Arctic Bone Nurseries

Life and death are two sides of the same coin. In death, an organisms body is broken down into its constituent parts and redistributed throughout the environment. As such, decomposition is a major player in the global cycling of nutrients. Nowhere does this become more apparent than in nutrient limited habitats like the Arctic Tundra.

The Arctic is known for being quite harsh. A combination of low temperatures, low water availability, and short summers make for tough conditions for any plant. What's more, low temperatures and water availability also mean nutrients are hard to get at. It stands to reason then that any potential uptick in nutrient availability would be a boon for Arctic plant life.

This is where dead animals come in. When a large animal like a muskox dies, its body can take many years to break down. Each summer, as temperatures rise above freezing, decomposition slowly eats away at the tissues. Research has found that nutrient levels, specifically nitrogen, are much higher within a meter radius around the carcass. Plants in this region were found to have higher nitrogen levels in their tissues and achieved the most luscious growth.

Nutrients aren't the only benefit carcasses provide, they also offer a favorable microclimate. Many herbivores instinctually avoid feeding around dead animals as a way of limiting exposure to disease. Researchers found that grazing levels were lower around most of the carcasses they studied. Another benefit is shelter. Wind is an ever present force to reckon with on the tundra. Carcasses provide a sheltered area that serves as an oasis for seeds to germinate and grow. The carcass also acts like a filter, collecting debris and allowing soils to build over time. Other animals may find this a favorable place to hide or hunt and thus the importance of these carcass islands becomes all the more apparent.

Photo Credits: Neil Shubin and Brian Whitlock

Further Reading:
http://pubs.aina.ucalgary.ca/arctic/arctic55-4-389.pdf