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![Great Lakes Forestry Centre](/web/20061103011256im_/http://www.glfc.cfs.nrcan.gc.ca/images/insideheaderbr_e.jpg)
Science > Forest Hydrology
Forest Hydrology - Great
Lakes/St Lawrence Region
Study Leader: Fred Beall
fbeall@NRCan.gc.ca
Study Description:
Research at the Turkey Lakes Watershed (TLW) began in 1980 in response
to concerns over the impacts of airborne pollutants, primarily acidifying
substances, on forested ecosystems. From the outset, the project was envisioned
to be multi-disciplinary, bringing together researchers in meteorology,
biogeochemistry, forestry,
hydrology, fish and wildlife, and ecology to understand the aquatic and
terrestrial effects of acidic deposition. As environmental issues have
evolved over the last twenty years so has research at the TLW. In addition
to ongoing monitoring and research on the impacts of acid deposition,
there is research on the storage and release of toxic compounds, the manipulation
of fish habitat to simulate shoreline development, the evaluation of the
effects of climate change/variation, and the impacts of alternative forest
harvesting techniques on terrestrial and aquatic systems.
This study has amassed a 20-year data record of flow and chemistry for
13 first-order
streams, one of the longest records in Canada, and has contributed significantly
to a number of budgeting and modelling efforts. Ongoing data collection
includes continuous measurement of stream flow, concentration of the major
ions, nutrients and metals, and concentrations of dissolved organic and
inorganic carbon. The continued collection and maintenance of the data
set is central to this study. Recently reported results show that there
is substantial variation between the individual basins in their response
to declining acid deposition and changes in climate. We have observed
a significant trend in declining water yield from the basins even though
precipitation has remained relatively constant. Because of the number
of basins monitored and their inherent variability Turkey Lakes is a unique
site to study the interactions of climate, disturbance, topography, vegetation,
and soils. Four of our gauged basins were included in the harvesting experiment
initiated in 1997. Combined with the extensive pre-harvest data, we will
be able
to accurately determine the hydrochemical response of these basins to
harvesting and follow their recovery. This will provide useful knowledge
for the development of criteria and indicators of forest harvesting impacts
and the data required to develop and validate models. An expanding component
of this study addresses questions related to the development of predictive
tools. As forest managers and policy makers demand answers to questions
of greater scope and complexity, there is a need to develop more general
tools that can be applied across the landscape. Traditional empirical
models are not suited to the task. What is required is process-based models
that accurately characterize the "drivers" so they can be scaled
to suit the question at hand. The current focus in this area is the development
of a database system to improve the accessibility to and reliability of
our long-term data. This will provide the foundation to begin assessing
and/or developing models of hydrochemical processes at Turkey Lakes.
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