I also wonder how many trees there are in the arctic?
southern edge has alders, birch, willow, spruce and firs (for shrubs there’s bearberry and some members of the rose family). As the arctic warms, these species will also migrate north.
Consider Greenland; 400K years ago at least the southern 1/3 was covered in forests and quite livable:
“Greenland’s temperature once varied from 50 degrees Fahrenheit in summer to 1.4 degrees Fahrenheit in winter—the temperature range that the tree species prefer.”
https://www.livescience.com/7331-ancient-greenland-green.html
Very few.
I’ve seen things growing in low draws near water crossings that would pass for the start of a tree.
Over the course of 5 summers it has not increased in size, not width nor height. I think it has reached its maximum size for the climate..
.I have been tempted to put a tree spike fertilizer in the ground and see if that would have any effect