Image of Colleen Iversen.

Colleen M Iversen

Distinguished Staff Scientist and Group Leader (Plant-Soil Interactions Group)

About me

I am the Director of the NGEE Arctic project, a lead investigator of the Fine-Root Ecology Database (FRED), and I previously led the Belowground Tasks component of the SPRUCE project. I am also an Associate Editor at the international plant journal New Phytologist and an elected Early Career Fellow of the Ecological Society of America, and I was a member of the inaugural cohort of ‘New Voices’ at the National Academies of Sciences, Engineering, and Medicine. I grew up exploring the fields and farms of mid-Michigan, and I received my BS at Hope College. I continued to move southward for my graduate work, receiving my MS at the University of Notre Dame and my PhD at the University of Tennessee in Knoxville. I see science communication as the foundation for a shared understanding of society’s future, and I have shared my scientific vision on Public Radio International’s ‘Science Friday’, and in the Alda School’s ‘Flame Challenge’, as well as in organized symposia, sessions, and workshops. For more information, visit and 

Recent publications of interest

Please see for more publications!

Iversen CM, Latimer J, Brice DJ, Childs J, Vander Stel HM, Graham J, Griffiths N, Malhotra A, Norby RJ, Olehieser K, Phillips J, Salmon VG, Sebestyen SD, Yang X, Hanson PJ. 2023. Whole-ecosystem warming increases plant-available nitrogen and phosphorus in the SPRUCE bogEcosystems 26: 86-113. Highlighted here ​by the Department of Energy's Office of Science!

Wang B, McCormack ML, Ricciuto D, Yang X, Iversen CM. 2023. Embracing fine-root system complexity to improve the predictive understanding of ecosystem functioningGlobal Change Biology 29: 2871 – 2885. See a commentary of Bin’s paper here!

Weber S, Iversen CM. 2023. How deep should we go to understand roots at the top of the world? New PhytologistEarly View. This was a Commentary on the very cool paper by Blume-Werry et al. 2023 on predicting Arctic rooting depth distribution. 

Weigelt A, Mommer L, Andraczek K, Iversen CM, Bergmann J, Bruelheide H, Freschet GT, Guerrero-Ramírez NR, Kattge J, Kuyper TW, Laughlin DC, Meier IC, van der Plas F, Poorter H, Roumet C, van Ruijven J, Maria Sabatini F, Semchenko M, Sweeney CJ, Valverde-Barrantes OJ, York LM, McCormack ML. 2023. The importance of trait selection in ecologyNature (Matters Arising), 618: E29-E30. 

Defrenne CE, Childs J,  Fernandez CW, Taggart M,  Nettles WR, Allen MF,  Hanson PJ, Iversen CM. 2021. High‐resolution minirhizotrons advance our understanding of root‐fungal dynamics in an experimentally warmed peatlandPlants People Planet 3: 640 - 652. Part of a Special Issue on Mycorrhizas for a Changing World

Freschet GT, Pagès L, Iversen CM, et al. 2021. A starting guide to root ecology: strengthening ecological concepts and standardizing root classification, sampling, processing and trait measurementsNew Phytologist 232: 973 - 1122.

Iversen CM, McCormack ML. 2021. Filling gaps in our understanding of belowground plant traits across the world: An introduction to a Virtual IssueNew Phytologist 231: 2097 - 2103. This is an introduction to a Virtual Special Issue that highlights new belowground understanding gained from more than 40 awesome papers published in New Phytologist over just the last 2 years! 

Weigelt A, Mommer L, Andraczek K, Iversen CM, et al. 2021. An integrated framework of plant form and function: The belowground perspectiveNew Phytologist 232: 42 - 59. 

Bergman J, Weigelt A, van der Plas F, Laughlin DC, Kuyper TW, Guerrero-Ramirez N, Valverde-Barrantes OJ, Bruelheide H, Freschet GT, Iversen CM et al. 2020. The fungal collaboration gradient dominates the root economics space in plantsScience Advances 6: eaba3756. 

Iversen CM, Bolton WR, Rogers A, Wilson CJ, Wullschleger SD. 2020. Building a culture of safety and trust in team scienceEos 101. 

Malhotra A, Brice D, Childs J, Graham JD, Hobbie EA, Vander Stel H, Feron SC, Hanson PJ, Iversen CM. 2020. Peatland warming strongly increases fine-root growthPNAS 117: 17627 - 17634. Highlighted by Science Magazine, and also here by ORNL!

Iversen CM. 2019. New Phytologist Associate Editor ProfileNew Phytologist 223: 530 - 531. 

