On the surface marine animals such as reef corals and plant species like eucalypts sound very different.
Sure they are both iconic Australian species but could they really end up being best mates in the fight against climate change?
“You betcha,” according to native forest specialist Dr Trevor Booth from CSIRO and coral researcher Dr Paul Muir from the Museum of Tropical Queensland.
The scientists have teamed up to highlight these important Australian ecosystems and their similarities in biology and vulnerability to rapid climate change.
Their paper Climate change impacts on Australia’s eucalypt and coral species: Comparing and sharing knowledge across disciplines has been published in the online journal WIREs Climate Change.
Same, same but different
There are many similarities in the biology of eucalypts and corals. They are both long-lived, unmoving organisms that can reproduce asexually, but also sexually by broadcasting very large quantities of tiny offspring. Corals are the most plant-like of all animals, deriving much of their energy from photosynthesis via microscopic algae that live symbiotically within their tissues. But perhaps most importantly, eucalypts and reef corals are the key foundation species in their respective ecosystems, providing much of the framework that hundreds of thousands of other species rely upon.
“Losing these key foundation species would be catastrophic for many of our most diverse ecosystems,” Booth said.
“Coral is the more vulnerable of the two groups when it comes to climate change but both collections of species have been and will be significantly affected.”
The impact of climate change
Eucalyptus trees and reef corals are on the front line of many climate change impacts. Just in the past six months, eucalypts have suffered heavy losses from the catastrophic 2019-2020 Australian bushfires linked to extreme climate events. Corals have suffered mortalities from moderate to severe coral bleaching associated with unusually high seawater temperatures on the Great Barrier Reef.
“By comparing research efforts, eucalypt and reef coral workers might benefit from each other’s experiences,” Muir said.
“Researchers are putting huge efforts into understanding these threats, likely future changes and how we can manage these systems to prevent species extinctions.”
One example where knowledge could be usefully shared is in the prediction of changes to species distributions that will occur from climate change impacts.
How are a plant and animal species going to help each other to fight climate change?
CSIRO researchers made pioneering advances in developing species distribution modelling or SDM, which determines how environmental factors such as mean annual temperature and rainfall of the driest quarter shape a species distribution. More recently, eucalypt researchers from various agencies have predicted likely future changes in species distribution under various climate change scenarios. These results are critical for managing ecosystems, for example by identifying particularly vulnerable species and tailoring management responses to prevent species declines. Researchers have spent many years working collaboratively with other colleagues and institutions developing the large datasets of species distributions and environmental conditions that are required for SDM analyses. In contrast, SDM analyses have only rarely been used in coral research but could provide important information for managing the future of reefs.
“I am hoping the work we have done with eucalypts can help coral researchers benefit from these methods and avoid some of the traps,” Booth said.
Four key areas of research Booth and Muir considered in the journal article were:
(1) modelling current distributions,
(2) assessing impacts of climate change on future distributions,
(3) using human-assisted migration to improve survival and
(4) applying genetic enhancement to improve species’ survival.
With many years of examining the climatic tolerances of eucalypts, it is not surprising that experience from eucalypt studies may have more to offer climate change studies of corals than vice versa. However coral studies are successfully and rapidly applying novel spatial, controlled environment and genomic methods to assess how coral species may adapt to changing climatic conditions.
Drawing on existing data bases
For their research, the authors extensively used the Atlas of Living Australia that provides an online repository for both terrestrial and marine data along with a suite of tools to analyse these data.
“The marine section of the data base is not used as much as it could be so it would be great if our journal article prompts more coral researchers and community members to use it and enhance existing datasets of coral species distribution and environmental conditions,” Booth said.
The Atlas of Living Australia also supports and integrates the extensive national citizen science community into its data system.
Two unlikely fellows
Booth and Muir, and the partnership they formed for their research, was almost as unlikely as their subject matter.
“I was listening to the ABC ‘Science Show’ in February 2019 and they had a program on coral spawning and assisted evolution work taking place at the Australian Institute of Marine Science (AIMS) in Townsville,” Booth said.
“I thought to myself ‘that’s an awful lot like the work we are doing with eucalypts’ and that prompted this exchange of ideas.”
Booth got in touch with a contact at AIMS who introduced him to Muir at the Museum and the collaboration began. All three organisations contributed to some early discussions relevant to the final journal paper.
“At first I thought it was a bit of a strange idea, but I soon realised the potential of the research. And I do take an interest in trees as I live on a large property,” Muir said.
“I’m very fortunate Paul was willing to continue,” Booth joked.
However the partnership came about, both scientists agree “there’s a lot to be learnt from looking outside the box of one’s own research area”.