Faster Extinctions

This handout photo, taken Dec. 2012, in Brazil, provided by Stuart Pimm, Duke University, shows a baby golden lion tamarin. Once thought to be extinct, this tamarin is a success story because biologists have helped set aside land for them. (Stuart Pimm, Duke University/Associated Press)

As forests are cut into smaller pieces by roads, agriculture and other human activities, 85 per cent of animals that live in the woods are disturbed. But that disturbance is not equal. Some species do better than others.

New research has shown that half of the world's forest habitat is now within half a kilometre of a forest edge that meets a road, a clear-cut, a farm or a town. Scientists looked at 1,673 species of mammals, birds, reptiles and amphibians living in forests that have been fragmented and found that there were winners and losers when it came to the disturbance.

When trees are cleared to make even a narrow path for a road, a new environment is created in that open space, with more sunlight, and hotter, drier conditions than that of the forest deep. Animals that like forest edges, such as snakes, benefit from the disturbance, while the more reclusive types who prefer the deep, dark interior find their habitat has become smaller.

This is not exactly a good news/bad news story, because creating a new environment can bring in invasive species that can cause further disturbance.

The obvious solution is to cut down on cutting down in the forests, which will not be easy because logging and oil companies see resources there, while cities and towns continue to grow. Along with that, more agricultural land is needed to feed our growing population.

Preserve half the world's biosphere

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Aerial view of deforestation in the Western Amazon region of Brazil in September. If all ecoregions could be brought up to at least half protected, it would allow species on the brink of extinction to recover. (Carl De Souza/AFP/Getty)

But according to the American Institute of Biological Sciences, we should take matters one step further. They are suggesting the only way to prevent the mass extinction caused by human activity that is currently underway, (the extinction rate of species around the world today has not been seen since an asteroid struck the Earth 66 million years ago) is to preserve half — that's right, half — of the world's biosphere.  

They used a map, Realm of the Earth's 846 ecoregions, such as tropical rainforests, boreal forests, grasslands, even deserts. They found:

  • Only 12 per cent exceed half protected.
  • 37 per cent fall short of half but could recover.
  • 24 per cent are in peril.

If all ecoregions could be brought up to at least half protected, it would allow species on the brink of extinction to recover, and in the long run, provide more resources for humanity. Natural areas are the breeding grounds for biodiversity.

Benefits both urban and wild areas 

In order for this to work, these protected areas have to be large, which will be difficult because humans are everywhere. One solution is to create natural corridors that link existing parks together, such as the Yellowstone to Yukon Project. This is an international effort to connect the Rocky Mountains from Yellowstone Park in Wyoming, through the mountains of Alberta, British Columbia, The Yukon and Northwest Territories, right up to the Alaskan border. The continuous swath of green, which already includes large parks such as Glacier, Banff, Jasper and Yoho, provides a wildlife corridor for animals that migrate north south, as well as a wide range of habitats and biodiversity.

Preserving large tracts of land does not mean keeping humans out. On the contrary, it is a matter of managing both wild and urban areas so both will benefit. Preserved lands cultivate more animals for hunters and anglers, not to mention the benefits to young and old alike of visiting purely natural areas. Young people are becoming "nature deprived" by spending more and more time indoors playing with electronics rather than playing outside.

Bison relocation

Bison have been absent from Banff National Park for more than a century. Wildlife corridors offer help to animals that migrate north south, as well as a wide range of habitats and biodiversity. (Johane Janelle/Parks Canada)

The benefits of marine protected areas, which the scientists say should also be expanded, lie in their ability to cultivate more fish. When populations reach a certain point, fish leave the protected areas and move into surrounding waters where they become the supply for the fishing area. In other words, by having no fishing zones, we end up with more fish to catch.

Canada is in a good position to meet the half preservation goal because our country is so large with huge regions, such as the boreal forest, that stretch right across the country, still relatively untouched.

When you look at the Earth as a whole, there isn't a lot of land. Most of the planet is covered in water. Much of what sticks above the surface is desert, or frozen. That leaves only one quarter of the Earth's surface green

That alone makes it worth protecting.