Ecologists have long believed that, as climate change picks up speed, so would changes in nature. Rising temperatures and shifting climatic zones would push species to move into new habitats at an ever-increasing pace, dramatically changing ecological communities.
However, new research from Queen Mary University of London (QMUL) has found the opposite is true. Analysing a massive database of biodiversity surveys, including marine, freshwater and terrestrial ecosystems over the last century, scientists revealed that species’ turnover has significantly slowed.
“Nature functions like a self-repairing engine, constantly swapping out old parts for new ones,” Dr Emmanuel Nwankwo, lead author of the study, explained to Queen Mary News. “But we found this engine is now grinding to a halt.”
Researchers compared species turnover rates – the speed at which species composition changes – before and after the 1970s, a turning point marked by acceleration in global surface temperatures and environmental shifts. The data revealed that, rather than accelerating as climate change picked up, the turnover rates slowed down considerably.
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“We were surprised how strong the effect is. Turnover rates typically declined by one third,” Professor Axel Rossberg, co-author of the study, told Queen Mary News. The slowdown proved consistent across different environments, affecting everything from terrestrial bird communities to the seabed.
To understand why, the researchers looked at how ecosystems are organised. Their findings suggest that, rather than simply reacting passively to external climate factors, ecosystems appear to operate in a state known as the “multiple attractors” phase.
This posits that species change continuously due to internal factors, even without environmental changes, akin to a giant, never-ending game of rock-paper-scissors. The QMUL study provides strong empirical evidence that the phase, first predicted by theoretical physicist Guy Bunin in 2017, does exist and in fact dominates nature.
