Contact Information

The Jahren Laboratory is located

at the University of Oslo 

4th Floor, Kristine Bonnevies hus,

Blindern Campus


Mailing address:

c/o CEED, Postbox 1028 Blindern

N-0315 Oslo, Norway

Research by Topic

All peer-reviewed: * denotes student author; # denotes post-doctoral  author; % denotes senior lab member.

The Carbon Isotope Composition of Terrestrial Land Plants

We are investigating how atmospheric carbon dioxide (CO2) concentrations impact the carbon isotope composition of C3 and C4 terrestrial land plants.

B.A. Schubert and A.H. Jahren. 2018 (Invited Review). Incorporating the effects of photorespiration into terrestrial paleoclimate reconstruction. Earth-Science Reviews, 177: 637-642. (view/download pdf)

W.M. Hagopian%, B.A. Schubert, R.A. Graper* and A.H. Jahren. 2018. Plant growth chamber design for subambient pCO2 and δ13C studies. Rapid Communications in Mass Spectrometry, DOI: 10.1002/rcm.8176. (view/download pdf)

B.A. Schubert and A.H. Jahren. 2015. Global increase in plant carbon isotope fractionation following the last glacial maximum caused by increase in atmospheric pCO2. Geology, DOI: 10.1130/G36467.1. (view/download pdf)

W.M. Hagopian%, B.A. Schubert and A.H. Jahren. 2015. Large-scale plant growth chamber design for elevated pCO2 and δ13C studies. Rapid Communications in Mass Spectrometry, 29(5): 440-446. (view/download pdf)

N.C. Arens, A.H. Jahren and D.C. Kendrick. 2014. Carbon isotope stratigraphy and correlation of plant megafossil localities in the Hell Creek Formation of eastern Montana, USA. Geological Society of America Special Papers, 503: 149-171. Geological Society of America Special Papers, 503: 149-171. (view/download pdf)

N.C. Arens, A. Thompson and A.H. Jahren. 2014. A preliminary test of the press-pulse extinction hypothesis: Palynological indicators of vegetation change preceding the Cretaceous-Paleogene boundary, McCone County, Montana, USA. Geological Society of America Special Papers, 503: 209-227. (view/download pdf)

B.A. Schubert% and A.H. Jahren. 2012. The effect of atmospheric CO2 concentration on carbon isotope fractionation in C3 land plants. Geochimica et Cosmochimica Acta, 96: 29-43. (view/download pdf).

D.C. King*, B.A. Schubert% and A.H. Jahren. 2012. Practical considerations for the use of pollen δ13C value as a paleoclimate indicator. Rapid Communications in Mass Spectrometry, (accepted and in-press). (view/download pdf).

B.A. Schubert%, A.H. Jahren. 2011. Quantifying seasonal precipitation using high-resolution carbon isotope analyses in evergreen wood. Geochimica et Cosmochimica Acta, 75(22): 7291-7303. (view/download pdf)

B.A. Schubert% and A.H. Jahren. 2011. Fertilization trajectory of the root crop Raphanus sativus across atmospheric pCO2 estimates of the next 300 years. Agriculture, Ecosystems, and Environment, 140(1-2) 174-181, doi: 10.1016/j.agee.2010.11.024. (view/download pdf)

A.H. Jahren and N.C. Arens. 2009. Prediction of atmospheric δ13CO2 using plant cuticle isolated from fluvial sediment: tests across a gradient in salt content.Palaios, 24, 394-401. doi: 10.2110/palo.2008.p08-069r. (view/download pdf)

A.H. Jahren, N.C. Arens and S.A. Harbeson*. 2008 (Invited). Prediction of atmospheric δ13CO2 using fossil plant tissues. Reviews of Geophysics, 46/2006RG0002. (view/download pdf target="_blank")

N.C. Arens, A.H. Jahren and R. Amundson. 2000. Can C3 plants faithfully record the carbon isotopic composition of atmospheric carbon dioxide? Paleobiology, 26(1), 137-164. (view/download pdf)

Back to top

The Carbon Isotope Composition of Ancient Terrestrial Organic Matter

We are investigating how the carbon isotope composition of fossil land plants and fossil organic matter can be used to infer climate change in ancient ecosystems.

