Glacial Feature of the Month: Glacier Moss

Matanuska Mice

Nobody really knows what they are in for when first coming to the Matanuska Glacier. Some expect an arctic wasteland of snow and wind while others expect arching ice caves reaching up to the parking lot. One thing that nobody expects to find are balls of moss rolling around on the ice like boreal tumbleweed.

When scientists with a sense of humor discovered these on the Matanuska, they decided to name these moss balls “glacier mice” and the name is as fitting as it is comic. These moss balls are completely round, fuzzy, free floating, and often travel in ‘herds’ around the glacier. The have been known to exist since the 1950s, yet science still knows very little about them. 

Moss Movements

A ‘herd’ of glacier moss roam over the Matanuska Glacier

I have been fascinated by moss ever since a life-changing Ecology class freshman year of college. In lab we would go out into the woods and study the moss as the frost slowly melted away. A friend and I “borrowed” a magnifying glass from the lab and would explore on Friday afternoons in the rainy spring woods of Vermont. Now as a guide at MICA I have the opportunity to educate people about these crazy little critters.

Mosses are some of the oldest groups of plants on earth. They don’t have complex root systems like trees and other typical plants. While this stops them from reaching the incredible height or size of other more “advanced” plants. This simplicity allows moss to grow in some places that no other plants could dream of.  Anywhere where there is enough water and a surface to grow on, you can be sure to find mosses thriving unassumingly in the background. 

Embracing the Changes

While other plants need stable ground to be able to survive, glacier mice have managed to embrace the flow and change of the glacier. They start as just a few tiny green fibers surrounding a pebble or dust grain and grow outward. This allows the old dead moss to act as a sort of soil for the new moss to expand on. Though they usually reach only 1-2 inches in diameter before being broken up into smaller pieces by tumbling rock and ice, I’ve found moss balls nearly a foot and a half in diameter!

A microscopic image of a water bear, also known as a tardigrade

The moist dirt on the inside of a glacier mouse is a rare haven for other life. This makes a single ball far more than just one plant alone in an icy wilderness. Glacier mice are an entire ecosystem, a vehicle for life that all exists inside one rolling ball.  While many different species of moss can coexist on the outside, dozens of species of tiny invertebrates like water bears (the coolest bug you’ve never heard of!) and worms live within the moss ball. All of these plants and animals are content to follow the natural change of the glacier.

As humans we get locked into our habits and expectations. We thrive on consistency and when life, or glaciers, change, we easily get frustrated and wish things were back to how they were.  Glacier mice take change with more grace; they roll with the changing ice. They use this untamable force to move on to new places and expose themselves to the Alaskan sunshine. Maybe these simple balls of moss can teach us a thing or two about embracing change.

By Adam