A new framework developed by a group of international researchers will help land managers deal with climate change-driven forest mortality.

Large scale forest die-offs have been associated with drought and heat and pose a global challenge to forest management, said author Dr Katinka Ruthrof, from Murdoch University and Kings Park Science.

Die-offs have been reported from every forested continent, including Australia. In 2011, Murdoch University researchers revealed that more than 16,000 hectares of the Northern Jarrah Forest near Perth, Western Australia, had suddenly collapsed during a particularly dry, hot summer. Banksia and tuart woodlands also experienced serious die-offs at this time.

Subsequent studies on the Northern Jarrah Forest by Murdoch scientists have found that climate change-type drought drives the replacement of large trees with shorter ones, transforming the forest structure.

“We rely on forests for the air that we breathe, for water and timber, carbon storage not to mention their recreational and cultural value,” said Dr Ruthrof. “As such, mass die-offs, like the one we saw in WA seven years ago, are shocking and worrying.

“Sadly, there is a growing consensus among scientists that such events will become more frequent as climate change progresses.

“The future health of the Northern Jarrah Forest will depend on how often, intense and long drought and heatwave events are in the future – and when this forest reaches its thresholds - which we know so little about.”

The overarching goal of the study was to develop a set of research questions and monitoring goals in a framework known as a “state and transition model”. The method has been used by rangeland managers to deal with climate change and problems associated with overgrazing, and helps to develop management actions.

Dr Ruthrof said the framework would also help officials communicate with the public about why forest die-offs occur and as a tool to request needed resources.

“When there are mass mortality events in our forests, the reasons can often be complex with, for example, location in the landscape, and land use also potentially playing roles,” said Dr Ruthrof.

“Not only is our new model flexible to encompass diverse drivers and impacts, it will help land managers be proactive in their approach.”

For their study, the 21 researchers investigated 14 forest die off case studies from Australia, Africa, Europe, South America and North America.

They discovered that despite the diversity of habitat and many differing drivers of ecosystem change in these cases, there were similarities in potential management interventions and actions.

“Although the solutions are often complex, we can use science to underpin good forest management decisions and help minimise the damage caused by mass mortalities,” added Dr Ruthrof.

The research paper, entitled Ecosystem Dynamics and Management After Forest Die-Off: A Global Synthesis with Conceptual State-and-Transition Models was published in the journal Ecosphere. It can be viewed here.