Sowing new seeds of knowledge

Step into the colourful world of UQ's Dr John Dwyer

If you enjoy fresh flowers in your garden, just imagine what it’s like to be surrounded by thousands of them.

For UQ School of Biological Sciences’ lecturer and CSIRO researcher Dr John Dwyer, a field of stunning everlastings is his office – where he works to unlock the drivers of plant diversity.

His latest study of Australian annual wildflower communities has improved the understanding of how climatic stress controls plant diversity, based on the strategies different species use to survive, grow and reproduce.

“Plant diversity tends to be lower in more stressful environments,” Dr Dwyer said.

“However, we have a surprisingly poor understanding of the processes behind this observed pattern.”

Dr Dwyer, and his co-author Professor Daniel Laughlin from the University of Waikato in New Zealand, aimed to advance ecological knowledge to better manage Australia’s unique ecosystems and landscapes through their study.

Western Australia’s world famous fields of wildflowers provided the perfect location to conduct their research which focused on winter annuals and winter growing bulbs.

“We viewed each plant species as a combination of different characteristics, or ‘traits’, that determine how they tolerate stress, obtain resources, grow and reproduce,” he said.

“Using this approach, we studied combinations of traits within natural wildflower communities along gradients of temperature and rainfall in the Western Australian wheat belt.”

The researchers predicted that many species with different combinations of traits should be able grow together in cool, wet areas where conditions are relatively benign.

“As we moved into more arid communities, we predicted that correlations between traits would strengthen, indicating that species need to combine traits in specific, coordinated ways to tolerate the harsher conditions; and indeed that is what we found,” Dr Dwyer said.

“Specifically, in semi-arid communities the height of species was positively correlated with seed mass.

“This makes sense, because growing tall is risky in drier regions, but having larger seeds reduces this risk because they are packed with more resources from the mother plant.”

Dr Dwyer says the study is not only relevant to Western Australian annual wildflower communities; with the next phase of his research set to investigate trait coordination in other systems such as rainforests.

“We also think our approach can be used to identify native plant species that are likely to struggle under climate change, and to select hardy species for restoration projects.”

The study is published in Ecology Letters.