of Agriculture, Food and Natural Resources, and expert in the limits of plant productivity.

"The vast majority of the 6.9 billion people now alive rely on agronomy daily, and whereas political, social, and economic systems can - and do - interrupt the flow of agronomic outputs to their intended recipients, agronomy has proven itself time after time," said Professor Amthor.

Associate Professor Harris believes that hope in our continued ability to produce food depends on whether people make wise decisions.

"Our study of a productive agricultural catchment in Victoria showed changes in the risk of the whole catchment becoming unproductive as human management decisions caused the water table to rise, slowly but surely. The functioning of the system - its productivity - changed little, but what was important was that its resilience was being continuously reduced," said Associate Professor Harris. "It was drought that kept the water table out of the danger zone, not prudent human management."

"Our understanding of management practice and policy design needs to be informed about how to manage systems to maintain their resilience, and the costs and trade-offs of doing exactly that."

Researchers believe there is good reason to study resilience in both economics and science. By understanding resilience, not only are we able to stay within a system's limits, but in some cases we can enhance its ability to bounce back. A system's ability to bounce back determines how durable the system remains under our increasingly affluent and populous world - and whether the system can endure at all.

What does a truly resilient system look like? Perhaps we should take a lesson from the recovering forests of Victoria.

"Two years after the fire, in late February this year, we investigated carbon cycling in the regenerating stand," said Dr Barbour. "Variation in stable carbon isotopes as environmental conditions changed allowed us to show the very rapid cycling of carbon from the canopy, transfer of synthesised carbohydrates through the seedlings, and eventual release of CO2 back to the atmosphere three days later."

If a plant, forest and whole ecosystem can regrow this rapidly, surely there is hope for our modern world. This exciting subject will be the topic of discussion at the Faculty's annual Research Symposium, 8th July 2011.

Resilience: can our environment keep bouncing back?

Date: 8.30am - 6.00 pm, Friday 8th July 2011

Venue: Lecture Theatre 101, New Law Building, University of Sydney

Guest Speakers include:

Professor Mary O'Kane, NSW Chief Scientist

Professor R. Quentin Grafton, Director, Centre for Water Economics, Environment and Policy (CWEEP) , Convenor, Environmental and Resource Economics (GDERE & MERE) degrees, The Australian National University

Professor Karl-Göran Mäler, The Beijer Institute of Ecological Economics, The Royal Swedish Academy of Sciences

Dr Jayne Belnap, Research Ecologist, United States Geological Survey, President-Elect of the Soil Ecology Society

All welcome. For more information or to register online

Contact: Lucy Buxton

Phone: 02 8627 1005

Email: 5f1c16307e15454c12062f76201e502a3203765d1c0174133e