Which trees will survive climate change?

JCU’s Professor Lucas Cernusak will lead the study, funded by a more than $700,000 grant from the federal government’s Australian Research Council.

He said atmospheric carbon dioxide has increased by 50% globally, driven by human activity from around the year 1750 as the industrial revolution began.

“While this has caused global warming and climate change, atmospheric carbon dioxide also provides the fuel for plant growth. Its rise has likely resulted in increased growth of tropical forest trees, but we don’t know which tree species benefit most,” said Professor Cernusak.

He said preliminary observations suggest tropical conifer trees (cone-bearing seed plants such as pines) benefit more than angiosperms (flowering plants such as eucalyptus).

“In this project, we will identify the underlying physiological processes that allow some tropical tree species to increase their growth rates more than others in response to rising atmospheric carbon dioxide,” said Professor Cernusak.

The team will grow plants in soils of both low and high fertility and at different CO₂ levels.

Leaf gas exchange analysis of tropical conifers and angiosperms will be conducted and leaf material will be analysed for nitrogen concentrations and stable isotope ratios of carbon, nitrogen and oxygen.

Core samples will be taken from mature trees growing on the Atherton Tablelands.

“We will use this information to develop a model that can satisfactorily reproduce the observed trends over time, then use it to project future trends in respect to atmospheric CO₂ concentration and climate change – in Queensland and in tropical forests globally.”

He said the information will benefit many.

“Being able to better predict tree responses to the inexorable rise in atmospheric carbon dioxide will benefit the Australian forestry sector, natural resource managers, conservation practitioners and policy makers aiming to maximise carbon sequestration,” said Professor Cernusak.