Changing weather patterns are causing Arctic soil to lose carbon at a rapid pace, leading to an outcome that further reinforces global temperature increases and climate change. Research can be found in the scientific journal Climate Change Responses.
For what seems like an eternity, shrubs, grasses and other plant species have taken carbon out of the Arctic atmosphere and held it in storage underground, where various microbial organisms use the stored organic material as food.
At the moment however, the landscape is being transformed as the growth of vegetation accelerates rapidly, yet the changes related to carbon storage in Arctic soil are inadequately understood. Soil in the arctic holds roughly 50% of global carbon held underground, which is more than double the carbon in the earth’s atmosphere.
The decomposition of carbon in soil is particularly sensitive to changes in temperature, and it represents a huge potential source of greenhouse gases. As such, decomposition could quicken the pace of global climate change, turning the Arctic from a carbon catcher to a carbon producer.
Determined to discover the dynamics involved in soil decomposition, Dartmouth researchers traveled to western Greenland, where they collected plant soil samples to analyze back in the lab. They conducted a series of controlled experiments that looked at the carbon-dioxide emissions from two soil-vegetation types incubating at five different temperatures and two moisture levels.
The researchers concluded that soil from grassy-areas could store more carbon, but would lose it more quickly to decomposition, and had a higher temperature sensitivity than soil from shrub-areas. What all this suggests is that soil decomposition in grassy areas of the Arctic is going to increase rapidly as the temperature gets higher and moisture levels rise, all resulting in increases in carbon-dioxide emissions.
Shrub vegetation is expanding across the Arctic and this process deserves the attention of researchers. The study adds to the poorly-understood relationship between soil decomposition and a range of variables such as vegetation type, temperature and moisture level, giving a clearer picture of how global climate change impacts a carbon-rich area like the Arctic.