Iversen CM, Childs J, Norby RJ, Ontl TA, Kolka RK, Brice DJ, McFarlane KJ, Hanson PJ. 2018. Fine-root growth in a forested bog is seasonally dynamic, but shallowly distributed in nutrient-poor peat. Plant and Soil 424: 123-143.

Iversen CM, McCormack ML, Powell AS, Blackwood CB, Freschet GT, Kattge J, Roumet C, Stover DB, Soudzilovskaia NA, Valverde-Barrantes OJ, van Bodegom PM, Violle C. 2017. Viewpoints: A global Fine-Root Ecology Database to address belowground challenges in plant ecology. New Phytologist 215: 15-26.

Iversen CM, Sloan VL, Sullivan PF, Euskirchen ES, McGuire AD, Norby RJ, Walker AP, Warren JM, Wullschleger SD. 2015. The unseen iceberg: Plant roots in arctic tundra (Tansley Review). New Phytologist 205: 34-58.

McCormack ML, Dickie IA, Eissenstat DM, Fahey TJ, Fernandez CW, Guo D, Helmisaari H-S, Hobbie EA, Iversen CM, et al. 2015. Redefining fine roots improves understanding of below-ground contributions to terrestrial biosphere processes (Tansley Review). New Phytologist 207: 505-518.

2023 - Present

Director, NGEE Arctic project
Funded by: Biological and Environmental Research program
Office of Science, United States DOE

2021 - 2023

Deputy Director, NGEE Arctic project
Funded by: Biological and Environmental Research program
Office of Science, United States DOE

​​2020 - Present

Group Leader, Plant - Soil Interactions Group
Environmental Sciences Division 
Oak Ridge National Laboratory

2016 - 2023

Theme lead, Integrated Ecosystem Sciences
Climate Change Science Institute
Oak Ridge National Laboratory

Please see for more information!

Highly Cited Researcher, Web of Science Group, Clarivate Analytics​​ (2019 - 2022)
‘In recognition of exceptional research performance demonstrated by production of multiple highly cited papers that rank in the top 1% for field and year in Cross-Field.’

Science Communicator Award, UT-Battelle Awards Night (2019)
‘In recognition of Colleen’s many contributions to science communication and outreach, and to her ability to present science in a compelling manner to audiences of all ages.'

Director’s Award for Outstanding Individual Accomplishment in Mission Support, UT-Battelle Awards Night (2019)
‘Among the many achievements recognized at the 2019 UT-Battelle Awards Night, yours was selected as an exceptional contribution to our success.'

Inaugural cohort, New Voices in Sciences, Engineering, and Medicine (2018 - 2020)
'The National Academies of Sciences, Engineering, and Medicine are launching the 'New Voices in Sciences, Engineering, and Medicine' initiative to identify outstanding early-career science, engineering, and medicine (SEM) leaders. They will engage in communicating the evidence base for addressing national and global challenges to provide new perspectives on issues of importance to the community represented by the National Academies, and to help identify ways to expand the diversity of expertise that is brought to all of the Academies' convening and advisory activities.'

Early Career Fellow of the Ecological Society of America (2017 - 2021)
'Elected for her leadership and creativity in linking experimentation and modeling to advance ecological understanding of the influence of fine plant roots on the fate of vast pools of carbon and nutrients held in the soils of diverse biomes.'​

Stanley I. Auerbach Early-Career Award for ​Excellence in Environmental Sciences (2012)
​Environmental Sciences Division, Oak Ridge National Laboratory

Finalist in New Phytologist Tansley Medal competition (2010)
Digging deeper: Fine-root responses to rising atmospheric CO2 concentration in forested ecosystems'.
Highlighted in The New Phytologist Tansley medal

Distinguished Achievement Award for Post-Graduate Research (2010)
Environmental Sciences Division, Oak Ridge National Laboratory

2003 - 2008

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

2001 - 2004

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

1997 - 2001

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

2022 - Present

Distinguished Staff Scientist
Climate Change Science Institute and 
Environmental Sciences Division 
Oak Ridge National Laboratory

​​2016 - 2022

Senior Staff Scientist
Climate Change Science Institute and 
Environmental Sciences Division ​ 
Oak Ridge National Laboratory

2012 - 2016

Staff Scientist
Climate Change Science Institute and 
Environmental Sciences Division ​ 
Oak Ridge National Laboratory

2010 - 2012

Associate Staff Scientist 
Environmental Sciences Division ​ 
Oak Ridge National Laboratory

2008 - 2010

Post-doctoral research associate 
Environmental Sciences Division ​
Oak Ridge National Laboratory