Project Summary: Biogeochemical Transformations of Ancient Wood Beneath a High
Arctic Glacier, Ellesmere Island, Canada.
Currently, there is a great deal of scientific interest in determining how organic material is cycled
over long time scales so that we can understand how the global climate system has worked in
the
past, and how it might be expected to react to current human activities in the future.
From 55 to 24 million years ago, the Canadian high arctic ecosystem was covered with plants
and
animals that were much different from those that exist there today. Evidence of this past
ecosystem is preserved as “fossil forests” at various locations in the Canadian Arctic including
Axel Heiberg Island, Ellesmere Island and Cornwall Island. The analysis of the “fossil” plant
community structure at these sites has revealed that the high arctic ecosystem was
characterized
by abundant forests that are similar to present day swamps that are currently found at much
lower
latitudes.
Previous scientific investigations have used “molecular” techniques to determine how this
ancient
plant material has degraded over extended periods of time. The recent discovery of a retreating
glacier (referred to here as Glacier A) that is exposing wood of similar structure to that which is
found at other fossil forest sites in the high arctic provides the unique opportunity to determine
how this ancient vegetation degrades over millions of years under glaciers. For example, does a
glacier totally preserve overrun organic matter or does the organic matter continue to be
degraded
by microorganisms living beneath the glacier, and if so, what sort of compounds are released to
the environment when the glacier melts? To answer these questions, we propose to sample
some
of the ancient vegetation that is being exposed at Glacier A and characterize it using the same
molecular techniques that were used to characterize the vegetation at other fossil forest sites.
Glacier A is an unnamed glacier which is located to the east of Airforce Glacier, Quttinirpaaq
National Park (813202N, 761548W). We propose to visit the Glacier A site during the
summer of 2008 and sample some of this ancient vegetation. Sampling will be conducted by our
team of 3 researchers from the University of Alberta and will take place over a single day. We
anticipate collecting no more than 5 kg of wood and 3 kg of the surrounding soil.
This project is of particular importance given the recent discovery that glaciers may have
overrun,
considerable stores of organic matter. For example, the Greenland Ice Sheet overran the
vegetation and organic carbon stores of a boreal forest ecosystem. If glaciers continue to melt,
then the organic material that they currently overlie will be re-introduced to the environment.
Currently, there is very little understanding of how organic matter is altered beneath glaciers and
what compounds are released during glacier melt. Our proposed investigation will provide
information regarding the characteristics of organic matter degradation beneath glaciers, and
the
types of compounds that are generated in glacier systems and released to the environment
when
glaciers melt. It is in this way that northern communities will benefit from our research because
the nutrients released by melting glaciers will influence the re-growth of plants in front of glaciers
and may provide favourable grazing habitat for foraging animals such as hare, caribou and
muskox.
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Project Summary: Biogeochemical Transformations of Ancient Wood