Morris Katz Memorial Lecture in Environmental Research: Warwick Vincent
May 28, 2012, 2:30pm-4:30pm
Microbiologist Warwick Vincent, of Université Laval's Aquatic Ecosystem Studies Laboratory, will talk about research in the Canadian Arctic that suggests global climate change has begun to induce abrupt, discontinuous shifts in high latitude ecosystems structure and function, and that Canada’s Arctic frontier is moving into a new dynamic state that we urgently need to better understand.
The Canadian Arctic contains a spectacular variety of aquatic ecosystem types including vast networks of lakes in glaciated basins, permafrost thaw lakes, large rivers discharging to the Arctic Ocean, ice shelves, lagoons and other coastal ecosystems, and perennially ice-capped, solar heated lakes. The lab's analyses of the molecular microbiology of these waters have revealed diverse communities in each of the three domains of microbial life, with implications for biogeography, food web structure and biogeochemical processes including greenhouse gas fluxes.
The Arctic is currently warming at more than twice the global average, and some of these aquatic ecosystems have begun to experience step-like changes in their physical and ecological regimes. Over the last 10 years, several types of ice-dependent ecosystems at the lab's study sites in the High Arctic have experienced abrupt changes, resulting in complete habitat loss at some locations. To obtain a longer term perspective, the lab analyzed coastal sediment cores taken behind the Ward Hunt Ice Shelf. The results indicate large variability in past ice conditions, however the synchronicity of its current break-up with the collapse of ice shelves in the Antarctic Peninsula region is without precedent over the last 8,000 years, implying that we have entered a new phase of pole-to-pole deglaciation.
|Location:||Senate Chamber, N940 Ross Building|
|Sponsor:||York Centre for Atmospheric Chemistry|
|Posted by:||Carol Weldon|