NOAA - UNIVERSITY OF
MICHIGAN GREAT LAKES SEMINAR
We have two upcoming seminars:
Date and Time:
Tuesday, September 18, 2007
Dr. Haejin Han (Jinny)
University of Michigan
School of Natural Resources and Environment
"Nutrient loading to Lake Michigan: a mass balance assessment"
I estimated nitrogen (N) loading to 25 watersheds of the Lake Michigan Basin (LMB) from 1920 to 2002 to examine temporal and spatial variation in net anthropogenic N inputs (NANI) in relation to land use, climate, and agricultural practices and to explore how well NANI and climate are able to predict temporal and spatial variation in river export of total N. Based on my accounting of net anthropogenic N inputs (NANI) due to fertilizer application, crop fixation, net atmospheric deposition, and net trade of N as food and feed, total NANI to the entire LMB increased nearly three-fold over the 20th Century. Watersheds with intense corn production in the eastern LMB experienced the largest (about six-fold) increase. Prior to 1944, temporal variation in total NANI to all watersheds was determined by changes in newly fixed N originating within the LMB, rather than new N inputs imported from outside the basin. However, from 1950 onward, total NANI to the LMB was increasingly influenced by a variety of types of transported or traded N, and the relative importance of individual N sources subsequently became more heterogeneous across watersheds. By the late 20th Century, atmospheric N deposition was the major input to forested regions, crop N fixation was the largest input to agricultural watersheds of western LMB, and fertilizer N application dominated agricultural watersheds of the eastern LMB.
To determine how well riverine export of total N (TN) can be predicted from N inputs to the land, I compared linear and log-linear regression models predicting riverine TN exports for 18 selected watersheds over five census years from 1974 -1992, using a number of different N budgeting approaches. Various assumptions and computational details influenced model fit and prediction errors, and statistical relationships were improved, especially for small watersheds with diverse land use and farming practices, in response to specific model adjustments. NANI estimation procedures that account for seasonal fluctuations in livestock populations, and estimate crop N fixation using crop yield methods rather than area harvested, resulted in stronger models. A non-linear regression model that simultaneously incorporated spatial and temporal data for the preferred NANI model as well as annual runoff was able to account for 87% of the variation in riverine TN exports over time and space. This model, based on a more detailed description of N sources and losses and annual runoff, and incorporating both temporal and spatial variation, was found to have lower bias and higher precision in the prediction of riverine TN exports.
* * * * * * *
Date and Time:
Tuesday, September 25, 2007
Dr. Jessica Head
National Wildlife Research Centre, Ottawa
"Genetic and molecular approaches for assessing health of Great Lakes birds"
The Canadian Wildlife Service (CWS) has monitored the health of colonial fish-eating birds in the Great Lakes for over 30 years. Annual surveys conducted by CWS biologists have provided us with a continuous record of reproductive success and environmental contaminant levels in herring gull eggs since the early 1970s. More recently, molecular and biochemical techniques with practical applications to wildlife health assessment have become an important part of the monitoring program. In this talk, I will review basic concepts of molecular genetics, and then describe relevant ongoing research by our group in this field. Molecular techniques for determining sex, chronological age and contaminant sensitivity in birds will be discussed. In each case, our work has led to collaborative projects which use molecular biological methods to address questions in avian ecology and population health assessment.
GLERL, Conference Room 105
2205 Commonwealth Blvd
Ann Arbor, MI
For directions, see
-- David F. Reid, Ph.D. Director, NOAA National Center for Research on Aquatic Invasive Species (NCRAIS) Senior Research Scientist, Nonindigenous Species Program U.S. Department of Commerce National Oceanic and Atmospheric Administration Great Lakes Environmental Research Laboratory 2205 Commonwealth Blvd. Ann Arbor, MI 48105-2945 Voice: 734-741-2019 FAX: 734-741-2055 GLERL home page: http://www.glerl.noaa.gov
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * glin-announce is hosted by the Great Lakes Information Network (GLIN): http://www.great-lakes.net To subscribe: http://www.glin.net/forms/glin-announce_form.html To post a message: http://www.glin.net/forms/glin-announce_post.html To search the archive: http://www.glin.net/lists/glin-announce/ All views and opinions presented above are solely those of the author or attributed source and do not necessarily reflect those of GLIN or its management. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *