Colleen M. Iversen

Education

Ph.D. Candidate, University of Tennessee (2003 – 2008)
Ecology and Evolutionary Biology
Co-advisors: Richard J. Norby and Aimée T. Classen
Dissertation: Forest responses to rising atmospheric CO2: Causes and consequences of increased fine-root production in a CO2-enriched sweetgum plantation

M.S., University of Notre Dame (2001 – 2004)
Biological Sciences
Advisor: Scott D. Bridgham
Thesis: Scaling community nitrogen use- and uptake efficiencies in response to increased nutrient availability in peatlands

B.S. (cum laude), Hope College (1997 – 2001)
Biological and Environmental Sciences

Refereed publications

Iversen CM, Ledford J, Norby RJ (in press). CO2-enrichment increases carbon and nitrogen input from fine roots in a deciduous forest. New Phytologist.

Iversen CM, Norby RJ (in press). Increases in nitrogen uptake rather than nitrogen-use efficiency support higher rates of temperate forest productivity under elevated CO2. Canadian Journal of Forest Research.

Finzi AC, Norby RJ, Calfapietra C, Gallet-Budynek A, Gielen B, Holmes WE, Hoosbeek MR, Iversen CM, Jackson RB, Kubiske MB, Ledford J, Liberloo M, Oren R, Polle A, Pritchard S, Zak DR, Schlesinger WH, Ceulemans R. 2007. Increases in nitrogen uptake rather than nitrogen-use efficiency support higher rates of temperate forest productivity under elevated CO2. Proceedings of the National Academy of Sciences, USA 104: 14014-14019.

Norby RJ, Iversen, CM. 2006. Nitrogen uptake, distribution, turnover, and efficiency of use in a CO2-enriched sweetgum forest. Ecology 87:5-14.

Keller JK, Bauers, AK, Bridgham, SD, Kellogg, LE, Iversen, CM. 2006. Nutrient control of microbial carbon cycling along an ombrotrophic-minerotrophic peatland gradient. Journal of Geophysical Research 111: G03006.

Manuscripts in review

Franklin O, McMurtrie RE, Iversen CM, Crous KY, Finzi A, Tissue D, Ellsworth D, Oren R, Norby RJ (in review). Forest fine-root production and nitrogen use under elevated CO2: Contrasting responses in evergreen and deciduous trees explained by a common principle

Grants and fellowships

2007 – 2009	Doctoral Dissertation Improvement Grant. Will CO`2` mediated increases in fine-root litter progressively decrease forest N availability by increasing N immobilization in soil organic matter? *National Science Foundation* ($11,730).
2005 – 2008	Graduate Research Environmental Fellowship. Global Change Education Program, *United States Department of Energy* ($19,600 annually).
2005	Ehleringer Stable Isotope Ecology course at the University of Utah. Tuition grant from Department of Ecology and Evolutionary Biology, University of Tennessee ($1300).
2004	Summer Research Grant. Department of Ecology and Evolutionary Biology, University of Tennessee ($1300).

Honors and awards

2007 – 2008	Marvin L. Wesely Graduate Research Environmental Fellow. Global Change Education Program, United States Department of Energy.
2006	Marvin L. Wesely Graduate Research Environmental Fellow. Global Change Education Program, United States Department of Energy.
2006	Travel award from Terrestrial Ecosystem Responses to Atmospheric and Climatic Change network to attend forested FACE synthesis in Antwerp, Belgium.
2005	Second best student poster presentation. Soil Ecology Society biennial meeting, Argonne National Laboratory, Argonne, IL.
2004	Travel award to attend Terrestrial Ecosystem Response to Atmospheric and Climatic Change annual meeting, Fort Meyers, FL.
2004	Travel award to attend Terrestrial Ecosystem Responses to Atmospheric and Climatic Change annual meeting, Fort Meyers, FL.
2003	Travel awards from the Society of Wetland Scientists to attend Society of Wetland Scientists annual meeting, New Orleans, LA (2003) and Association of Southeastern Biologists annual meeting, Memphis, TN (2004).

