Skip to menu Skip to content Skip to footer
News

Frost risk predicts leaf size worldwide

1 September 2017
Key factors affecting leaf size were night temperatures and risk of frost damage
Key factors affecting leaf size were night temperatures and risk of frost damage

Why is a banana leaf a million times bigger than a common heather leaf? And why are leaves generally much larger in tropical jungles than in temperate forests and deserts?

A global team of 17 scientists including a University of Queensland researcher has cracked the mystery of why plant leaves vary wildly in size.

UQ School of Biological Sciences postdoctoral fellow Dr Elizabeth Law said it was a century-old conundrum for scientists as to why leaf size varied with latitude – from very small near the poles to massive leaves in the tropics.

“While the textbooks say it’s a balance between water availability and overheating, we just didn’t see that in the data,” she said.

Decorative

The research, led by Associate Professor Ian Wright from Macquarie University, revealed that in much of the world, key factors affecting leaf size were night temperatures and risk of frost damage to leaves.

The international team of researchers analysed leaves from more than 7600 species across the world.  The data was teamed with new theory to create a series of equations which predict the maximum viable leaf size anywhere in the world based on the risk of daytime overheating and night-time freezing.

Decorative

Decorative
The researchers will use these findings to create more accurate vegetation models. These will be used by governments to predict how vegetation will change locally and globally under climate change, and to plan for adaptation.

Dr Law said it was exciting to be part of a team that has developed new theories in ecology.

“Not just observing patterns and changes, but really being able to explain why they happen,” she said.

“It’s the first step towards better predictions of the future.”

Decorative
The study is published as the cover story in the latest edition of Science.  

Media: Dr Elizabeth Law, e.law@uq.edu.au, +61 7 336 52527 or Niall Byrne, niall@scienceinpublic.com.au, +61 417 131 977.

Related articles

Three researchers wearing blue protective lab gowns stand among rows of potted chickpea plants inside a controlled-environment plant research facility.

Turning up the heat on chickpea yield

A University of Queensland study has outlined a practical pathway for accelerating the development of heat adapted chickpeas using data from new ‘omic’ technologies. PhD candidate Callum Jamie said the suite of technologies offered tremendous opportunities to understand how a complex trait like heat tolerance works. “The narrow genetic diversity in the elite chickpea gene pool has limited conventional breeding’s effectiveness for stress tolerance,” Mr Jamie said. “These technologies have improved our capacity to dissect trait architecture and phenotype secondary traits but their use in chickpeas has been limited.” The technologies include genomics, epigenomics, transcriptomics, proteomics, metabolomics, phenomics and enviromics, and help provide a comprehensive picture of biological systems. Epigenomics helps understand what controls gene activity; transcriptomics considers gene expression; proteomics protein production; metabolomics looks at biochemical processes; phenomics observes traits; and enviromics considers environmental factors influencing outcomes. Mr Jamie said previous studies had focused on just 1 to 2 -omic datasets, a small number of genotypes, and single tissues. This has meant it was hard to infer what results meant for trait architecture and mechanisms and the ability to extrapolate the information to breeding populations was limited. There have also been challenges around cost, scalability and integrating very different types of data to make the technologies useful. To overcome the hurdles, Mr Jamie’s research at the Queensland Alliance for Agriculture and Food Innovation has resulted in a proposed staged approach. It would start with genomic prediction and phenotyping, before adding -omic layers as costs fall and unknowns were resolved. “These technologies are novel and we still don’t know which information provides added value and how best to integrate all of this data to achieve an outcome,” Mr Jamie said. His PhD is supported by the Grains Research and Development Corporation (GRDC) and the International Research Training Group (IRTG) Accelerating Crop Genetic Gain and is aligned to a project which aims to fast-track the development of chickpea varieties adapted to high temperatures. Project leader Dr Millicent Smith said heat stress causes severe yield implications through flower and pod loss, reduced pollen viability and impaired grain filling. “Late sown chickpea is particularly in the firing line across most of Australia's crop in southern Queensland and northern New South Wales,” Dr Smith said. “We want to ensure that Australian growers maintain their competitive edge. “New varieties with improved genetics to cope with heat stress are essential for the future. “This work, suggesting a staged approach to utilising the new -omic technologies, is an exciting frontier.” The research was published by Food and Energy Security. Callum Jamie’s PhD is supported by the Grains Research and Development Corporation (GRDC) and the International Research Training Group (IRTG) Accelerating Crop Genetic Gain.
15 October 2026
Close-up photograph of a red-bellied black snake coiled across pale, weathered wood. The snake has glossy black scales on its back and vivid red coloration along its sides and underside. The image highlights the texture of the scales and the contrast between the dark body and the light wood background.
Analysis

Deadly fungi are harming Australia’s wild reptiles. This is how to stop the spread

With spring underway and the weather warming, reptiles are on the move in suburbs, parks and bushland across Australia. Snake catchers and wildlife carers are responding to calls for help, and reptile enthusiasts – known as “herpers” – are heading outdoors in search of their next sighting.
13 October 2026

Media contact

Subscribe to UQ News

Get the latest from our newsroom.