M.T. Rabanus-Wallace, M.J. Wooller, G.D. Zazula, E. Shute, A.H. Jahren, P. Kosintsev, J.A. Burns, J. Breen, B. Llamas and A. Cooper. 2017. Megafaunal isotopes reveal role of increased moisture on rangeland during Late Pleistocene extinctions. Nature Ecology & Evolution, 1, 0125, DOI: 10.1038/s41559-017-0215. (view/download pdf)

B.A. Schubert% and A.H. Jahren. 2013. Reconciliation of marine and terrestrial carbon isotope excursions based on changing atmospheric CO2 levels. Nature Communications, 4:1653, DOI: 10.1038/ncomms2659. (view/download pdf)

A.H. Jahren, B.A. Schubert%, L. Marynowski and J.P. Wilson*. The carbon isotope organic geochemistry of Early Ordovician rocks from the Annascaul Formation, County Kerry. Irish Journal of Earth Sciences, 31: 1-12; doi: 10.3318/IJES.2013.31. (view/download pdf).

G.J. Retallack and A.H. Jahren. 2008. Methane release from igneous intrusion of coal during Late Permian extinction events. Journal of Geology, 116, 1-20. (view/download pdf)

G.J. Retallack, T.L. Greaver# and A.H. Jahren. 2007. Return to Coalsack Bluff and the Permian-Triassic boundary in Antarctica. Global and Planetary Change, 55, 90-108. (view/download pdf)

G.J. Retallack, C.A. Metzger*, T.L. Greaver#, A.H. Jahren, R.M.H. Smith and N.D. Sheldon. 2006. Middle-Late Permian mass extinction on land. GSA Bulletin, 118(11), 1398-1411. (view/download pdf)

A.H. Jahren, C.P. Conrad, N.C. Arens, G. Mora# and C. Lithgow-Bertelloni. 2005. A plate tectonic mechanism for methane hydrate release along subduction zones. Earth and Planetary Science Letters, 236, 691-704. (view/download pdf)

G.J. Retallack, A.H. Jahren, N.D. Sheldon*, R. Chakrabarti, C.A. Metzger and R.M.H. Smith. 2005. The Permian-Triassic boundary in Antarctica. Antarctic Science, 17(2), 241-258. (view/download pdf)

A.H. Jahren. 2002. The biogeochemical consequences of the mid-Cretaceous superplume. Journal of Geodynamics, 34, 177-191. (view/download pdf)

N.C. Arens and A.H. Jahren. 2002. Chemostratigraphic correlation of four fossil-bearing sections in southwestern North Dakota. in Hartman, J.H., Johnson, K.R., and Nichols, D.J. eds., The Hell Creek Formation and the Cretaceous-Tertiary boundary in the northern Great Plains: An integrated record of the end of the Cretaceous: Boulder, Colorado, Geological Society of America Special Paper, 361, 75-93. (view/download pdf)

A.H. Jahren, N.C. Arens, G. Sarmiento, J. Guerrero and R. Amundson. 2001. Terrestrial record of methane hydrate dissociation in the Early Cretaceous. Geology, 29(2), 159-162. (view/download pdf)

N.C. Arens and A.H. Jahren. 2000. Carbon isotopic excursion in atmospheric CO2 at the Cretaceous-Tertiary boundary: Evidence from terrestrial sediments. Palaios, 15(4), 314-322. (view/download pdf)

Back to top

The Arctic Eocene and Miocene

Millions of years ago, Arctic regions were home to forests containing diverse plant and animal species.  We are looking at the stable isotope composition of a variety of fossil substrates to reconstruct basic climate parameters as well as to gain insight into the ecology of the organisms living there.

B.A. Schubert, A.H. Jahren, S.P. Davydov and S. Warny. 2017. The transitional climate of the late Miocene Arctic: Winter-dominated precipitation with high seasonal variability. Geology, DOI: 10.1130/G38746.1. (view/download pdf)

B.A. Schubert%, A.H. Jahren, J.J. Eberle, L.S.L. Sternberg, and D.A. Eberth. 2012. A summertime rainy season in the Arctic forests of the Eocene. Geology, 40(6): 523–526, doi: 10.1130/G32856.1. (view/download pdf).

