, Volume 92, Issue 4, pp 463–474 | Cite as

A generalized, lumped-parameter model of photosynthesis, evapotranspiration and net primary production in temperate and boreal forest ecosystems

  • John D. Aber
  • C. Anthony Federer
Original Papers


PnET is a simple, lumped-parameter, monthlytime-step model of carbon and water balances of forests built on two principal relationships: 1) maximum photosynthetic rate is a function of foliar nitrogen concentration, and 2) stomatal conductance is a function of realized photosynthetic rate. Monthyly leaf area display and carbon and water balances are predicted by combining these with standard equations describing light attenuation in canopies and photosynthetic response to diminishing radiation intensity, along with effects of soil water stress and vapor pressure deficit (VPD). PnET has been validated against field data from 10 well-studied temperate and boreal forest ecosystems, supporting our central hypothesis that aggregation of climatic data to the monthly scale and biological data such as foliar characteristics to the ecosystem level does not cause a significant loss of information relative to long-term, mean ecosystem responses. Sensitivity analyses reveal a diversity of responses among systems to identical alterations in climatic drivers. This suggests that great care should be used in developing generalizations as to how forests will respond to a changing climate. Also critical is the degree to which the temperature responses of photosynthesis and respiration might acclimate to changes in mean temperatures at decadal time scales. An extreme climate change simulation (+3° C maximum temperature, −25% precipitation with no change in minimum temperature or radiation, direct effects of increased atmospheric CO2 ignored) suggests that major increases in water stress, and reductions in biomass production (net carbon gain) and water yield would follow such a change.

