Forests around the Earth are transforming at a shocking rate due to climate change, with trees advancing into previously barren tundra in the north while perishing from excessive heat farther south, scientists have found.
According to a recent study that analyzed the health of trees in North and South America, global heating, along with changes in soils, wind and available nutrients, is rapidly changing the composition of forests, making them far less resilient and prone to diseases.
Many areas of forest are now becoming more prone to vicious wildfires, causing the release of further greenhouse gases that heat the planet even more.
The study author Roman Dial and his colleagues have discovered that a patch of white spruce trees in north-west Alaska have “hopped” north into an area of Arctic tundra that hasn’t seen such trees in millenia. Their new research paper estimates the spruce are advancing north at a rate of around 4km a decade, aided by warming temperatures and changes to snow and wind patterns influenced by the shrinkage of sea ice in the region.
“The trees basically hopped over the mountains into the tundra. Going by climate models, this wasn’t supposed to happen for a hundred years or more. And yet it’s happening now,” said Dial.
The Arctic is heating up several times faster than the global average and the emergence of dark conifers on previously white tundra threatens to absorb more sunlight, causing further heating.
Farther south, separate research has found a change is under way at the boundary between the boreal and temperate forests, with species of spruce and fir increasingly unable to cope with the hotter conditions. Experts estimate that even small amounts of further heating, caused by human activity, could cause up to a 50% die-off of traditional boreal forest trees in certain places, with many other trees becoming stunted in their growth.