Epsilon Archive for Student Projects

Abstract

The High Arctic tundra is experiencing disproportionate warming compared to the global trend. This warming allows for carbon emissions to be released from organic soil at a higher rate: nevertheless, the warming conditions pose a higher risk in terms of permafrost thaw. Permafrost is any soil that remains frozen for a period of two or more years, trapping carbon and other nutrients in an inaccessible environment. Hence, permafrost acts as a carbon sink. When the permafrost region warms, it allows for this resource to become available for decomposition and release into the atmosphere. This study has been designed to further understand permafrost thaw in the High Arctic under conditions of grubbing disturbance, vegetation community composition shifts, and warming climates. Above-ground and below-ground interactions were investigated through a field study and compared to a 4-month incubation experiment measuring CO2 and CH4 fluxes in organic layer soil The field study found that wet moss tundra created a habitat with high plant productivity and high moisture content. Furthermore, areas with higher grubbing had a thinner organic layer depth, increasing the soil temperature and reducing the moisture level. Nutrient availability was highly dependent on the vegetation, but organic N was the most abundant form of N no matter the site. Through the incubation, it was discovered that CO2 was emitted at much higher levels than CH4. The permafrost inoculated with 10% organic soil had much higher levels of CH4 than organic soils. Furthermore, CH4 emissions changed based on the vegetation, with dry moss tundra emitting higher levels. Overall, this field of study still needs continued research, yet this study has helped to add to the search for an understanding of this environment in changing conditions.