The wave of extinctions is not breaking everywhere the same. Tropical ecosystems seem to be hit harder by extinctions than expected given the number of species there. Furthermore, extinctions don’t always have the same impact.
Organisms play different roles in an ecosystem. If two animals share similar roles, it’s possible that when one goes extinct, the role might be taken over by the remaining species. However, there are other species that are absolutely essential to an ecosystem and their extinction can trigger a wave of other extinctions.
With ideas such as these in mind, researchers set out to understand how the ecosystems of the world would be impacted if the vertebrate species currently threatened with extinction died off.
A collaborative research team compiled characteristics of roughly 70 percent of all known vertebrates, some 50,000 species. They also looked at where on Earth these animals are found and how these environments would likely be impacted by extinctions.
The study, which was supported by the Estonian Research Council, showed that the impacts associated with losing different groups of vertebrates (mammals, birds, reptiles, amphibians and freshwater fishes) varied greatly depending on the region.
The Indo-Malay region would potentially lose 20 percent of its ecosystem function with the loss of its mammals and birds. Conversely, 30 percent of the palearctic realm’s ecosystem function would be lost with the extinction of its reptiles, amphibians and fishes.
“Our study will have important consequences in terms of conservation planning,” said study lead author Dr. Aurele Toussaint..”The Indo-Malay realm does not only host the highest proportion of threatened vertebrates on Earth but also threatened species with unique functional traits. Their loss would strongly imperil those fragile ecosystems. This highlights the need for action required for biodiversity conservation in Asia.”
Ecosystem function and the organisms that play roles in that greater whole are complex. This research is a step toward greater understanding and application of that knowledge on a global and regional scale.
“The conservation strategies should then go beyond the sole number of species and target the species with a unique ecological role which play a critical role in the ecosystem functioning,” said Dr. Toussaint.
“For example, there are around 300 amphibian species in the Palearctic realm compared to over 1,000 species in the tropical realms, but almost 30 percent of functional diversity would be lost in the Palearctic compared to 6 percent in the tropics. This shows that the threatened species in the Palearctic have much more unique functional traits.”
The study is published in the journal Nature Communications.