Research interests
I am an ecosystem ecologist who uses a variety of field and laboratory techniques to understand and predict how ecosystems are shaped by climatic change. Specifically, I work at the root-soil interface to investigate how atmospheric and climatic change alters belowground carbon and nutrient cycling.
Education
Ph.D., 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
Appointments
Staff scientist (2010 – present)
Environmental Sciences Division
Oak Ridge National Laboratory
Post-doctoral research associate (2008 – 2010)
Environmental Sciences Division
Oak Ridge National Laboratory
Marvin L. Wesely Graduate Research Environmental Fellow (2007 – 2008)
Global Change Education Program
Department of Energy
Refereed publications
In press
McMurtrie RE, Iversen CM, Dewar RC, Medlyn BE, Näsholm T, Pepper DA, Norby RJ (2012). Plant root distributions and nitrogen uptake predicted by an hypothesis of optimal root foraging. Ecology and Evolution, in press.
Warren JM, Iversen CM, Garten CT, Norby RJ, Childs J, Brice DJ, Evans RM, Gu L, Thornton PE, Weston DJ (2012). Timing and magnitude of carbon partitioning through a young loblolly pine (Pinus taeda L.) stand using 13C labeling and shade treatments. Tree Physiology, DOI: 10.1093/treephys/tpr129.
2012
Iversen CM, Keller JK, Garten CT, Norby RJ (2012). Soil carbon and nitrogen cycling and storage throughout the soil profile in a sweetgum plantation after 11 years of CO2-enrichment. Global Change Biology 18: 1684-1697.
Iversen CM, Murphy MT, Allen MF, Childs J, Eissenstat DM, Lilleskov EA, Sarjala TM, Sloan VL, Sullivan PF (2012). Advancing the use of minirhizotrons in wetlands. Plant and Soil 352: 23–39.
2011
Iversen CM, Hooker TD, Classen AT, Norby RJ (2011). Net mineralization of N at deeper soil depths as a potential mechanism for sustained forest production under elevated [CO2]. Global Change Biology 17: 1130-1139.
Garten CT, Iversen CM, Norby RJ (2011). Litterfall 15N abundance indicates declining soil nitrogen availability in a free air CO2-enrichment experiment. Ecology 92: 133-139.
2010
Iversen CM (2010). Digging deeper: Fine root responses to rising atmospheric [CO2] in forested ecosystems. New Phytologist 186: 346-357.
Norby RJ, Warren JM, Iversen CM, Medlyn BE, McMurtrie RE (2010). CO2 enhancement of forest productivity constrained by limited nitrogen availability. Proceedings of the National Academy of Sciences, USA 107: 19368-19373.
Iversen CM, Bridgham SD, Kellogg LE (2010). Scaling plant nitrogen-use and uptake efficiencies in response to nutrient addition in peatlands. Ecology 91: 693-707.
Iversen CM, O’Brien SL (2010). Organized Oral Session 3. Missing links in the root–soil organic matter continuum. Bulletin of the Ecological Society of America 91: 54-64.
2009
O’Brien SL, Iversen CM (2009). Missing links in the root-soil organic matter continuum. New Phytologist 184: 513-516.
Franklin O, McMurtrie RE, Iversen CM, Crous KY, Finzi A, Tissue DT, Ellsworth DS, Oren R, Norby RJ (2009). Forest fine-root production and nitrogen use under elevated CO2: contrasting responses in evergreen and deciduous trees explained by a common principle. Global Change Biology 15: 132-144.
2008
Iversen CM, Ledford J, Norby RJ (2008). CO2 enrichment increases carbon and nitrogen input from fine roots in a deciduous forest. New Phytologist: 179: 837-847.
Iversen CM, Norby RJ (2008). Nitrogen limitation in a sweetgum plantation: Implications for carbon allocation and storage. Canadian Journal of Forest Research 38: 1021-1032.
2005 - 2007
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.
Keller JK, Bridgham SD, Chapin CT, Iversen CM (2005). Limited effects of six years of fertilization on carbon mineralization dynamics in a Minnesota fen. Soil Biology and Biochemistry 37: 1197-1204.
