A new study led by researchers from Royal Botanic Gardens Victoria and Deakin University has uncovered alpine species may be more vulnerable to climate change as their seeds rely on specific temperature cues and seasonal signals to germinate.
The team examined seeds from 21 Australian plant species, including Eucalyptus pauciflora subsp. acerina (Alpine Snow Gum), Callistemon kenmorrisonii (Betka bottlebrush), Brachyscome decipiens (common alpine daisy), collected across a dramatic elevation range, from near sea level to alpine regions.
The research found that elevation plays a key role in shaping seed behaviour as it shapes both dormancy (whether seeds delay germination) and the temperatures at which they will sprout.
Seeds from alpine and subalpine species were more likely to remain dormant, requiring specific cues before they would germinate. Even when conditions were suitable, these species showed a preference for warmer temperatures between 20 and 30 degrees Celsius and performed poorly at cooler temperatures. This narrow temperature range suggests they are highly specialised and have likely evolved to avoid germinating too early when frost or snow could kill young seedlings.
By contrast, seeds from lowland species were far more flexible. Many showed little or no dormancy and were able to germinate across a wide range of temperatures, including cooler conditions. This broader tolerance suggests these species are adapted to more variable environments, where timing is less tightly constrained.
"While some species show remarkable flexibility, many alpine plants are highly specialised. Understanding these differences is key to protecting them as the climate continues to change," said Dr Megan Hirst, Research Scientist (Seed Ecology) at Royal Botanic Gardens Victoria.
"These differences have major implications as the climate changes. Alpine species rely on specific environmental signals, such as temperature patterns and seasonal cues, to determine when to germinate," says Dr Hirst. "As warming temperatures and declining snow cover alter these signals, seeds may begin to germinate at the wrong time, reducing their chances of survival. This could lead to mismatches between when seeds germinate and when conditions are suitable for growth, placing additional pressure on already vulnerable alpine ecosystems."
Not all plant groups responded in the same way. Some, including certain Eucalyptus species and alpine grasses, showed strong dormancy patterns linked to elevation, while others—such as bottlebrush species in the genus Callistemon—showed no dormancy at all, regardless of where they grew. A third group of native daisies displayed mixed responses, with variation not only between species but even between populations of the same species.
This variation highlights the complex interplay between evolutionary history and local environmental conditions. Even within a single species, seeds collected from different locations responded differently depending on factors such as moisture and microclimate. In some cases, offspring from plants grown in new environments showed changes in germination behaviour, suggesting a capacity for adaptation across generations
The findings are particularly important for conservation and restoration efforts. Understanding how seeds respond to temperature can help identify which species are most at risk from climate change and guide decisions about when and where to use seeds in restoration projects. The research also reinforces the importance of seed banking, with many seeds in the study successfully germinating even after more than a decade in storage at the Victorian Conservation Seed Bank.
As climate change continues to reshape ecosystems, the timing of germination—one of the earliest stages of life—may ultimately determine which species persist and which decline. The study reveals that while some plants may have the flexibility to adapt, others, particularly those in alpine environments, may be running out of time.