Teaching and mentoring

Instructor

Spring, 2008

“Ecology in a changing world”
Designed and co-taught 1-credit undergraduate seminar
Department of Ecology and Evolutionary Biology
University of Tennessee

Teaching assistant

2003 – 2004	“Biodiversity” laboratory Department of Ecology and Evolutionary Biology University of Tennessee
2001 – 2002	“General Ecology” laboratory Department of Biological Sciences University of Notre Dame

Guest lecturer

2003 – 2007

Multiple-section “General Ecology” course on topics related to ecosystems, nutrient cycling, and trophic dynamics.
Department of Ecology and Evolutionary Biology,
University of Tennessee

Undergraduate mentoring

Fall, 2007	Jennifer Burks, Earlham College Mycorrhizal production and decomposition under elevated carbon dioxide concentrations
Summer, 2006	Caitlin Guthrie, Pomona College Elevated carbon dioxide does not affect net nitrogen mineralization
Fall, 2005	Joey Roberts, Middle Tennessee State University Disentangling fine-root production under elevated carbon dioxide concentrations using a stable carbon isotope
Summer, 2005	Zara Berg, Montana Tech Nitrogen fertilization effects on a forest understory

Selected presentations (2005-2007)

Iversen CM. 2007. At the root of the response in a CO2-enriched deciduous forest. M.L. Wesely Graduate Research Environmental Fellow, Global Climate Education Program, annual end-of-year meeting, Washington, D.C. Oral presentation.

Iversen CM. 2006. The root of the response: Changes in forest carbon and nitrogen cycling in a CO2-enriched deciduous forest. Invited talk. Smithsonian Environmental Research Center, Edgewater, MD.

Iversen CM, Norby, RJ and Classen, AT. 2006. Changes in fine-root quantity and quality with elevated CO2: Implications for decomposition and nitrogen cycling. Ecological Society of America annual meeting, Memphis, TN.Winner of best student poster award.

Iversen CM. 2006. Plant nitrogen use from fens to forests: Consequences for carbon storage. Invited talk. Oak Ridge National Laboratory weekly “Fishheads” meeting, Oak Ridge, TN.

Iversen CM, Norby, RJ and Classen, AT. 2006. Nitrogen cycling in a CO2-enriched deciduous forest: Implications for carbon storage. Global Change Education Program, Graduate Research Environmental Fellowship annual orientation, Portland, OR. Oral presentation.

Iversen CM, and Norby, RJ. 2005. Nitrogen cycling and dynamics in a CO2-enriched deciduous forest: Will nitrogen limitation preclude a sustained productivity response? Soil Ecology Society bi-annual meeting, Argonne National Laboratory, Argonne, IL.Winner of second best student poster award.

Iversen CM, and Norby, RJ. 2005. Nitrogen cycling and dynamics in a CO2-enriched deciduous forest. Terrestrial Ecosystem Responses to Atmospheric and Climatic Change annual meeting, Fort Meyers, FL. Poster presentation.

Professional Activities

Ad-hoc reviewer for: New Phytologist, Plant and Soil, Acta Oecologica, Canadian Journal of Forest Research and National Science Foundation, Ecosystems Panel.

Public tours: Oak Ridge National Laboratory Free-Air CO2-Enrichment experiment.

Public outreach: Local NPR interview, a web cast for Oak Ridge Associated Universities, and as part of a feature story in the ORNL Review.

Society memberships: American Association for the Advancement of Science, American Geophysical Union, Association of Southeastern Biologists, Ecological Society of America, Society of Soil Ecologists Society of Wetland Scientists, Soil Science Society of America.

References

Dr. Richard J. Norby
Corporate Fellow
Environmental Sciences Division
Oak Ridge National Laboratory
One Bethel Valley Road,
Bldg. 1062
Oak Ridge TN 37831
(865) 576-5261
norbyrj at ornl.gov

Dr. Aimée T. Classen
Assistant Research Professor
Department of Ecology and Evolutionary Biology
University of Tennessee
569 Dabney Hall
Knoxville, TN 37996
(865) 574-7848
aimee.classen at utk.edu

Dr. Scott D. Bridgham
Associate Professor
Center for Ecology and Evolutionary Biology
University of Oregon
5289 University of Oregon
Eugene, OR 97403
(541) 346-1466
bridgham at uoregon.edu

Updated on April 29, 2008.