Grants and fellowships
| 2007 – 2009 |
Doctoral Dissertation Improvement Grant. Will CO2
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
| 2010 |
Finalist in New Phytologist Tansley Medal competition for mini-review: Iversen CM (2010), New Phytologist 186: 346-357. Highlighted in Woodward & Hetherington ‘The New Phytologist Tansley medal’, New Phytologist 186: 263-264. |
| 2009 |
Distinguished Achievement Award for Post-Graduate Research. Environmental Sciences Division, Oak Ridge National Laboratory. |
| 2007 – 2008 |
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, USA. |
| 2004 |
Travel award to attend Terrestrial Ecosystem Response to Atmospheric and Climatic Change annual meeting, Fort Meyers, FL, USA. |
| 2004 |
Travel award to attend Terrestrial Ecosystem Responses to Atmospheric and Climatic Change annual meeting, Fort Meyers, FL, USA. |
| 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, USA
(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 |
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 |
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 |
Undergraduate mentoring
| Summer, 2011 |
Jonathan Brooks, Hope College
The relaxation effect: Changes in fine-root distribution and soil C pools two years after the conclusion of a forested CO2-enrichment experiment |
| Summer, 2010 |
Heather Henderson, Volunteer State Community College
Soil moisture drives soil CO2 efflux in a loblolly pine stand
*Heather was chosen to compete in the 2010 Department of Energy, Science and Energy Research Challenge (SERCh) competition, hosted at Argonne National Laboratory, Argonne, IL, USA. |
| Fall, 2009 |
Faith Whitehouse, Hope College
Fine-root diameter distribution and standing crop from 0 to 90 cm depth under elevated [CO2]
*Faith was chosen to compete in the 2010 Department of Energy Science and Energy Research Challenge (SERCh) competition, hosted at Argonne National Laboratory, Argonne, IL, USA. She was also invited to attend the 2011 American Association for the Advancement of Science (AAAS) meeting in Washington, DC to present her paper, which was accepted in the Department of Energy's Journal of Undergraduate Research (Whitehouse and Iversen, 2011). |
| Summer, 2009 |
Lauren Stachowiak, University of Wisconsin, Whitewater
Rooting distribution and morphology under elevated [CO2]
*Lauren wrote a poem:
Roots!
You can…dig ‘em
You can sieve ‘em
You can pick ‘em
You can wash ‘em
Roots!
You can sort ‘em
You can dry ‘em
You can scan ‘em
You can store ‘em
Yeah! I love roots!
|
| 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 |
Presentations
Iversen CM, Norby RJ. 2012. Digging deeper: Rooting distributions in forested CO2-enrichment experiments. Invited talk. Scaling Root Processes: Global Impacts workshop, Washington, D.C.
Iversen CM, Norby RJ. 2011. The interplay between soil N availability, C partitioning, and ecosystem C storage in a CO2-enriched sweetgum plantation. Invited talk. The 27th New Phytologist Symposium: Stoichiometric flexibility in terrestrial ecosystems under global change. Biosphere 2, Oracle, AZ, USA
Iversen CM, Keller JK, Garten GT, Norby RJ. 2011. The consequences of deeper rooting distributions under elevated [CO2]. Organized oral session. Ecological Society of America annual meeting, Austin, TX, USA
Iversen CM. 2011. At the root of the response: Carbon and nitrogen cycling in a CO2-enriched deciduous forest. Invited talk. Oak Ridge Institute for Continued Learning, Philosophical Society, Oak Ridge, TN, USA.
Iversen CM. 2010. Digging deeper: fine-root responses to rising atmospheric CO2 concentration in forested ecosystems. Climate Change Science Institute, FIrst Annual Science Advisory Board Meeting, Oak Ridge National Laboratory, Oak Ridge, TN, USA. Poster presentation. [pdf]
Iversen CM. 2010. Digging deeper: Rooting distributions in CO2-enriched forests. Fifth International Symposium on Physiological Processes in Roots of Woody Plants, University of Victoria, Victoria, BC, Canada. Oral presentation.
Iversen CM. 2010. At the root of the response: Carbon and nitrogen cycling in a CO2-enriched deciduous forest. Invited talk. Biology Department, Hope College, Holland, MI, USA.
