Date(s) - Wednesday, March 18, 2020
12:10 pm - 2:00 pm
Room SS2102, Sidney Smith Building, 100 St. George Street
100 St. George Street
Sarah Finkelstein, Associate Professor, Department of Earth Sciences, University of Toronto
Abstract: Many types of wetlands act as long-term carbon sinks, taking up carbon from the atmosphere and storing it in the form of poorly decomposed plant material in waterlogged soils. As a result, peatlands located in the boreal and sub-arctic regions, for example, store more than 450 gigatonnes of carbon (this is the low end of recent estimates), which is perhaps one third of the total global soil carbon pool, despite the fact that they cover less than 3% of the Earth’s land area. In addition to being major carbon sinks where large carbon pools have accumulated, global wetlands are the largest natural source of methane to the atmosphere. Thus, wetlands are major players in the global carbon cycle and can have either a net positive or net negative impact on the climate, depending on environmental conditions as well as the land use decisions we make. Ontario is particularly significant in terms of wetlands as the Hudson and James Bay Lowlands in Northern Ontario are one of the largest contiguous peatlands in the world, and Southern Ontario, formerly a wetland-rich landscape, has lost more than half of all wetland area due to drainage for cropland or urbanization. Some efforts are underway now towards restoration of some of those wetlands and land-use decision making related to wetlands is actively ongoing in both southern and northern Ontario. In this talk, I will present results from our research on how carbon pools accumulate in wetlands, and how climate affects the ability of wetlands to be long-term climate sinks. These results have been developed through paleoecological analyses of wetland sediment cores our team has collected from many locations in Ontario. These cores extend several thousand years into the past and provide a diverse suite of geochemical and biological tracers to reconstruct past changes. I will also discuss the extent of wetland losses in Southern Ontario over the last 150 years, and emphasize the importance of land-use decision making for preserving the capacity of these remarkable ecosystems to contribute to carbon sequestration.
Brief Bio: Sarah Finkelstein is a geoscientist with interdisciplinary training in ecology, geography and the earth sciences. She is an Associate Professor in Earth Sciences at UofT with research interests in paleoclimate and paleoecology, wetlands, impacts of recent climate warming on freshwater ecosystems, and the capacity of wetlands to mitigate climate change. Using the principle that “the past is the key to the present, and to the future” Sarah’s research focuses on developing reconstructions of past changes in Earth’s environments and using those results to better understand contemporary processes and future outcomes. She is involved in partnerships with government scientists, and NGOs including the Nature Conservancy and Ducks Unlimited, to contribute to evidence-based policy decision-making, and she serves as an associate editor of the journal Wetlands.