, Volume 95, Issue 1, pp 61–76 | Cite as

A comparison of water and carbon dioxide exchange at a windy alpine tundra and subalpine forest site near Niwot Ridge, Colorado

  • Peter D. Blanken
  • Mark W. Williams
  • Sean P. Burns
  • Russell K. Monson
  • John Knowles
  • Kurt Chowanski
  • Todd Ackerman


Eddy covariance measurements of the surface energy balance and carbon dioxide exchange above high-elevation (3,480 m above sea level) alpine tundra located near Niwot Ridge, Colorado, were compared to simultaneous measurements made over an adjacent subalpine forest over two summers and one winter, from June 9, 2007 to July 3, 2008. The surface energy balance closure at the alpine site averaged 71 and 91%, winter and summer, respectively, due to the high wind speeds, short turbulent flux footprint, and relatively flat ridge-top location of the measurement site. Throughout the year, the alpine site was cooler with higher relative humidity, and had a higher horizontal wind speed, especially in winter, compared to the forest site. Wind direction was persistently downslope at the alpine site (summer and winter, day and night), whereas upslope winds were common at the forest site during summer daytime periods. The latent and sensible heat fluxes were consistently larger in magnitude at the forest site, with the largest differences during summer. The horizontal advective flux of CO2 at the alpine site averaged 6% of the net ecosystem exchange (NEE) during summer nights (5% during summer daytime), and was small in relation to the high wind speeds, relatively flat site, and weak sources of CO2 upwind of the site. The magnitudes and diurnal behavior of the alpine NEE calculated using three methods; eddy-covariance, friction velocity filter, and with advection and storage calculations, gave similar results. The period of net CO2 uptake (negative NEE) was 100 days at the alpine site with a net uptake of 16 g C m−2, compared to 208 days at the forest site with a net uptake of 108 g C m−2, with initiation of net uptake coinciding with air temperatures reaching +10°C. Winter respiration loss at the alpine site was 164 g C m−2 over 271 days, compared to 52 g C m−2 over 175 days at the forest site, with the initiation of net loss coinciding with air temperatures reaching −10°C at each site.


Alpine Carbon Eddy correlation Evaporation Niwot Ridge Water 


  1. Aubinet M, Grelle A, Ibrom A, Rannick U, Moncrief J, Foken T, Kowalski AS, Martin PH, Berbigier P, Bernhofer C, Clement R, Elbers J, Granier A, Grunwald T, Morgenstern K, Pilegaard K, Rebmann C, Snijders W, Valentini R, Vesala T (2000) Estimates of the annual net carbon and water exchange of forests: the EUROFLX methodology. Adv Ecol Res 30:113–175. doi:10.1016/S0065-2504(08)60018-5 CrossRefGoogle Scholar
  2. Aubinet M, Heinesch B, Yernaux M (2003) Horizontal and vertical CO2 advection in a sloping forest. Bound Lay Meteorol 108:397–417. doi:10.1023/A:1024168428135 CrossRefGoogle Scholar
  3. Baker WL, Veblen TT, Sherriff RL (2007) Fire, fuels and restoration of ponderosa pine-Douglas fir forests in the Rocky Mountains, USA. J Biogeogr 34:251–269. doi:10.1111/j.1365-2699.2006.01592.x CrossRefGoogle Scholar
  4. Barry RG (2008) Mountain weather and climate, 3rd edn. Cambridge University Press, Cambridge 506 ppGoogle Scholar
  5. Beniston M, Diaz HF, Bradley RS (1997) Climatic change at high elevation sites: an overview. Clim Change 36:233–251. doi:10.1023/A:1005380714349 CrossRefGoogle Scholar
  6. Bowling DR, Massman WJ, Schaeffer SM, Burns SP, Monson RK, William MW (2009) Biological and physical influences on the carbon isotope content of CO2 in a subalpine forest snowpack, Niwot Ridge, Colorado. Biogeochemistry (this issue). doi:10.1007/s10533-008-9233-4