Iversen CM, Bridgham SD, Kellogg LE. 2009. Scaling plant nitrogen-use and uptake efficiencies in response to nutrient addition in peatlands. Second International PeatNet Symposium: Peatlands in the global carbon cycle, Prague, Czech Republic. Poster presentation. [pdf]
Iversen CM, Jastrow JD, and Norby RJ. 2009. Carbon and nitrogen inputs from decomposing roots into different soil organic matter fractions. Organized oral session. Ecological Society of America annual meeting, Albuquerque, NM, USA.
Iversen CM. 2009. The causes and consequences of increased fine-root production in a CO2-enriched sweetgum plantation. Invited talk. Biosciences Division Seminar, Argonne National Laboratory, Argonne, IL, USA.
Iversen CM. 2009. The causes and consequences of increased fine-root production in a CO2-enriched sweetgum plantation. Invited talk. Department of Biological Sciences Seminar, University of Illinois at Chicago, Chicago, IL, USA.
Iversen CM. 2008. The causes and consequences of increased fine-root production in a CO2-enriched sweetgum plantation. Keynote address. High CO2 Workshop, University of Western Sydney, New South Wales, Australia.
Iversen CM, Childs J, Norby RJ. 2008. CO2 enrichment increases carbon and nitrogen input from fine roots in a deciduous forest. Ecological Society of America annual meeting, Milwaukee, WI, USA. Oral presentation.
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., USA. Oral presentation.
Iversen CM. 2006. At the root of the response: Carbon and nitrogen cycling in a CO2-enriched
deciduous forest. Invited talk. Smithsonian Environmental Research Center, Edgewater, MD, USA.
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, USA. Winner of best student poster award, Soil Ecology Section.
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, USA.
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, USA. Oral presentation.
Iversen CM, and Norby RJ, and Gunderson CA. 2005. Nitrogen limitation and the potential for long-term effects on production and carbon storage in a CO2-enriched
forest. Ecological Society of America annual meeting, Montreal, Canada. Poster presentation.
Iversen CM, and Norby RJ. 2005. Nitrogen limitation and the potential for long-term effects on production and carbon storage in a CO2-enriched
forest. Soil Ecology Society bi-annual meeting, Argonne
National Laboratory, Argonne, IL, USA. Winner of second best student poster award.
Iversen CM, and Norby RJ. 2005. Nitrogen distribution and dynamics in a CO2-enriched
deciduous forest: Will N limitation preclude a sustained productivity response? TERACC Workshop, Modeling Ecosystem Respones to Global Change: Techniques and Recent Advances, Fort Myers, FL, USA
. Poster presentation.
Professional Activities
Organizer: "Advancing minirhizotron use to examine ephemeral root dynamics in peatland and high carbon ecosystems". Small workshop hosted at Oak Ridge National Laboratory, and funded by the Department of Energy, Office of Science, and New Phytologist.
Co-organizer: “Missing links in the root-soil organic matter continuum”. Organized oral session at the annual Ecological Society of America meeting, August, 2009 in Albuquerque, NM, USA.
Ad-hoc reviewer for: Acta Oecologica; Biological Invasions; Canadian Journal of Forest Research; Ecology; Ecosphere; Global Biogeochemical Cycles; Global Change Biology; Journal of Ecology; Nature; New Phytologist; Oecologia; Plant and Soil; Soil Biology and Biochemistry; Soil Science Society of America Journal; Tree Physiology; National Science Foundation; National Institute for Climate Change Research; Department of Energy, Office of Science.
Public tours: Oak Ridge National Laboratory Free-Air CO2-Enrichment experiment.
Public outreach: Local NPR interview; web cast for Oak Ridge Associated Universities; part of a feature story in the ORNL Review; presentation of “Ecosystems” and “Greenhouse effect” concepts to 3rd grade classrooms and Environmental Club in Sevierville, TN, USA; built decomposition columns with 6th, 7th, 8th-graders at Cherokee Middle School, Kingston, TN, USA, ORNL recruitment video, National Geographic JASON program.
Society memberships: Ecological Society of America, Soil Ecology Society.
Updated on 23 April 2012. |
