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Our Next Speaker

560th Meeting

10 December 2023

ANNUAL GENERAL MEETING

1. Minutes of the 2022 Annual General Meeting.
2. Report of the Treasurer.
3. Report of the Nominating Committee and Election of Officers.
4. Other business.
5. Adjournment.
_______________

Jennifer Baltzer

FROM RESILIENCE TO REGENERATION FAILURE: IS BLACK SPRUCE AT A TIPPING POINT IN BOREAL NORTH AMERICA?

Intensifying wildfire activity and climate change can drive rapid forest compositional shifts. In boreal North America, black spruce shapes forest flammability and depends on fire for regeneration. This relationship has helped black spruce maintain its dominance through much of the Holocene. However, with climate change and more frequent and severe fires, shifts away from black spruce dominance have been demonstrated, with implications for ecosystem function. Forest resilience to disturbance is supported by multiple mechanisms, including ecological legacies affecting seed availability, species’ environmental tolerances, and biotic interactions. Understanding the relative importance of these mechanisms supports predictions of where and how disturbance will alter future forest resilience. In 2014, 2.85M ha of forest burned in the Northwest Territories, Canada, the largest fire season in its recorded history. To evaluate the impacts of this “megafire” year, observational and experimental studies have been combined to test mechanisms underlying black spruce resilience to increasing wildfire activity. These results demonstrate the vulnerability of black spruce to effects of increased fire activity that erode ecological legacies relating to seed availability and seedbed conditions. Generalities in these patterns and drivers were evaluated by synthesizing post-fire regeneration data from across boreal North America. Despite considerable remaining resilience in black spruce forests, these results suggest that increases in climate moisture deficits and fire activity will undermine this resilience, pushing boreal forests toward a tipping point that has not been crossed in several thousand years.

Jennifer Baltzer grew up in rural Nova Scotia and obtained a BSc degree at Acadia University. She was awarded a PhD by the University of Toronto for work in the Borneo jungle evaluating resource limitation in tropical trees. Following a post-doctoral fellowship at Harvard University, her first faculty position was at Mount Allison University. In 2011, she moved to Wilfrid Laurier University where she currently holds a Canada Research Chair in Forests and Global Change. Her research focuses on the impacts of global warming, including permafrost thaw, wildfire regimes and biome shifts, on the distribution and function of high latitude boreal forests and their implications for northern communities. Dr Baltzer works closely with the Government of NWT and collaborates with NASA and the Smithsonian Institution.

The meeting will be held at the Army Officers’ Mess, 149 Somerset St. W (between Elgin and Cartier streets), Ottawa. Parking is available in the Mess’s lot (Elgin Street side) and on the street. The meeting begins at 2000 hrs and the bar will be available from 1930 hrs. As always, guests are welcome.

Next meetings:
Feb 14    Barry Pottle: Towards a contemporary urban Inuit art photography
Mar 14    David Murray on the establishment of Northern national parks


HAPPY NEW YEAR!

Thomas Frisch
Secretary
613-725-2221; tfrisch@sympatico.ca



SPEAKERS PROGRAMME
2022-2023

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