  7. Burba GG, McDermitt DK, Grelle A, Anderson DJ, Xu L (2008) Addressing the influence of instrument surface heat exchange on the measurements of CO2 flux from open-path gas analyzers. Glob Chang Biol 14(8):1854–1876. doi:10.1111/j.1365-2486.2008.01606.x CrossRefGoogle Scholar
  8. Cline DW (1997) Snow surface energy exchanges and snowmelt at a continental midlatitude Alpine site. Water Resour Res 33(4):689–701. doi:10.1029/97WR00026 CrossRefGoogle Scholar
  9. Daly C, Shankman D (1985) Seedling establishment by conifers above tree limit on Niwot Ridge, Front Rage, Colorado, USA. Arct Alp Res 17:389–400. doi:10.2307/1550864 CrossRefGoogle Scholar
  10. Elliot GP, Baker WL (2004) Quaking aspen (populus tremuloides Michx.) at tree line: a century of change in the San Juan Mountains, Colorado, USA. J Biogeogr 31:733–745Google Scholar
  11. Feigenwinter C, Bernhofer C, Vogt R (2004) The influence of advection on the short term CO2 budget in and above a forest canopy. Bound Lay Meteorol 113:201–224. doi:10.1023/B:BOUN.0000039372.86053.ff CrossRefGoogle Scholar
  12. Feigenwinter C et al (2008) Comparison of horizontal and vertical advective CO2 fluxes at three forest sites. Agric For Meteorol 148:12–24. doi:10.1016/j.agrformet.2007.08.013 CrossRefGoogle Scholar
  13. Gehrig-Fasel J, Guisan A, Zimmermann NE (2007) Tree line shifts in the swiss alps: climate change or land abandonment? J Veg Sci 18:571–582Google Scholar
  14. Goulden ML, Munger JW, Fan S-M, Daube BC, Wofsy SC (1996) Measurements of carbon sequestration by long-term eddy covariance: methods and critical evaluation of accuracy. Glob Chang Biol 2:169–182. doi:10.1111/j.1365-2486.1996.tb00070.x CrossRefGoogle Scholar
  15. Gu S, Tang YH, Cui XY, Du M, Zhao L, Li Y, Xu SX, Zhou H, Kato T, Qi PT, Zhao X (2008) Characterizing evapotranspiration over a meadow ecosystem on the Qinghai-Tibetan Plateau. J Geophys Res–Atmos, 113: D08118, doi:10.1029/2007JD009173
  16. Hammerle A, Haslwanter A, Schmitt M, Bahn M, Tappeiner U, Cernusca A, Wohlfahrt G (2007) Eddy covariance measurements of carbon dioxide, latent and sensible energy fluxes above a meadow on a mountain slope. Bound Lay Meteorol 122:397–416. doi:10.1007/s10546-006-9109-x CrossRefGoogle Scholar
  17. Humphries HC, Coffin DP, Laurenroth WK (1996) An individual-based model of alpine plant distributions. Ecol Modell 84:99–126. doi:10.1016/0304-3800(94)00144-8 CrossRefGoogle Scholar
  18. Jarlan L, Balsmo G, Lafont S, Beljaars A, Calvet JC, Mougin E (2008) Analysis of leaf area index in the ECMWF land surface model and impact on latent heat and carbon fluxes: application to West Africa. J Geophys Res-Atmos 113: Article D24117Google Scholar
  19. Keller F, Kienast F, Beniston M (2000) Evidence of response of vegetation to environmental change on high-elevation sites in the Swiss Alps. Reg Environ Change 1:70–77. doi:10.1007/PL00011535 CrossRefGoogle Scholar
  20. Kerwin MW, Overpeck JT, Webb RS, Anderson KH (2004) Pollen-based summer temperature reconstructions for the eastern Canadian boreal forest, subarctic, and Arctic. Quat Sci Rev 23:1901–1924. doi:10.1016/j.quascirev.2004.03.013 CrossRefGoogle Scholar
  21. Kittel T, Chowanski K, Ackerman T (2007) Long-term climate record. Niwot Ridge LTER NSF Report, June 2007Google Scholar
  22. Körner C (2003) Alpine plant life–functional plant ecology of high mountain ecosystems, 2nd edn. Springer, BerlinGoogle Scholar
  23. Kutsch W, Kolle O, Rebmann C, Knohl A, Ziegler W, Schulze E-D (2008) Advection and resulting CO2 exchange uncertainty in a tall forest in central Germany. Ecol Appl 18(6):1391–1405. doi:10.1890/06-1301.1 CrossRefGoogle Scholar
