It may be related to a combination of factors, such as melting snow and dissolved nutrients, light intensity, and possibly the length of daylight. The plant debris, along with dead snow algae and small insect life, is broken down by decay bacteria and fungi, thus making the essential nutrients available to the algae. The powerful mountain winds that bring nutrients to the snowbank may also serve to disperse the dormant cells to distant snow-capped mountains. There are reports of snow worm populations literally covering snow fields and glaciers of Alaska and British Columbia. Their tiny dark gray or black bodies absorb solar radiation and heat.
T here are many other striking examples of colorful microscopic algae in our environment.
Algal cells color the trunks of trees velvety green, and the trunks of Monterey cypress on the Monterey Peninsula of California a brilliant orange. The colorful crusted growth on rocks and boulders is caused by an intimate association between algae and fungi called lichen. In the Sierra Nevada and high desert ranges to the east there are many colors of lichen, including black, orange, green, yellow and chartreuse. The unicellular alga Dunaliella , related to snow algae, and salt-loving bacteria grow in salt lakes and brine pools throughout arid regions of the world and often color the water vermilion red. Pink Salt Lakes See Article About Desert Varnish And Lichen Crust C ells of microscopic algae are able to survive in a variety of unusual places, from the dry salt crust and brine pools of blistering desert playas to boiling hot springs and windswept lichen-covered peaks of high mountains.