Landscape connectivity key to biodiversity: study

Genetic material must be allowed to move over vast distances, researchers say

University of B.C. researchers have mapped out how mammals are moving through human landscapes as part of a global effort to assess the biodiversity crisis.

The study, published in the journal Science on Thursday, looks at each country's connecting protected areas, which are created to give animals space to roam across vast landscapes. They concluded that connectivity is needed to prevent species loss in many areas of the world.

However they found Canada, which has the second-largest area of wilderness after Russia, is the third-most-connected country for mammal movement.

This is mainly because of Canada's North though, which still has vast areas of animal movement, according to the study's lead author, Angela Brennan, a conservation scientist at UBC and a fellow with the World Wildlife Fund.

“The vast majority of protected areas and the animals they contain are embedded in human landscapes. So, if animal movement is restricted between protected areas, that can result in blocking the flow of genes and blocking their access to important resources that they need,” said Brennan. “And that can exacerbate the biodiversity problems that we're having.”

In Canada, some of the species of mammals in need of connectivity conservation include elk, grizzly bears and caribou, according to the report.

Using data from the World Database on Protected Areas, the researchers created a protected area isolation metric, which measures the average animal isolation in national networks of protected areas. Each country was given a value that indicates a higher or lower degree of isolation on average.

Brennan said even though Canada rates well in terms of connectivity, there are still areas that have been identified as critical, such as the Yellowstone to Yukon corridor and the Coastal Mountain Range from B.C. to Washington state.

“These areas are critical for maintaining connectivity in North America,” said Brennan.

Some of the least connected countries for animal movement are Lebanon, Puerto Rico and Haiti, according to the study. Other countries that are in the top five per cent for having the most connecting protected areas include Greenland, Guyana, Egypt and Iceland.

Reducing the human footprint would help mammals move more freely between these areas, the report found. Solutions could include living fences, habitat stepping-stones and special overpasses.

“Having connected landscapes ensures that animals can move to access food, water and mates. And so, it ensures the flow of genes across landscapes, which is needed for healthy ecosystems,” said Brennan.

Researchers found that 50 out of the world's 846 ecoregions have the greatest potential to protect biodiversity, but many of these areas are also unprotected.

They also examined the proportion of critical connectivity areas that overlap with the Global Safety Net, a proposed global conservation scheme that identifies new priority areas for expanded protection. They found about 71 per cent of unprotected critical connectivity areas, including most of those suitable for future agricultural expansion, overlap with these Global Safety Net priority areas.