Andy Bunn



I'm an environmental scientist interested in climate and energy. Most of my research has to do with paleoclimate and carbon cycling. Reach out to me directly for more information about my lab, research, going to grad school etc. Many of my publications are available via my Google Scholar profile.  My code projects like dplR and xDateR are on GitHub. I was the founding director of the Institute for Energy Studies which seeks to give students a thorough education in energy across science, technology, and policy.

Most of my current research focuses on the dendroclimatology of Ancient Bristlecone Pine. There has been some nice press coverage of this work on CBS Sunday Morning and in the New Yorker.

I tweet occasionally at FakeAndyBunn.

I'm a musician as well. You can find my solo stuff on BandCamp and on Spotify, Apple Music, YouTubeI play guitar in the High Mountain String Band.



PhD Environmental Sciences, Montana State University-Bozeman; MEM Resource Ecology, Duke University; BS, The Evergreen State College

Research Interests

Carbon cycling



Updated sporadically. Many of these are available via my Google Scholar profile.


  1. Fordham E M, Pfeiffer A M, Bunn A G, Novak S J (2023) Recurrent debris flows and their downstream fate: Geomorphic drivers of an anomalous sediment load, Suiattle River, Washington State, USA. Earth Surface Processes and Landforms, 1-14. doi:10.1002/esp.5551

  2. Trinies C A, Bunn A G, Robertson C S, Anchukaitis K J (2022) Dendroclimatology of yellow-cedar (Callitropsis nootkatensis) and temperature variability on the western slopes of the North Cascades in Washington State, USA from 1333 to 2015 CE. Tree-Ring Research doi:10.3959/2021-20

  3. Riedel J L, Clague J, Bunn A G (2021) Reconstruction of climate and ecology of Skagit Valley, Washington, from 27.7 to 19.8 ka based on plant and beetle macrofossils. Quaternary Research, doi:10.1017/qua.2021.50 

  4. Kemp-Jennings S , Peterson D L, Bunn A G (2021) Temporal variability in climate-growth response of mountain hemlock at treeline in Washington and Oregon. Northwest Science, 94: 286-301, doi:10.3955/046.094.0306

  5. Tardif J C, Salzer M W, Conciatori F, Bunn A G, Hughes M K  (2020) Formation, structure and climatic significance of blue rings and frost rings in high elevation bristlecone pine (Pinus longaeva D.K. Bailey). Quaternary Science Reviews, doi:10.1016/j.quascirev.2020.106516

  6. Khider D, Emile-Geay J, McKay N, Gil Y, Garijo D, Ratnakar V, Alonso-Garcia M, Bertrand S, Bothe O, Brewer P, Bunn A, Chevalier M, Comas-Bru L, Csank A, Dassi\'{e} E, DeLong K, Felis T, Francus P, Frappier A, Gray W, Goring S, Jonkers L, Kahle M, Kaufman D, Kehrwald N, Martrat B, McGregor H, Richey J, Schmittner A, Scroxton N, Sutherland E, Thirumalai K, Allen K, Arnaud F, Axford Y, Barrows T T, Bazin L, Pilaar Birch S, Bradley E, Bregy J, Capron E, Cartapanis O, Chiang H, Cobb K, Debret M, Dommain R, Du J, Dyez K, Emerick S, Erb M, Falster G, Finsinger W, Fortier D, Gauthier N, George S, Grimm E, Hertzberg J, Hibbert F, Hillman A, Hobbs W, Huber M, Hughes A, Jaccard S, Ruan J, Kienast M, Konecky B, Le Roux G, Lyubchich V, Novello V, Olaka L, Partin J, Pearce C, Phipps S, Pignol C, Piotrowska N, Poli M, Prokopenko A, Schwanck F, Stepanek C, Swann G, Telford R, Thomas E, Thomas Z, Truebe S, Gunten L, Waite A, Weitzel N, Wilhelm B, Williams J, Williams J, Winstrup M, Zhao N, Zhou Y (2019), PaCTS 1.0: A Crowdsourced Reporting Standard for Paleoclimate Data. Paleoceanography and Paleoclimatology, 34: 1570-1596, doi:10.1029/2019PA003632

