Local plant diversity has been disrupted by climate change, research shows

Researchers at the University of York have discovered that climate change is disrupting local plant diversity. Increasing numbers of plant species are emerging across regions where the climate has experienced the most dramatic changes, particularly in colder areas.

In an era that is now officially known as The Anthropocene, human activities have driven substantial declines in biodiversity on a global scale. However, even though the total number of plant species worldwide is in a state of decline, local plant diversity appears to be increasing in some places. 

According to the researchers, rapid changes in rainfall and other climate factors may be allowing new species to thrive. 

“We used a large dataset of over 200 studies in which botanists had counted the number of plant species present in survey plots situated all around the world,” explained study lead author Dr. Andrew Suggitt.

“We tested for the influence of climate change alongside other well-known drivers of diversity change, finding that the local differences in climate, and exposure to climate change, were responsible for a substantial part of the change in plant species numbers found in these surveys.”

“Our models suggest that typical rates of climate change in cooler regions of the world are driving an increase in local species richness of 5% per decade.”

Dr. Suggitt explained that this number is really quite significant if the phenomenon continues for 13 decades or more, especially considering that humans have already been changing the climate for over half a century. He also pointed out that climate change is expected to persist until the end of the century, and possibly beyond. 

“This does not mean that the botanical world gets a clean bill of health. We are living in ‘The Anthropocene’ epoch, and some plant species have become globally extinct. Many, many more are endangered,” said study co-author Professor Chris Thomas.

“However, there is a disconnect between what is happening at that global level and the average change to plant diversity that can be observed in, say, a one meter square plot of ground.”

“The effect of climate change may not be as dramatic as a meadow being turned into a car park, or a forest being cut down, but it’s a pervasive effect that is already evident over vast areas of the Earth’s land surface. For example, warmth-loving bee orchids have started arriving at a much wider variety of sites across the north of England, taking advantage of the changing climate.”

“The data we have analyzed tells us that colonists are tending to arrive faster than incumbents disappear, giving rise to slight increases in plant diversity in places where the climate is changing the most.”

“The recent global assessment report by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services* highlighted worrying declines in plants and animals around the world,” added Dr. Suggitt.

“But it also highlighted the sore need for greater clarity over how climate change is shuffling the deck of plant species found in particular locations – especially in under-sampled areas such as the tropics, Africa and Asia.”

“We hope our study opens the door to a fuller understanding of how climate change is affecting plant communities, and what this means for the conservation of nature and its contribution to people.”

The study is published in the journal Current Biology.

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By Chrissy Sexton, Earth.com Staff Writer

Paid for by Earth.com

Image Credit: Prof Chris Thomas, University of York