- Wilderness areas buffer species against the risk of extinction, reducing it by more than half, a new study shows.
- Places with lots of unique species and wilderness with the last remaining sections of good habitat for certain species had a more pronounced impact on extinction risk.
- The authors contend that safeguarding the last wild places should be a conservation priority alongside the protection and restoration of heavily impacted “hotspots.”
Plant and animal species living in wilderness areas are less likely to go extinct, a recent study has found.
Defined as intact habitats that haven’t been affected by human use on industrial scales, wilderness “buffers” the life it supports against the threat of extinction. In fact, it slashes the risk on average by more than half compared to that faced by species living outside these areas, Moreno Di Marco, James Watson, and colleagues reported Sept. 18 in the journal Nature.
“This research provides the evidence for how essential it is for the global conservation community specifically target protecting Earth’s remaining wilderness,” Watson, an ecologist with the University of Queensland, in Australia, and the Wildlife Conservation Society, said in a statement.
In an earlier study, Watson and a team of researchers reported that 3.3 million square kilometers (1.27 million square miles) of wilderness — an area the size of India — has been lost since the 1990s. At the same time, a recent report from the United Nations’ Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services found that 1 million species are staring at the prospect of extinction.
Currently, however, the focus of a lot of conservation is to protect heavily impacted “hotspots” that are disappearing as a result of human use and where many of the species are sliding toward extinction, Di Marco, the study’s lead author, said in an interview.
“That’s OK if your objective is to prevent the extinction of species that are highly threatened,” said Di Marco, an ecologist at CSIRO Land and Water (Australia’s national science research agency) and Italy’s Sapienza University of Rome. But that approach doesn’t account for the benefits that intact wilderness areas provide for biodiversity, he added. Until now, no one had tabulated the role that wilderness plays in the survival of species.
Watson and several colleagues published a map of what’s left of Earth’s wilderness in 2017, and a 2016 map plots out the locations and severity of human pressure around the globe. The team drew from that data and used a new biodiversity modeling tool developed at CSIRO Australia, which combines the differences in the makeup of species at different sites with the habitat quality at those sites. They were then able to calculate the relative importance of wilderness compared to other habitats in preventing species extinction. They found that species living outside wilderness areas were more than twice as likely on average to be threatened with extinction.
Wilderness landscapes span the globe, from the high Arctic to equatorial rainforests. It turns out that the “buffering effect” of wilderness on extinction risk holds across a wide range of these habitats.
“There wasn’t just one ecological or biogeographic region where wilderness areas were important,” Di Marco said.
The authors note that all wilderness areas have “intrinsic conservation value,” and they store carbon, provide clean water and support the livelihoods of indigenous communities around the globe.
“Wilderness areas are known to play fundamental roles for humanity,” Di Marco said.
In some places, though, the effect was more substantial, especially where large tracts of wilderness still persist. Spots with lots of unique species also had a more pronounced impact on extinction risk, as did places that hold some of the last, best slices of good habitat for certain species.
But when the scientists incorporated a map of global protected areas, they found that these high-priority wilderness areas, which they identified on every continent, were only about as likely to be designated as parks and reserves as wilderness areas that weren’t as vital in warding off the risk of extinction.
The central concern for the global conservation agenda right now is the protection and restoration of the most threatened habitats and species. While that’s critical to stemming the unsettling rate of biodiversity loss, it’s only part of the solution, Di Marco said. He and his colleagues contend that it’s equally important to safeguard the last wild spaces.
“If we do lose those areas, what’s going to happen is a very high increase potentially in extinction rates,” Di Marco said. “We cannot disregard them.”