Peatlands, or wetlands where plant matter is accumulating, are an indispensable part of Earth's carbon cycle. While these environments only cover 3% of Earth's continents, they contain twice as much carbon as is in the biosphere and about the same amount of carbon currently in the atmosphere. Further, this carbon is removed from the atmosphere and locked away for millennia. Many factors, including vegetation type, hydrology, and permafrost affect the rate at which peatlands remove carbon from the atmosphere. My work seeks to understand how changing climate will impact the factors controlling the carbon cycle of peatlands. Will anthropogenic warming increase growth rates--a negative feedback on warming--or will warming cause peatlands to decay faster--a positive feedback?
The southern hemisphere westerly winds are another important part of Earth's carbon cycle. Their strength and position determine the rate at which carbon dioxide is stored or released from the Southern Ocean--the part of the ocean that surrounds Antarctica. My work seeks to understand how changing climate will feed back on the strength and position of the Southern Westerlies. To accomplish this, I use multiple chemical and paleontological methods in the peatlands of New Zealand and Chile to reconstruct past changes in westerlies-related climate. Understanding how abrupt climate changes have impacted the westerlies in the past will allow us to create more detailed and accurate predictions of future changes.
Coastal marshes are extremely important habitats. These wetlands keep our waterways clean, provide nurseries for myriad fishery species, and protect the built environment from damage by storms. The sediments of coastal marshes have recorded centuries of human activity in the New York area--human activities that place the health of these marshes at risk. Contamination by heavy metals, wastewater, pharmaceuticals, and other pollutants is well documented, however, the most urgent problem facing marshes today is accelerating sea level rise due to anthropogenic warming of the climate. So far, some of the marshes have been able to grow to keep up with the increased rate, but for how long? Many marshes are already beginning to drown. Our work seeks to understand how fast marshes can accrete to keep up with sea level and what we can do to help protect our marshes from being washed away.