Key words

Conductance Foliar nitrogen Water balance LAI 


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  1. Aber JD, Magill A, Boone R, Melillo JM, Steudler P, Bowden R (1992) Plant and soil responses to three years of chronic nitrogen additions at the Harvard Forest, Petersham, MA. Ecol Appl (in press)Google Scholar
  2. Aber JD, Melillo JM, Nadelhoffer KJ, McClaugherty CA, Pastor J (1985) Fine root turnover in forest ecosystems in relation to the quantity and form of nitrogen availability: A comparison of two methods. Oecologia 66: 317–321Google Scholar
  3. Abrams MD, Schultz JC, Kleiner KW (1990) Ecophysiological responses in mesic versus xeric hardwood species to an carly-season drought in central Pennsylvania. Forest Science 36: 970–981Google Scholar
  4. Agren GI, Bosatta E (1988) Nitrogen saturation of terrestrial ecosystems. Environ Poll 54: 185–197Google Scholar
  5. Amthor JS, Gill DS, Bormann FH (1990) Autumnal leaf conductance and apparent photosynthesis by saplings and sprouts in a recently disturbed northern hardwood forest. Oecologia 84: 93–98Google Scholar
  6. Aubuchon RR, Thompson DR, Hinckley TM (1978) Environmental influences on photosynthesis within a crown of white oak. Oecologia 35: 295–306Google Scholar
  7. Bahari ZA, Pallardy SG, Parker WC (1985) Photosynthesis, water relations and drought adaptation in six woody species of oakhickory forests in central Missouri. Forest Science 31: 557–569Google Scholar
  8. Baldocchi DD, Luxmore RJ, Hatfield JL (1991) Discerning the forest from the trees: an essay on scaling canopy stomatal conductance. Agric For Meteorol 54: 197–226Google Scholar
  9. Baldocchi DD, Verma SB, Anderson DE (1987) Canopy photosynthesis and water-use efficiency in a deciduous forest. J Appl Ecol 24: 251–260Google Scholar
  10. Bazzaz FA (1990) The response of natural ecosystems to the rising global CO2 levels. Annual Rev Ecol System 21: 167–196Google Scholar
  11. Bazzaz FA, Fajer, ED (1992) Plant Life in a CO2-rich world. Sci Am 266: 68–74Google Scholar
  12. Bierhuizen JF, Slatyer RO (1965) Effect of atmospheric concentration of water vapor and CO2 in determining transpiration-photosynthesis relationships of cotton leaves. Agricul Meteorol 2: 259–270Google Scholar
  13. Botkin DB, Janak JF, Wallis JR (1972) Some ecological consequences of a computer model of forest growth. J Ecol 60: 849–872Google Scholar
  14. Brix H (1972) Nitrogen fertilization and water effects on photosynthesis and earlywood-latewood production in Douglas-fir. Can J For Res 2: 467–478Google Scholar
  15. Cosby BJ, Hornberger GM, Galloway JN (1985) Modeling the effects of acid deposition: assessment of a lumped parameter model of soil and streamwater chemistry. Water Res Res 21: 51–63Google Scholar
  16. Dickinson RE, Henderson-Sellers A, Rosenzweig C, Sellers PJ (1991) Evapotranspiration models with canopy resistance for use in climatic models, a review. Agricul Forest Meteor 54: 373–388Google Scholar
  17. Fahey TJ, Knight DH (1986) Lodgepole pine ecosystems. Bio-Science 36: 610–617Google Scholar
  18. Fahey TJ, Yavitt JB, Pearson JA, Knight DH (1985) The nitrogen cycle in lodgepole pine forests, southeastern Wyoming. Biogeochemistry 1: 257–276Google Scholar
  19. Fahey TJ, Young DR (1984) Soil and xylem water potential and soil water content in contrasting Pinus contorta ecosystems, southeastern Wyoming, USA. Oecologia 61: 346–351Google Scholar
  20. Federer CA, Flynn LD, Martin CW, Hornbeck JW, Pierce RS (1990) Thirty years of hydrometeorologic data at the Hubbard Brook Experimental Forest, New Hampshire USDA U.S. Forest Ser Gen Tech Report NE-141Google Scholar
  21. Federer CA, Lash D (1978a) BROOK: A hydrologic simulation model for eastern forests. Univ. New Hamp. Water Resource Res Cent Rept 19Google Scholar
  22. Federer CA, Lash D (1978b) Simulated streamflow response to possible differences in transpiration among species of hardwood trees. Water Res Res 14: 1089–1097Google Scholar
  23. Field CJ, Mooney HA (1986) The photosynthesis-nitrogen relationship in wild plants. In: Givinish TJ (ed) On the Economy of Plant Form and Function. Cambridge University Press, New York, pp 25–55Google Scholar
  24. Fownes JH (1985) Water use and primary production of Wisconsin hardwood forests. Dissertation, Univ. of Wisconsin, Madison, WIGoogle Scholar
  25. Gholz HL (1982) Environmental limits on aboveground net primary production, leaf area, and biomass in vegetation zones of the Pacific Northwest. Ecology 63: 469–481Google Scholar
  26. Gholz HL, Fisher RF (1982) Organic matter production and distribution in slash pine (Pinus eliotti) plantations. Ecology 63: 1827–1839Google Scholar
  27. Gholz HT, Vogel SA, Cropper WP, McKelvey K, Ewel KC, Teskey RO, Curran PJ (1991) Dynamics of canopy structure and light interception in Pinus eliotti stands, North Florida. Ecol Monogr 61: 33–51Google Scholar
  28. Goudrian J, Van Laar HH (1978) Relations between leaf resistance, CO2 concentration, and CO2 assimilation in maize, beans, lalang grass and sunflower. Photosynthetica 12: 241–249Google Scholar