  7. Hughes, M K, Olchev A, Bunn A G, Berner L T, Losleben M, Novenko E (2019) Different climate responses of spruce and pine growth in northern European Russia. Dendrochronologia, doi:10.1016/j.dendro.2019.05.005

  8. Bunn A G, Salzer M W, Anchukaitis K J, Bruening J M, Hughes M K  (2018) Spatiotemporal variability in the climate growth response of high elevation bristlecone pine in the White Mountains of California. Geophysical Research Letters, doi:10.1029/2018GL080981

  9. Quinn T P,  Helfield J M, Austin C, Hovel R A,  Bunn A G (2018) A multi-decade experiment shows that fertilization by salmon carcasses enhanced tree growth in the riparian zone. Ecology, doi:10.1002/ecy.2453

  10. Bruening J M,  Bunn A G, Salzer M W (2018) A climate-driven treeline position model in the White Mountains of California over the past six millennia. Journal of Biogeography, doi:10.1111/jbi.13191

  11. Lloyd A H, Sullivan P, and Bunn A G (2017)  Upper and Latitudinal Treelines.  In Amoroso M, P Baker, J Camarero Martinez, L Daniels, Editors.  Dendroecology: Tree-ring analyses applied to ecological studies.  Springer-Verlag ISBN 978-3-319-61669-8.

  12. Webb E, Heard K, Natali S, Bunn A G,  Alexander H, Berner L, Kholodov A, Loranty M, Schade J, Spektor V, Zimov N (2017) Variability in above and belowground carbon stocks  in a Siberian Larch watershed. Biogeosciences, 10.5194/bg-14-4279-2017

  13. Bunn A G, Helfield J M, Gerdts J R, Gleaves D A, Drake D C, Sheppard P R (2017) Solvent-based extraction fails to remove mobile nitrogen from sapwood of western red cedar (Thuja plicata). Dendrochronologia, doi:10.1016/j.dendro.2017.03.001

  14. Bruening J M, Tran T J,  Bunn A G, Salzer M W, Weiss S B (2017) Fine-scale modeling of bristlecone pine treeline position in the Great Basin, USA. Environmental Research Letters, doi:10.1088/1748-9326/aa5432

  15. Tran T J, Bruening J M,  Bunn A G, Salzer M W, Weiss S B (2017) Cluster analysis and topoclimate modeling to examine bristlecone pine tree-ring growth signals in the Great Basin, USA. Environmental Research Letters, doi:10.1088/1748-9326/aa5388

  16. Salzer M.W., Larson E., Bunn A.G., Hughes M.K.  (2014) Climate response in near-treeline bristlecone pine. Environmental Research Letters, doi:10.1088/1748-9326/9/11/114007

