The University of Western Australia has played a pivotal role in a new international study that reveals climate change is driving significant transformations in the plant composition and ecological functions of California’s grasslands.
The review, published in Nature Ecology and Evolution, focused on grasslands in the California Floristic Province and used extensive long-term observations to detect shifts in species composition related to climate change.
The study’s lead authors, Associate Professor Kai Zhu and postdoctoral fellow Yiluan Song from the University of Michigan, said the research showed grasslands were responding to climate change almost in real time.
Emeritus Professor Richard Hobbs from UWA’s School of Biological Sciences contributed crucial long-term data, collected over several decades, to the study, which showed grassland communities were shifting towards species associated with warmer and drier conditions.
“These changes are occurring at a rate comparable to the pace of climate warming and drying, highlighting the rapid response of these ecosystems to changing environmental conditions,” Professor Hobbs said.
Image: Emeritus Professor Richard Hobbs among the grasslands in the California Floristic Province.
The study analysed 15 long-term community composition datasets from 12 observational studies and three global change experiments and estimated the climate niches of 349 species from more than 829,000 event logs.
The shifts towards species adapted to warmer and drier climates were consistent across both observations and experiments, contrasting with lagged responses observed in forest communities dominated by long-lived plants.
Professor Hobbs, who undertook a postdoctoral fellowship at Stanford University from 1982 to 1984, established experimental plots at the Jasper Ridge Biological Preserve near the university during that time.
He continued to sample these annually, flying between Australia and California, contributing to a valuable dataset that spanned nearly four decades.
In 2019, he handed the study to a former student Dr Lauren Hallett, who completed her Masters at UWA under Professor Hobbs’ supervision and is now a faculty member at the University of Oregon, and she continued the field observations.
“This research underscores the importance of long-term ecological studies and the critical role they play in understanding and mitigating the impacts of climate change,” Professor Hobbs said.
“The rapid response of these ecosystems to global warming serve as a fingerprint of the broader environmental shifts we are witnessing and UWA is proud to be involved in this global research, addressing some of the most pressing environmental challenges of our time.”