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Hello, my name is Michael Keating. I'm a master candidate in the Department of Biology. Wetlands
are the leading natural source of one of the world's most potent greenhouse gases - methane,
23 times more effective at trapping heat than carbon dioxide. Did you know that wetland
plants are hotspots of methane emissions to the atmosphere because they draw up methane
from the sediments and exhale it out of their stomata? They can do this because they have
airspaces in their roots and stems that allow for important gasses to be transported throughout
the plant. Now, very few people have tried to observe this plant effect in the entire
Mississippi River basin, but other researchers around the world have found that wetland plants
greatly increase methane emissions from wetlands. So, I set out to study methane fluxes from
2 wetlands in the Mississippi Delta region, speculating that wetlands in an agricultural
setting will have high methane emission rates because, let's face it, not all those fertilizers
stay on the farmland. A lot of it washes off as agricultural runoff into wetlands during
precipitation events. All these extra nutrients have the ability to stimulate the microbes
that are producing wetland, methane in the sediments. The goal of my study was to compare
methane emissions between vegetated and non-vegetated sites using clear, plastic chamber shown,
shown on my slide and so I collected gasses from vegetated and non-vegetated sites on
12 different days and across 4 different plant species and do you know what I found? On only
1 day of all 12 of those samplings did I find any difference in methane emissions between
vegetated and non-vegetated sites, meaning that wetland plants did not increase methane
emissions from these wetlands. An unexpected finding was significantly different methane
emissions between the 2 wetlands that I was studying, despite them being less than 400
meters apart from the each other. The fact that they existed in separate drainage systems
may contribute to the differences in methane emissions that I observed. The results of
my study have led me to believe that methane emission hotspots exist in the Mississippi
Delta and that they're influenced by factors other than plants. Just what controls methane
emissions from wetlands in the Mississippi Delta has the potential to influence management
decisions that will lead to improved air quality and global warming mitigation in the region.
Thank you.