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Written by: Bianca Marcellino

The Tundra biome is characterized by extreme cold weather, low biotic diversity and precipitation levels, short growing seasons, low-growing vegetation of simple structure, and nutrients available mostly in the form of dead organic matter. Only a small portion of the permafrost thaws each growing season, called the active layer, which limits the vegetation to low shrubs, sedges, flowering plants, and mosses, all with shallow roots and short reproductive cycles. 

In recent decades, the Tundra has rapidly warmed causing a variety of environmental effects including: melting sea ice resulting in increased water levels, shifting vegetation ranges, and release of CO2 stored in the permafrost. Presently, northern Tundra soils hold ~30% of the total soil organic carbon, which with the continued increase in temperature expected to occur over the next decades, threatening the release of this carbon sink; has alarmed the scientific community and gained the name the “Carbon Bomb”.

The warming temperatures may promote the expansion of the Canadian population into previously sparse areas such as the Tundra, fostered by the increased ability of the Tundra to support a greater abundance of vegetation (Deslippe 2011). This activity serves to counteract the lurking prospect of the carbon bomb ‘explosion’; however, the warming temperatures are also expected to drive native Arctic species further North if they are unable to adapt to the warming climate of their original regions. It is unclear whether the release of atmospheric carbon through the thawing of the permafrost will result in the Tundra becoming a carbon source via heightened microbial activity, or remain a carbon sink through increased vegetation growth.

The question arises - is it possible to plant native Arctic plants, which are well adapted to the current Tundra climate, as a mitigation strategy to help combat the “Carbon Bomb”? This could act to support Artic herbivores and their subsequent food webs, and potentially help to limit their displacement to more Northern areas, but may be impractical given the scale of the Canadian arctic and the limitations in our knowledge of how arctic ecosystems are being impacted by climate change.

This uncertainty clearly identifies the need for further study of Canada’s arctic in order to find the best tools to combat the carbon bomb.

Additonal Reading

National Geographic - Tundra Threats Explained

The Narwhal - Arctic tundra is 80 per cent permafrost. What happens when it thaws?

Sciencing - Plant Adaptations in the Tundra 

References

Deslippe, J. R., M. Hartmann, W. W. Mohn and S. W. Simard. 2011.  Long-term experimental manipulation of climate alters the ectomycorrhizal community of Betula nana in Arctic tundra. Global Change Biology. 17:1625-1636.

Gilg, O., K. M. Kovacs, J. Aars, J. Fort, G. Gauthier, D. Grémillet, R. A. Ims, H. Meltofte, J. Moreau, E. Post, N. M. Schmidt, G. Yannic and L. Bollache. 2012. Climate change and the ecology and evolution of Arctic vertebrates. The Year in Ecology and Conservation Biology 1249:166-190.

Steiglitz, M., A. Giblin, J. Hobbie, M. Williams and G. Kling. 2000. Stimulating the effects of climate change variability on carbon dynamics in Arctic tundra. Global Biochemical Cycles 14:1123-1136.

Treat, C. C. and S. Frolking. 2013. A permafrost carbon bomb? Nature Climate Change 3:865-867.

UC Berkeley Biomes Group, S. Pullen and K. Ballard. 2004. The Tundra Biome. Berkeley University of California.  Berkeley, CA, USA.