Botanic gardens may be nice places for walks or picnics but they're also playing an important role in combating climate change.
The green spaces in Australia and around the world give scientists important information on how a warming climate is affecting plant species, University of Melbourne Professor David Karoly says.
"They're able to monitor these sorts of changes in that plant behaviour, what's called the timing of seasonal events like when plants flower or when they produce seed," Prof Karoly told AAP.
"They can monitor how things have changed over the last 50 or 100 years, completely separate from temperature observations or rainfall observations."
Cities can control the water supply to plants in botanic gardens through irrigation systems but the temperature is harder to control, Prof Karoly said.
With increasing heatwaves and hotter weather due to climate change, the professor said botanic gardens are not only acting as monitors but are also becoming increasingly vital to populations in built-up cities.
"If there's much more natural vegetation, and if we increase the amount of natural plants, then that reduces the temperature," he said.
"Heat waves are modified in natural environments so it's really important that we use botanic gardens as ways to illustrate the benefits of increasing and maintaining more vegetation."
Prof Karoly will be talking about the role of botanic gardens in climate change at the Global Botanic Gardens Conference meeting in Melbourne this week.
About 500 delegates from more than 40 countries are converging on the Victorian capital after last year's event was cancelled due to COVID-19.
They will participate in field trips to Melbourne's Royal Botanic Gardens and other botanic gardens in the state, before engaging in talks and workshops at the Melbourne Convention and Exhibition Centre.
The conference will explore how gardens are at the forefront of knowledge and research, Botanic Gardens Conservation International Secretary General Paul Smith said.
"The world's botanic gardens grow over 120,000 different species of plants, including around 18,000 tree species," he told AAP.
"This knowledge is essential for human adaptation to climate change, from planting trees for carbon sequestration to growing new food plants and cultivars for food security.
"Botanic gardens collectively receive over 750 million visitors each year so they also have a huge role to play in raising awareness about issues such as climate change as well as demonstrating solutions for sustainability."
The global conference runs from Sunday to Thursday.