  24. Lee X, Massman W, Law B (2004) Handbook of micrometeorology: a guide for surface flux measurements and analysis. Kluwer Academic Publishers, Dordrecht 250 ppGoogle Scholar
  25. Leuning R, Zegelin SJ, Jones K, Keith H, Hughes D (2008) Measurement of horizontal and vertical advection of CO2 within a forest canopy. Agric For Meteorol 148:1777–1797. doi:10.1016/j.agrformet.2008.06.006 CrossRefGoogle Scholar
  26. Lewicki JL, Fisher ML, Hilley GE (2008) Six-week time series of eddy covariance CO2 flux at Mammoth Mountain, California: performance evaluation and role of meteorological forcing. J Volcanol Geotherm Res 171:178–190. doi:10.1016/j.jvolgeores.2007.11.029 CrossRefGoogle Scholar
  27. MacDonald GM, Edwards TWD, Moser DA, Pienitz R, Smol JP (1993) Rapid response of tree line vegetation and lakes to past climate warming. Nature 361:243–246. doi:10.1038/361243a0 CrossRefGoogle Scholar
  28. McMillen RT (1988) An eddy correlation technique with extended applicability to non-simple terrain. Bound Lay Meteorol 43:231–245. doi:10.1007/BF00128405 CrossRefGoogle Scholar
  29. Molotch NP, Blanken PD, Williams M, Turnipseed A, Monson R, Margulis S (2007) Estimating sublimation of intercepted and sub-canopy snow using eddy covariance systems. Hydrol Process 21(12):1567–1575. doi:10.1002/hyp.6719 CrossRefGoogle Scholar
  30. Monson RK, Turnipseed AA, Sparks JP, Harley PC, Scott-Denton LE, Sparks K, Huxman TE (2002) Carbon sequestration in a high-elevation subalpine forests. Glob Chang Biol 8:459–478. doi:10.1046/j.1365-2486.2002.00480.x CrossRefGoogle Scholar
  31. Monson RK, Lipson DL, Burns SP, Turnipseed AA, Delany AC, Williams MW, Schmidt SK (2006) Winter forest soil respiration controlled by climate and microbial community composition. Nature 439:711–714. doi:10.1038/nature04555 CrossRefGoogle Scholar
  32. Motta R, Nola P (2001) Growth trends and dynamics in subalpine forest stand in the Varaita Valley (Piedmont, Italy) and their relationships with human activities and global change. J Veg Sci 12:219–230. doi:10.2307/3236606 CrossRefGoogle Scholar
  33. Negron JF, Popp JB (2004) Probability of ponderosa pine infestation by mountain pine beetle in the Colorado Front Range. For Ecol Manage 191:17–27. doi:10.1016/j.foreco.2003.10.026 CrossRefGoogle Scholar
  34. Pauli H, Gottfried M, Grabherr G (2001) High summits of the Alps in a changing climate. The oldest observation series on high mountain plant diversity in Europe. In: Walther GR, Burga CA, Edwards PJ (eds) Fingerprints of climate change. Adapted behaviour and shifting species ranges. Kluwer Academic/Plenum Publishers, New York, pp 139–149Google Scholar
  35. Paulsen J, Weber UM, Körner C (2000) Tree growth near tree line: abrupt or gradual reduction with altitude? Arct Antarct Alp Res 32:14–20. doi:10.2307/1552405 CrossRefGoogle Scholar
  36. Schuepp PH, Leclerc MY, MacPherson JI, Desjardins RL (1990) Footprint prediction of scalar fluxes from analytical solutions of the diffusion equation. Bound Lay Meteorol 50:353–373CrossRefGoogle Scholar
  37. Seastedt T, Bowman B, Caine N, McKnight D, Townsend A, Williams MW (2004) The landscape continuum: a conceptual model for high elevation ecosystems. BioScience 54(2):111–121CrossRefGoogle Scholar
  38. Sherriff RL, Veblen TT, Sibold JS (2001) Fire history in high elevation subalpine forests in the Colorado Front Range. Ecosicence 8:369–380Google Scholar
  39. Shi X, Xu LL, HE YT, Zhang XZ, Zhang DQ, Yu GR (2006) Net ecosystem CO2 exchange and controlling factors in a steppe-Kobresia meadow on the Tibetan Plateau. Sci China Ser D- Earth Sci 49:207–218CrossRefGoogle Scholar
