Treelines rising, moving North – in a warming world
Trees around the world are colonising new territories in response to higher temperatures. From the US west coast to northern Siberia and south-east Asia, trees are growing at higher elevations, and at higher latitudes as the climate warms…
The shift is revealed by the first global analysis of treelines published in the journal Ecology Letters.
However, the trees aren’t responding quite how scientists expected. Instead of advancing as summer temperatures rise, the trees’ ability to colonise new areas appears to be more dependent on whether winter temperatures warm…
Treelines tend to form wherever conditions for growth become too harsh. For example, at high altitudes and latitudes, the climate often becomes too cold for trees to survive. At this boundary, a treeline occurs, with forest on one side and shorter, hardier plants such as shrubs and plants on the other.
However, around the world, average air temperatures have risen during the past century. This warming has been most pronounced at high altitudes and latitudes, the exact places where treelines form. So in theory, trees should take advantage of these warmer, more hospitable climates, allowing treelines to advance higher and closer towards the poles…
Crucially, the trees do not seem to be responding to warmer summer temperatures. “We expected growing season warming to be the dominant driver,” says Melanie Harsch. “But we found that it was not, winter temperature was.”
RTFA. Been years since I spent a significant portion of my free time at or above treeline. But, I understand what this is all about.
You should, too.
