Examining Relationships Between Methane Emissions and Aquatic Vegetation in Arctic Lakes Using Remote Sensing Techniques and Field Measurements

• Main Author: Sears, Helen B.
• Format: Text
• Language: unknown
• Published: University of New Hampshire Scholars' Repository 2024
• Subjects: Northern Sweden; permafrost
• Online Access: https://scholars.unh.edu/thesis/1847; https://scholars.unh.edu/context/thesis/article/2888/viewcontent/Sears_unh_0141N_11757.pdf

Lake ecosystems are significant contributors to atmospheric methane (CH4) budget. Aquatic vegetation provides inputs to lake sediments of carbon that then influence the production and emission rates of CH4 from those sediments. Understanding the spatial variability and seasonal changes in the distribution of aquatic plants and CH4 emissions can help identify potential feedback with climate warming. Stordalen Mire, located in the discontinuous permafrost zone in Northern Sweden, is an ideal area to study the relationship of vegetation cover to CH4 emissions from lakes in the Mire, because there are extensive datasets relating to both these parameters for this location. Still, there is a gap in our understanding about the coverage and amount of aquatic submerged and emergent vegetation in these lakes, how the vegetation changes seasonally, and its potential for influencing CH4 production and emission rates. Using lake imagery from an Unpiloted Aerial System (UAS) that was collected multiple times during vegetation growing months (June-July) in 2023 we were able to monitor seasonal changes in vegetation percent cover and abundance in these lakes. The UAS imagery allowed the tracking of changes in the vegetation throughout the season. Seasonal vegetation change and CH4 ebullitive emissions showed a negative correlation over the sampling season at certain sites, however, there are a variety of factors that are at play. Looking at these variables in future research, as well as expanding to include plant mediated flux with the CH4 ebullitive emissions, could give some more insight into these gaps in our findings.