How do northward-moving trees reduce the area of Arctic tundra?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Rolling tundra in Alaska with red, yellow, and green fall foliage, set against rugged mountains with patches of grass and exposed rock. — Tundra Alaskan mountain and tundra vegetation in the fall.

As global warming causes temperatures to rise, Arctic and alpine tundra ecosystems are increasingly being invaded by tree species migrating northward from the forest belt. This migration directly reduces the geographic extent of the Arctic tundra.1

The expansion of these trees further accelerates the loss of tundra through a feedback mechanism: the darker surfaces of coniferous trees absorb more solar radiation than the lighter-colored snow and ice they replace. This reduction in albedo (surface reflectance) causes the surface to absorb more heat, which increases the rate of warming in the region and facilitates further encroachment of trees into previously treeless areas.1