Life Science Hour Seminar Series

Name:Jessie Young
 Research Faculty. International Arctic Research Center, UAF.
Title:Boreal forest water cycling: Deciduous trees put the eco in ecohydrology
Date:Friday, 22 March 2013
Location:Elvey Auditorium, 124 Elvey Building



One uncertainty in boreal forest hydrology is the role of vegetation water use in removing
and / or storing water, thereby affecting water availability for stream flow. The drastically
different tree communities that occupy the boreal landscape make it important to
understand their role in the water cycle. My seminar will focus on the water use dynamics
of the two primary tree types of the boreal forest: deciduous and coniferous trees. I
integrated different aspects of an extensive field study conducted at Caribou Poker Creeks
Research Watershed using a Bayesian analysis approach. I will show that the deciduous
trees found on south facing slopes without permafrost play a much more active role in the
water cycle compared to the coniferous trees on north facing slopes with permafrost. The
deciduous trees have higher water use and flux rates than the coniferous trees, resulting
in vertically controlled water pathways on south facing slopes wherein water is removed
from the soil and transpired into the atmosphere. The coniferous trees have much lower
water use and flux rates, resulting in horizontally controlled water pathways on north
facing slopes. This work is part of a broader project aimed at quantifying the uncertainties
in boreal forest hydrology to better predict potential changes due to permafrost thaw and
climate change.

About the Speaker:


I am a research faculty in IARC, where I also did my second postdoc with an OPP fellowship
focusing on the water use of plants in relation to permafrost thaw. I am interested in the
link between the carbon and water cycles in semi-arid systems, including the boreal forest.
In particular, I’m interested in the role of stable vs. ephemeral water sources in sustaining
ecosystem function during stressful periods, and the role of climate change in impacting
the availability of stable and ephemeral water sources. In terms of my background, my first
postdoc was at the University of Wyoming, where I learned how to use Bayesian statistics
to model soil respiration and plant physiological processes. I completed my PhD in Ecology
and Evolutionary Biology with a minor in Global Change at the University of Arizona in
2006, and I received a BS in Biology from Fort Lewis College in 2000.

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