Question:
I read an article recently that said certain animal species are moving northward at a measurable rate, a km or so a year if I remember This leads me to ask if the tree line is moving north in Canada or higher up mountains where this exists. And are species changing in the forests?
Answer:
Thank you for your question. Many scientists at the Government of Canada work towards exploring this very question, particularly within the Canadian Forest Service (CFS). A number of studies outside of the CFS have recorded modest shifts northwards in distribution of tree and forest animal species. The CFS has worked on projecting future shifts based on climate scenarios, as well as examining adaptation options to reduce the impact of climate change on Canada’s forests.
Dan McKenney (Chief, Landscape Analysis and Applications) and his team have created an interactive map which displays current distributions of habitat for plant species (http://planthardiness.gc.ca/), and have been working towards projecting future range limits of tree species across Canada (http://planthardiness.gc.ca/index.pl?m=16&lang=en).
A group of scientists, led by Catherine Ste-Marie (CFS Climate Change Research Coordinator), recently published a special issue on Assisted Migration (Forestry Chronicle, Nov/Dec 2011 – http://pubs.cif-ifc.org/toc/tfc/87/06#d131019e134), examining the possibility of moving tree species north in order to help them adapt to climate change. Although all of the articles address current tree species movement to some degree, Richard Winder’s article on “Ecological implications for assisted migration in Canadian forests” covers the scientific evidence in the most detail.
I hope this has been helpful and please do not hesitate to follow-up on these answers.
-Catherine Ste-Marie, Ph.D.
Ask a Scientist: Weight at the Equator
Question:
What would be the difference in my weight (force) between standing at the equator vs standing at one of the poles? I suspect I would weigh less at the equator due to the centrifugal force. Say I weigh 80 kg.
Answer:
At first glance, yes you would weigh a very small amount less at the equator, but one day of over-eating on the airplane to the pole, or of strenuous sweating exercise, will easily mask the predicted weight difference. This answer considers the effect of rotation at the equator, that uses “approximate values” for factors, and ignores the non-spherical nature of the earth and other effects. This simple approach compares
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