Research Associate: Stable Isotopes and Biogeochemistry

Larry Flanagan larry.flanagan at
Mon Apr 3 17:01:09 EST 2000


There is a position available immediately for a research associate to be
involved with ecosystem studies of carbon and water cycling in grassland
and boreal forest environments. The research involves a combination of
gas exchange (eddy covariance and chamber techniques) and stable isotope
analyses to improve our understanding of processes, and to quantify the
components contributing to total ecosystem carbon and water budgets. A
list of example publications is provided below.

The stable isotope facility consists of a Finnigan MAT Delta-Plus
isotope ratio mass spectrometer with dual inlet and continuous-flow
interfaces; and a CE carbon and nitrogen elemental analyzer. In
addition, there are a variety of off-line preparation systems including
systems to: (i) purify carbon dioxide from air and organic samples; (ii)
extract water from plant and soil samples; (iii) equilibrate carbon
dioxide with water samples; (iv) purify cellulose from wood samples.

The successful candidate will be expected to perform a variety of stable
isotope analytical procedures; instruct students in stable isotope
techniques; collect and process data in support of lab research

Some field work will be required. In addition to the prime
responsibilities of managing the stable isotope facility, the successful
candidate will help with the maintenance and data processing from our
ecosystem carbon dioxide and water flux studies (using the eddy
covariance technique as part of the Ameriflux program).

- An individual capable of independent work, with strong oral and
written communication skills
- A minimum of a  B.Sc. degree in Chemistry, Earth Science, Ecology,
or a related field.
- Experience with stable isotope analytical techniques including the
operation and routine maintenance of an isotope ratio mass spectrometer.
- Competence with electronics trouble-shooting and repair.
- Previous training or experience with carbon and water cycle studies
involving gas exchange techniques would be a strong asset.

Salary is dependent on qualifications and relevant experience. Secure
funding is currently available for a minimum of four years.

Please send an application letter describing qualifications and
experience; along with a CV; and the names, addresses, and e-mail
addresses of three references to:

Dr. L.B. Flanagan
Department of Biological Sciences
University of Lethbridge
4401 University Drive
Lethbridge, Alberta

Telephone:      (403) 380-1858
FAX:            (403) 329-2082
e-mail:         larry.flanagan at
WEB page:

Selected List of Relevant Publications:

Flanagan, L.B. and J.R. Ehleringer. 1998. Ecosystem - atmosphere CO2
exchange: interpreting signals of change using stable isotope ratios.
Trends in Ecology and Evolution 13: 10-14.

Flanagan, L.B., D.S. Kubien and J.R. Ehleringer. 1999. Spatial and
temporal variation in the carbon and oxygen stable isotope ratio of
respired CO2 in a boreal forest ecosystem. Tellus 51B: 367-384.

Flanagan, L.B., J.R. Brooks, G.T. Varney and J.R. Ehleringer. 1997.
Discrimination against C18O16O during photosynthesis and the oxygen
isotope ratio of respired CO2 in boreal forest ecosystems. Global
Biogeochemical Cycles 11: 83-98.

Flanagan, L.B., J.R. Brooks, G.T. Varney, S.C. Berry and J.R.
Ehleringer. 1996. Carbon isotope discrimination during photosynthesis
and the isotope ratio of respired CO2 in boreal forest ecosystems.
Global Biogeochemical Cycles 10: 629-640.

Farquhar, G.D., J. Lloyd, J.A. Taylor, L.B. Flanagan, J.P. Syvertsen,
K.T. Hubick, S.C. Wong and J.R. Ehleringer. 1993. Vegetation effects on
the oxygen isotopic composition of atmospheric CO2 Nature 363: 439-443.

Flanagan, L.B. 1998. Oxygen isotope effects during CO2 exchange: from
leaf to ecosystem processes. In Stable isotopes: integration of
biological, ecological and geochemical processes. Ed. H. Griffiths. BIOS
Scientific Publishers, Oxford, UK, pp. 185-201.

Rochette, P., D.A. Angers and L.B. Flanagan. 1999. Maize residue
decomposition measurement using soil-surface CO2 fluxes and natural
abundance of 13C. Soil Science Society of America Journal 63: 1385-1396.

Rochette, P., L.B. Flanagan and E.G. Gregorich. 1999. Separating total
soil respiration into plant and soil components using analyses of
natural abundance of 13C. Soil Science Society of America Journal 63:

Rochette, P. and L.B. Flanagan. 1997. Quantifying rhizosphere
respiration in a corn crop under field conditions. Soil Science Society
of America Journal 61: 466-474.

Johnsen, K.H., L.B. Flanagan, D.A. Huber and J.E. Major. 1999. Genetic
variation in growth, carbon isotope discrimination and foliar N
concentration in Picea mariana: analyses from a half-diallel mating
design using field grown trees. Canadian Journal of Forest Research 29:

Flanagan, L.B. and K.H. Johnsen. 1995. Genetic variation in carbon
isotope discrimination and its  relationship to growth under field
conditions in full-sib families of Picea mariana. Canadian Journal of
Forest Research 25: 39-47.

Brooks, J.R., L.B. Flanagan and J.R. Ehleringer. 1998. Responses of
boreal conifers to climate fluctuations: indications from tree-ring
widths and carbon isotope analyses. Canadian Journal of Forest Research
28: 524-533.

Williams, T.G., L.B. Flanagan and J.R. Coleman. 1996. Light and humidity
effects on photosynthetic gas exchange and discrimination against 13CO2
and C18O16O in tobacco plants modified by an antisense construct to have
low chloroplast carbonic anhydrase. Plant Physiology 112: 319-326.

Williams, T.G. and L.B. Flanagan. 1996. Effect of changes in water
content on photosynthesis, transpiration and discrimination against
13CO2 and C18O16O in Pleurozium and Sphagnum. Oecologia 108: 38-46.

Flanagan, L.B., J.R. Ehleringer and J.D. Marshall. 1992. Differential
uptake of summer precipitation among co-occurring trees and shrubs in a
pinyon-juniper woodland. Plant, Cell and Environment 15: 831-836.

Flanagan, L.B. 1993. Environmental and biological influences on the
stable oxygen and hydrogen isotopic composition of leaf water. In:
Stable isotopes and plant carbon/water relations. Eds. J.R. Ehleringer,
A.E. Hall and G.D. Farquhar. Academic Press, San Diego, California. pp.


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