New research led by scientists in Trinity College Dublin and Hokkaido University has shown that predator species may tackle the negative impacts of climate change by mitigating against the loss of biodiversity.
The team of scientists who are behind the discovery say their findings underline the importance of conserving biodiversity and top predators. They also highlight the potential for species extinctions to worsen the effects of climate change on ecosystems.
The scientists assembled communities of freshwater organisms in experimental streams at the Tomakomai Experimental Forest in Northern Japan.
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The stream communities were exposed to realistic heatwaves and some included a dominant predator (a sculpin fish), while others did not.
The scientists also found that heatwaves destabilized algal (plant) communities in the streams such that the differences normally found among them disappeared and they resembled each other much more closely—equating to a loss of biodiversity—but this only happened when the predator was absent from the community.
Algal communities are known to be important in streams because they form the energy base for all other organisms, so loss of algal biodiversity can propagate to impact the entire ecosystem.
The scientists also discovered that important heatwave effects—such as shifts in total algal biomass—only emerged after the heatwave had passed, underlining that even catastrophic impacts may not be immediately obvious.
Dr Samuel Ross, who led the experiment in Japan as part of his PhD research in Trinity’s Department of Zoology, said they found that predator extinctions can interact with heatwaves to further undermine the stability of ecosystems.
