Some 1,500 scientists urged Canada to protect its vast Boreal Forest from mining, forestry and energy operations, to stem global warming and destruction of wildlife habitats.
The scientists from around the world asked that half of the forest, which spans 1.4 billion acres (567 million hectares) in northern Canada, be preserved.
The remaining half would require "carefully managed development," they said in an open letter to Canadian leaders.
The Boreal Forest is "the largest intact forest and wetland ecosystems remaining on earth," home to the planet's largest populations of wolves, bears, and caribou, many fish, as well as three billion migratory birds.
It is also the single largest terrestrial carbon storehouse in the world, capturing 186 billion tonnes of carbon dioxide (CO2), the scientists said. CO2 is one of the main "greenhouse" gases blamed for global warming.
However, the forest is under "increasing pressure" from logging, mining and oil and gas exploration and only 10 percent of the huge area has been protected, they lamented.
"We are losing so many of the world's great forests, despite the best efforts of conservationists," said David Schindler, an ecologist at the University of Alberta.
"Canada's Boreal Forest offers what may be our last, best chance to do things right, but only if our leaders act decisively and act now."
At a press conference in Ottawa, the scientists said the Boreal Forest has been "an important resource for Canada" over the past century, accounting for 37.8 billion Canadian dollars (34.2 billion US) in annual economic activity.
Ten percent of the forest has already been touched by mining or oil and gas operations, and another 20 percent has been clear-cut by forestry firms, mostly along its southern tip where biodiversity is richest, they said.
If governments wait 20-25 years to protect the Boreal Forest, it will be too late, said Jeremy Kerr, an ecologist at the University of Ottawa.
Forest renewal -- planting trees to replace cut timber -- takes more than 100 years to take root, he added, and displaced wildlife often do not return when their habitat is disturbed.
About 98 percent of the forest is government-owned and leased to companies for mining, forestry and energy exploitation.

(From  Taiwan News)