Less Biodiversity Decreases Climate Change Resilience
A new study has found that the impact of climate change is likely to be worse if species are lost. High biodiversity increases the likelihood that some species will be sufficiently resilient to a changing environment.
In order to discover how biodiversity affects climate change resilience, biologists at the University of Gothenburg in Sweden experimented with eelgrass meadows in shallow inlets on the west coast of Sweden reveal that climate change can exacerbate the negative effects of losing sensitive species, and that the insurance effect of biodiversity may be weaker than what we typically assume.
This is thought to be due, in part, to eutrophication - the response of an ecosystem to the addition of artificial or natural substances. When eutrophication occurs it favors mats of filamentous 'nuisance' algae which shade and suffocate the eelgrass. The loss of cod in the area, in part has also resulted in a huge increase in numbers of smaller predatory fish.
At the Sven Lovén Centre for Marine Sciences' Kristineberg Marine Research Station on Gullmarsfjorden, researchers from the University of Gothenburg's Department of Biology and Environmental Sciences have developed miniature ecosystems in outdoor aquariums and have been investigating how future ocean warming and ocean acidification could affect the balance between eelgrass and filamentous algae. The effects were unexpectedly clear and unambiguous: it was the diversity of algal herbivores that determined the extent to which the ecosystem was affected by warming and acidification.
The researchers believe that we should be concerned about the results. "Most management is based on the assumption that we [can] afford to lose the most sensitive species because other, more resilient species will take their place," says researcher and biologist Johan Eklöf. "But this may not be the case with future climate changes, as it can reduce the net efficiency of the resilient species - without directly affecting them."
However, the researchers are also careful to point out that there is still hope if society does decide to take action. "If we protect the local biodiversity we still have, and restore the diversity we've lost, by for example protecting predatory fish stocks in coastal areas and reducing nutrient loading, then we'll probably be able to increase the ecosystems' resilience to climate change."