A.H. Jahren, M.C. Byrne*, H.V. Graham*, R.A. Summons and L.S.L. Sternberg. 2009. The environmental water of the Middle Eocene Arctic: Evidence from δD and δ18O within specific compounds.  Palaeogeography, Palaeoclimatology, Palaeoecology, 271(1-2), 96-103. doi: 10.1016/j.palaeo.2008.09.016. (view/download pdf)

A.H. Jahren and L.S.L. Sternberg. 2008. Annual patterns within tree rings of the Arctic middle Eocene (~45 Ma): Isotopic signatures of precipitation, relative humidity and deciduousness. Geology, 36(2), 99-102. (view/download pdf)

A.H. Jahren. 2007 (Invited). The Arctic forest of the middle Eocene. Annual Review of Earth and Planetary Sciences, 35, 509-540. (view/download pdf)

A.H. Jahren and L.S.L. Sternberg. 2003. Humidity estimate for the middle Eocene Arctic rain forest. Geology, 31(5), 463-466. (view/download pdf)

A.H. Jahren and L.S.L. Sternberg. 2002. Eocene meridional weather patterns reflected in the oxygen isotopes of Arctic fossil wood. GSA Today, 12(1), 4-9. (view/download pdf)

Back to top

Water and Isotopes in Plant Tissues

We are working with colleagues to pursue the isotope biophysiology of water in plants, particularly for the interpretation of cellulose and its derivatives.

B.A. Schubert and A.H. Jahren. 2015. Seasonal temperature and precipitation recorded in the intra-annual oxygen isotope pattern of meteoric water and tree-ring cellulose. Quaternary Science Reviews, 125: 1-14. (view/download pdf)

L.S.L. Sternberg, M.C. Pinzon, P.F. Vendramini, W.T. Anderson, A.H. Jahren and K. Beuning. 2007. Oxygen isotope ratios of cellulose derived phenylglucosazone: An improved paleoclimate indicator of environmental water and relative humidity. Geochimica et Cosmochimica Acta, 71, 2463-2473. (view/download pdf)

L.S.L. Sternberg, M.C. Pinzon, W.T. Anderson and A.H. Jahren. 2006. Variation in oxygen isotope fractionation during cellulose synthesis: molecular and biosynthetic effects. Plant, Cell and Environment, 29, 1881-1889. (view/download pdf)

G. Mora# and A.H. Jahren. 2003. Isotopic evidence for the role of plant development on transpiration in deciduous forests of the southern United States. Global Biogeochemical Cycles, 17(2), 2002GB001981. (view/download pdf)

Back to top

Isotopes and Human Diet

We have started new work investigating the link between stable isotopes in human blood and in human diet.

S.V. Liu, L.B. Moore, T.M. Halliday, A.H. Jahren, J. Salva, V.E. Hendrick, E.L. Marinik and B.M. Davy. 2018. Short-term changes in added sugar consumption by adolescents reflected in the carbon isotope ratio of fingerstick blood. Nutrition and Health, 24(4):251-253. (view/download pdf)

C.R. MacDougall, C.E. Hill, A.H. Jahren, J. Savla, S.K. Riebl, V.E. Hedrick, H.A. Raynor, J.C. Dunsmore, M.I. Frisard, and . B.M. Davy. 2018 The (δ13C) value of finger stick blood is a valid, reliable, and sensitive biomarker of sugar-sweetened beverage intake in children and adolescents. The Journal of Nutrition, 148(1): 147-152. (view/download pdf)

J.N. Bostic*, W.M. Hagopian%, and A.H. Jahren. 2018. Carbon and nitrogen stable isotopes in U.S. milk: Insight into production process. Rapid Communications in Mass Spectrometry, 32(7): 561-566. (view/download pdf)

B.M. Davy and A.H. Jahren. 2016 (Invited Review). New markers of dietary added sugar intake. Current Opinion in Clinical Nutrition and Metabolic Care, 19(4): 282-288. (view/download pdf)

B.M. Davy, A.H. Jahren, V.E. Hedrick, W. You and J.M. Zoellner. 2016. Influence of an intervention targeting a reduction in sugary beverage intake on the δ13C sugar intake biomarker in a predominantly obese, health-disparate sample. Public Health Nutrition, DOI:

V.E. Hedrick, B.M. Davy, G.A. Wilburn, A.H. Jahren and J.M. Zoellner. 2016. Evaluation of a novel biomarker of added sugar intake (δ13C) compared with self-reported added sugar intake and the Healthy Eating Index-2010 in a community-based, rural US sample. Public Health Nutrition, 19(3): 429-436. DOI: 10.1017/S136898001500107X. (view/download pdf)