  40. Sievering H, Tomaszewski T, Torizzo J (2007) Canopy uptake of atmospheric N deposition at a conifer forest: Part 1-Canopy N budget, photosynthetic efficiency and net ecosystem exchange. Tellus Ser B 59:483–492. doi:10.1111/j.1600-0889.2007.00264.x CrossRefGoogle Scholar
  41. Staebler RM, Fitzjarrald DR (2004) Observing subcanopy CO2 advection. Agric For Meteorol 122:139–156. doi:10.1016/j.agrformet.2003.09.011 CrossRefGoogle Scholar
  42. Sun J, Mahrt L (1994) Spatial-distribution of surface fluxes estimated from remotely sensed variables. J Appl Meteorol 33(11):1341–1353. doi:10.1175/1520-0450(1994)033<1341:SDOSFE>2.0.CO;2 CrossRefGoogle Scholar
  43. Sun J, Burns SP, Delany AC, Oncley SP, Turnipseed AA, Stephns BB, Lenschow DH, LeMone MA, Monson RK, Anderson DE (2007) CO2 transport over complex terrain. Agric For Meteorol 145:1–21. doi:10.1016/j.agrformet.2007.02.007 CrossRefGoogle Scholar
  44. Turnipseed AA, Blanken PD, Anderson DE, Monson RK (2002) Energy budget above a high-elevation subalpine forest in complex terrain. Agric For Meteorol 110:177–201. doi:10.1016/S0168-1923(01)00290-8 CrossRefGoogle Scholar
  45. Turnipseed AA, Anderson DE, Burns S, Blanken PD, Baugh WM, Monson RK (2003) Airflows and turbulent flux measurements in mountainous terrain, Part I. Canopy and local effects. Agric For Meteorol 119:1–21. doi:10.1016/S0168-1923(03)00136-9 CrossRefGoogle Scholar
  46. Turnipseed AA, Anderson DE, Burns S, Blanken PD, Monson RK (2004) Airflows and turbulent flux measurements in mountainous terrain, Part II. Mesoscale effects. Agric For Meteorol 125:187–205. doi:10.1016/j.agrformet.2004.04.007 CrossRefGoogle Scholar
  47. Walker MD, Walker DA, Theodose TA, Webber PJ (2001) The vegetation: hierarchical species-environment relationships. In: Bowman WD, Seastedt TR (eds) Structure and function of an alpine ecosystem: Niwot Ridge, Colorado. Oxford University Press, New YorkGoogle Scholar
  48. Walther G-R, Beissner S, Burga CA (2005) Trends in the upward shift of alpine plants. J Veg Sci 16:541–548CrossRefGoogle Scholar
  49. Wang W, Davis KJ, Cook BD, Bakwin PS, Chuixiang Y, Butler MP, Ricciuto DM (2005) Surface layer CO2 budget and advective contributions to measurements of net ecosystem-atmosphere exchange of CO2. Agr For Meteorol 135:202–214CrossRefGoogle Scholar
  50. Wilczak JM, Oncley SP, Stage SA (2001) Sonic anemometer tilt correction algorithms. Bound Lay Meteorol 99:127–150CrossRefGoogle Scholar
  51. Williams MW, Losleben M, Hamann H (2002) Alpine areas in the colorado front range as monitors of climate change and ecosystem response. Geogr Rev 92:180–191CrossRefGoogle Scholar
  52. Yi C, Anderson DE, Turnipseed AA, Burns SP, Sparks JP, Stannard DI, Monson RK (2008) The contribution of advective fluxes to net ecosystem CO2 exchange in a high-elevation, subalpine forest. Ecol Appl 18:1379–1390CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Peter D. Blanken
    • 1
  • Mark W. Williams
    • 1
    • 2
  • Sean P. Burns
    • 3
    • 4
  • Russell K. Monson
    • 5
  • John Knowles
    • 1
    • 2
  • Kurt Chowanski
    • 2
  • Todd Ackerman
    • 2
  1. 1.Department of GeographyUniversity of Colorado at BoulderBoulderUSA
  2. 2.Institute of Arctic and Alpine ResearchUniversity of Colorado at BoulderBoulderUSA
  3. 3.Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderUSA
  4. 4.National Center for Atmospheric ResearchBoulderUSA
  5. 5.Department of Ecology and Evolutionary Biology and Cooperative Institute for Research in Environmental SciencesUniversity of ColoradoBoulderUSA

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