  17. Berner, L., P Beck, A.G. Bunn, and S.J. Goetz. 2013. Plant growth and climate variability along the forest-tundra ecotone in northeastern Siberia. Global Change Biology. doi: 10.1111/gcb.12304.
  18. Bunn, A.G., Hughes, M.K., Kirdyanov, A.V., Losleben, M., Shishov, V.V., Berner L.T., Oltchev, A., and E.A. Vaganov. 2013. Comparing forest measurements from tree rings and a space-based index of vegetation activity in Siberia. Environmental Research Letters. doi:10.1088/1748-9326/8/3/035034.
  19. Bunn, A.G., Jansma, E., Korpela, M., and R.D. Westfall. 2013. Using simulations and data to evaluate mean sensitivity as a useful statistic in Dendrochronology. Dendrochronologia. doi:10.1016/j.dendro.2013.01.004.
  20. Salzer, M.W., Bunn, A.G., Graham, N.E., and M.K. Hughes. 2013. Five millennia of paleotemperature from tree-rings and treeline change in the Great Basin USA. Climate Dynamics. doi: 10.1007/s00382-013-1911-9.
  21. Forester, B., DeChaine, E., and A.G. Bunn. Integrating ensemble species distribution modeling and statistical phylogeography to inform projections of climate change impacts on species distributions. Diversity and Distributions. doi:10.1111/ddi.12098.
  22. Xu, L. Myneni, R.B., Chapin III, F.S., Callaghan, T.V., Pinzon, J.E., Tucker, C.J., Zhu Z., Bi, J., Ciais, P., Tømmervik, H., Euskirchen, E.S., Forbes, B.C., Piao, S.L., Anderson, B.T. Ganguly, Nemani, S., Goetz, S.J., Beck, P., Bunn, A.G., Cao, C., and J.C. Stroeve. 2013. Temperature and vegetation seasonality diminishment over northern lands. Nature Climate Change. doi:10.1038/nclimate1836.
  23. Bond-Lamberty, B., Bunn, A.G., and A.M. Thomson. 2012. Forest browning and large-scale lag effects drive recent trends in high-latitude soil respiration. PLoS ONE. doi:10.1371/journal.pone.0050441.
  24. Stephenson, N.L., van Mantgem, P.J., Bunn, A.G., Bruner, H., Harmon, M.E., O'Connell, K.B., Urban, D.L., Franklin, J.F. 2011. Causes and implications of the correlation between forest productivity and tree mortality rates. Ecological Monographs. doi:10.1890/10-1077.1
  25. Berner, L., Beck P., Bunn A.G., Lloyd A.H., and S.J. Goetz. 2011. High-latitude tree growth and satellite vegetation indices: Correlations and trends in Russia and Canada (1982-2008). Journal of Geophysical Research – Biogeosciences. doi:10.1029/2010JG001475
  26. Bunn, A.G., M.K. Hughes, and M.W. Salzer. 2011. Topographically modified tree-ring chronologies as a potential means to improve paleoclimate inference. Climatic Change. doi: 10.1007/s10584-010-0005-5.
  27. Pederson, G.T., Gray, S.T., Ault T.A., Marsh, W., Fagre D.B., Bunn, A.G., Woodhouse, C.A., Graumlich, L.J. 2011. Climatic controls on the snowmelt hydrology of the northern Rocky Mountains, USA. Journal of Climate. doi:10.1175/2010JCLI3729.1.
  28. Lloyd A.H., Bunn A.G., and L. Berner. 2011. A latitudinal gradient in tree growth response to climate warming in the Siberian taiga. Global Change Biology. doi:10.1111/j.1365-2486.2010.02360.x
  29. Goetz, S.J., Epstein, H.E., Alcaraz, D., Beck, P., Bhatt, U., Bunn, A.G., Comiso, J., Jia, G.J., Kaplan, J.O., Lischke, H., Lloyd, A.H., Yu, Q., Walker, D.A. 2011. Recent changes in arctic vegetation: satellite observations and simulation model predictions. In: Eurasian Arctic Land Cover and Land Use in a Changing Climate [Gutman, G; and Reissell, A. (Eds.)]. Springer ISBN: 978-90-481-9117-8.
  30. Bunn, A.G. 2010. Statistical and visual crossdating in R using the dplR library. Dendrochronologia 28: 251-258.
  31. Salzer, M.W., M.K. Hughes, A.G. Bunn, and K.F. Kipfmueller. 2009. Recent unprecedented tree-ring growth in bristlecone pine at the highest elevations and possible causes. Proceedings of the National Academy of Sciences. doi: 10.1073pnas.0903029106.
  32. Bunn, A.G. 2009. The rock and ice problem in national parks: an opportunity for monitoring climate change impacts. Park Science 26 17-21.
  33. Bunn, A.G. 2008. A dendrochronology program library in R (dplR). Dendrochronologia, 26: 115-124.
