When glaciers disappear, the bugs move in
We've all been stunned by images showing the dramatic retreat of mountain glaciers. Yet few of us have given much thought to what happens next.
Now the first study to look at how life invades soil immediately after mountain glaciers melt has an answer. Primitive bacteria step in to colonise the area, enrich the soil with nutrients, and even cement the ground, preventing landslides, say researchers who have studied the process in the Peruvian Andes.
A few studies have looked at the types of plants that colonise mountain valleys that were previously covered in ice. But before plants move in there is usually a period, which at high latitudes and altitudes can last several years, during which the newly uncovered soil appears totally barren (see picture, right).