V.E. Hedrick, J.M. Zoeller, A.H. Jahren, J.N. Bostic% and B.M. Davy. 2015. A dual-carbon-and-nitrogen stable isotope ratio model is not superior to a single-carbon stable isotope ratio model for predicting added sugar intake in Southwest Virginian adults. The Journal of Nutrition, DOI: 10.3945/jn.115.211011. (view/download pdf)

J.N. Bostic%, S.J. Palafox*, M.E. Rottmueller* and A.H. Jahren. 2015. Effect of baking and fermentation on the stable carbon and nitrogen isotope ratios of grain-based food. Rapid Communications in Mass Spectrometry, 29(10): 937-947. (view/download pdf)

A.H. Jahren, J.N. Bostic% and B.A. Davy. 2014 (Invited Review). The potential for a carbon stable isotope biomarker of dietary sugar intake. Journal of Analytical Atomic Spectrometry, 29(5): 795-816. DOI: 10.1039/C3JA50339A.(view/download pdf)

T.H.I. Fakhouri, A.H. Jahren, L.J. Appel, L. Chen, R. Alavi and C.A.M. Anderson. 2014. Change in serum carbon isotopes in response to change in sugar-sweetened beverage intake. Journal of Nutrition, 144(6): 902-905.(view/download pdf)

R.J. Panetta#, A.H. Jahren. 2011. Single-step transesterification with simultaneous concentration and stable isotope analysis of fatty acid methyl esters by gas chromatography-combustion-isotope ratio mass spectrometry.Rapid Communications in Mass Spectrometry, 25(10) 1372-1381. (view/download pdf)

B.M. Davy, A.H. Jahren, V.E. Hendrick*, D.L. Comber*. 2011. Association of δ13C in fingerstick blood with added-sugar and sugar-sweetened beverage Intake. Journal of the American Dietetic Association, 111(6) 874-878. (view/download pdf)

E.H. Yeung#, C.D. Saudek, A.H. Jahren, W.M.L. Kao, M. Islas*, R. Kraft*, J. Coresh, and C.A. Anderson. 2010. Evaluation of a novel isotope biomarker for dietary consuption of sweets. American Journal of Epidemiology; doi: 10.1093/aje/kwq247. (view/download pdf)

A.H. Jahren, and Schubert, BA#. 2010. The corn content of French-fry oil from national chain vs. small business restaurants, Proceedings of the National Academy of Sciences USA, 107(5) 2099-2101. (view/download pdf)

A.H. Jahren, R.A. Kraft*. 2008. Carbon and nitrogen stable isotopes in fastfood: Signatures of corn and confinement. Proceedings of the NationalAcademy of Sciences, 105(46), 17855-17860. doi: 10.1073 pnas.0809870105. (view/download pdf)

R.A. Kraft*, A.H. Jahren and C.D. Saudek. 2008. Clinical-scale investigation of stable isotopes in human blood: δ13C and δ15N from 406 patients at the Johns Hopkins Medical Institutions. Rapid Communications in Mass Spectrometry, 22(22), 3683-369. (view/download pdf)

A.H. Jahren, C. Saudek, E. Yeung*, W.H. Kao, R. Kraft* and B. Caballero. 2006. An isotopic method for quantifying sweeteners derived from corn and sugar cane.  American Journal of Clinical Nutrition, 84, 1380-1384. (view/download pdf)

Back to top

Forensic Applications of Stable Isotopes

We have researched new ways to gain the oxygen isotope signature from organic substrates containing nitrogen, such as IED explosives.

W.M. Hagopian%, and A.H. Jahren. 2012. Elimination of nitrogen interference during online oxygen isotope analysis of nitrogen-doped organics using the “NiCat” nickel reduction system. Rapid Communications in Mass Spectrometry, 26: 1776-1782 (view/download pdf).

G.B. Hunsinger#, W.M. Hagopian%, A.H. Jahren. 2010. Offline Oxygen Isotope Analysis of Organic Compounds with High N:O, Rapid Communications in Mass Spectrometry, 24, 3182-3186. (view/download pdf)

W.M. Hagopian%, and A.H. Jahren. 2010. Minimization of Sample Requirements for δ18O in Benzoic Acid, Rapid Communications in Mass Spectrometry, v. 24, p. 2542-2546; doi 10.1002/rcm.4669. (view/download pdf)

Back to top