  34. Malanson, G.P., D.R. Butler, D.B. Fagre, S.J. Walsh, D.F. Tomback, L.D. Daniels, L.M. Resler, W.K. Smith, D.J. Weiss, D.L. Peterson, A.G. Bunn, C.A. Hiemstra, D. Liptzin, P.S. Bourgeron, Z. Shen, and C.I. Millar. 2007. Alpine treeline of western North America: Linking organism-to-landscape dynamics. Physical Geography 28, 378–396.
  35. Houghton, R.A., D. Butman, A.G. Bunn, O.N. Krankina, P. Schlesinger, T.A. Stone. 2007. Mapping Russian forest biomass with data from satellites and forest inventories. Environmental Research Letters 2, 045032 (7pp): doi:10.1088/1748-9326/2/4/045032.
  36. Lloyd, A.H. and A.G. Bunn. 2007. Responses of the circumpolar boreal forest to 20th century climate variability. Environmental Research Letters 2, 045013 (13pp): doi:10.1088/1748-9326/2/4/045013.
  37. Schrag, A.M., A.G. Bunn, and L.J. Graumlich. 2007. Influence of bioclimatic variables on treeline conifer distribution in the Greater Yellowstone Ecosystem: implications for species of special concern. Journal of Biogeography doi:10.1111/j.1365-2699.2007.01815.x.
  38. Bunn, A.G., S.J. Goetz, J.S. Kimball, and K. Zhang. 2007. Northern high latitude ecosystems respond to recent climate change. Eos 88:333-335.
  39. Bunn, A.G. and S.J. Goetz. 2006. Trends in satellite observed circumpolar photosynthetic activity from 1982-2003: The influence of seasonality, cover type and vegetation density. Earth Interactions 10:1-19.
  40. Goetz, S.J., G.J., Fiske, and A.G. Bunn. 2006. Using satellite time-series data sets to analyze fire disturbance and recovery in the Canadian boreal forest. Remote Sensing of Environment 101:352-365.
  41. Zambon, M., R.L. Lawrence, A.G. Bunn, and S. Powell. 2006. Effect of alternative splitting rules on image processing using classification tree analysis. Photogrammetic Engineering & Remote Sensing 72 (1): 25-30.
  42. Bunn, A.G., S.J. Goetz, and G.J. Fiske. 2005. Observed and predicted responses of plant growth to climate across Canada. Geophysical Research Letters 32:L16710.
  43. Goetz, S.J., A.G. Bunn, and G.J. Fiske. 2005. Satellite observed photosynthetic trends across boreal North America associated with climate and fire disturbance. Proceedings of the National Academy of Sciences 103(38): 13521-13525.
  44. Bunn, A.G., L.J. Graumlich, and D.L. Urban. 2005. Interpreting the climatic significance of trends in twentieth-century tree growth at high elevations. The Holocene 15(4): 481-488.
  45. Graumlich, L.G., Waggoner, L.A., and A.G. Bunn, 2005. Detecting change at alpine treeline: coupling paleoecology with contemporary studies. In Global Change and Mountain Regions: An Overview of Current Knowledge. Series: Advances in Global Change Research, Vol. 23 (ed. by U. Huber, H. Bugmann, and M. Reasoner), pp 405-412. Springer, Dordrecht, the Netherlands. ISBN: 1-4020-3506-3, 650 p.
  46. Bunn, A.G., L.A. Waggoner, and L.J. Graumlich. 2005. Topographic mediation of growth in high elevation foxtail pine (Pinus balfouriana Grev. et Balf.) forests in Sierra Nevada, USA. Global Ecology and Biogeography 14: 103-114.
  47. Bunn, A.G., T.J. Sharac, and L.J. Graumlich. 2004. Using a simulation model to compare methods of tree-ring detrending and to investigate the detectability of low-frequency signals. Journal of Tree-Ring Research 60(2): 77-90.
  48. Lawrence, R.L., A.G. Bunn, S. Powell, and M. Zambon. 2004. Classification of remotely sensed imagery using stochastic gradient boosting as a refinement of classification tree analysis. Remote Sensing of Environment 90:331-336.
  49. Bunn, A. G., R.L. Lawrence, G.J. Bellante, L.A. Waggoner, and L.J. Graumlich. 2003. Spatial variation in distribution and growth patterns of old growth strip-bark pines. Arctic, Antarctic and Alpine Research 35:323-330.
  50. Bunn A.G., D.L. Urban, and T. Keitt. 2000. Landscape connectivity: a conservation application of graph theory. Journal of Environmental Management 59: 265-278.
  51. Bunn A.G., W. Klien, and K.L. Bildstein. 1995. Time-of-day effects on the numbers and behavior of non-breeding raptors in Eastern Pennsylvania. Journal of Field Ornithology, 66(4): 544-552.