  29. Hinckley TM, Aslin RG, Aubuchon RR, Metcalf CL, Roberts JE (1978) Leaf conductance and photosynthesis in four species of oak-hickory forest type. Forest Science 24: 73–84Google Scholar
  30. Hunt ER, Running SW, Federer CA (1991) Extrapolating plant water flow resistances and capacitances to regional scales. Agricul For Meteorol 54: 169–195Google Scholar
  31. Leverenz JW (1981) Photosynthesis and transpiration in large forest-grown Douglas-fir: diurnal variation. Can J Bot 59: 349–356Google Scholar
  32. Likens GE, Bormann FH (1970) Chemical analysis of plant tissues from the Hubbard Brook ecosystem in New Hampshire. Yale University School of Forestry Bulletin No. 9Google Scholar
  33. Marshall JD, Waring RH (1985) Predicting fine root production and turnover by monitoring root starch and soil temperature. Can J For Res 15: 791–800Google Scholar
  34. McMurtrie RE, Rook DA, Kelliher FM (1990) Modelling the yield of Pinus radiata on a site limited by water and nitrogen. Forest Ecol Manag 30: 381–413Google Scholar
  35. McNaughton KG, Jarvis PG (1991) Effects of spatial scale on stomatal control of transpiration. Agricul For Meteorol 54: 279–302Google Scholar
  36. Mitchell JFB, Manabe S, Meleshko V, Tokioka T (1990) Equilibrium climate change - and its implications for the future. In: Houghton JT, Jenkins GJ, Ephraums JJ (eds) Climate Change: The IPCC Scientific Assessment. Cambridge University Press, Cambridge, pp 131–172Google Scholar
  37. Monk CD, Day FP (1988) Biomass, primary production and selected nutrient budgets for an undisturbed hardwood watershed. In: Swank WT, Crossley DA (eds) Forest Hydrology and Ecology at Coweeta. Springer-Verlag, New York, pp 151–160Google Scholar
  38. Monson RK, Grant MC (1989) Experimental studies of ponderosa pine. III. Differences in photosynthesis, stomatal conductance, and water-use efficiency between two genetic lines. Am J Bot 76: 1041–1047Google Scholar
  39. Montieth JL (1988) Does transpiration limit the growth of vegetation or vice versa? J Hydrol 100: 57–68Google Scholar
  40. Mooney HA, Drake BG, Luxmoore RJ, Oechel WC, Pitelka LF (1991) Predicting ecosystem response to elevated CO2 concentrations. BioScience 41: 96–104Google Scholar
  41. Mooney HA, Gulmon SL (1982) Constraints on leaf structure and function in relation to herbivory. BioScience 32: 198–206Google Scholar
  42. Nadelhoffer KJ, Aber JD, Melillo JM (1983) Leaf-litter production and soil organic matter dynamics along a nitrogen mineralization gradient in southern Wisconsin (USA). Can J For Res 13: 12–21Google Scholar
  43. Nadelhoffer KJ, Aber JD, Melillo JM (1985) Fine root production in relation to total net primary production along a nitrogen availability gradient in temperate forests: A new hypothesis. Ecology 66: 1377–1390Google Scholar
  44. Parton WJ, Stewart JWB, Cole CV (1988) Dynamics of C, N, P, and S in grassland soils: a model. Biogeochemistry 5: 109–132Google Scholar
  45. Pastor J, Post WM (1986) Influence of climate, soil moisture, and succession on forest carbon and nitrogen cycles. Biogeochemistry 2: 3–28Google Scholar
  46. Pearson JA, Fahey TJ, Knight DH (1984) Biomass and leaf area in contrasting lodgepole pine forests. Can J For Res 14: 259–265Google Scholar
  47. Raich JW, Nadelhoffer KJ (1989) Below ground carbon allocation in forest ecosystems: Global trends. Ecology 70: 1346–1354Google Scholar
  48. Reich PB, Abrams MD, Ellsworth DS, Kruger EL, Tabone TJ (1990) Fire affects ecophysiology and community dynamics of central Wisconsin oak forest regeneration. Ecology 71: 2179–2190Google Scholar
  49. Running SW (1980) Environmental and physiological control of water flux through Pinus contorta. Can J For Res 10: 82–91Google Scholar
  50. Running SW, Coughlan JC (1988) A general model of forest ecosystem processes for regional applications. I. Hydrologic balance, canopy gas exchange and primary production processes. Ecol Model 42: 125–154Google Scholar
  51. Ryan MG (1992) A simple method for estimating gross carbon budgets for vegetation in forest ecosystems. Tree Physiol 9: 255–266Google Scholar
  52. Schulze E-D, Hall AE (1982) Stomatal responses, water loss and CO2 assimilation rates of plants in contrasting environments. In: Lange OL, Nobel PS, Zeigler H (eds) Encyclopedia of Plant Physiology. Springer-Verlag, Berlin, pp 181–230Google Scholar
  53. Schulze E-D, Kuppers M (1979) Short-term and long-term effects of plant water deficits on stomatal response to humidity in Corylus avellana L Planta 146: 319–326Google Scholar
  54. Sinclair TR, Tanner CB, Bennett JM (1984) Water-use efficiency in crop production. BioScience 34: 36–40Google Scholar
  55. Slaughter CW, Viereck LA (1986) Climatic characteristics of the taiga in interior Alaska. In: Van Cleve K, Chapin FS, Flanagan PW, Viereck LA, Dyrness CT (eds) Forest Ecosystems in the Alaskan Taiga. Springer-Verlag, New York, pp 22–43Google Scholar
  56. Sollins P, Grier CC, McCorison FM, Cromack K, Fogel R, Fredericksen RL (1980) The internal element cycles of an old-growth Douglas-fir ecosystem in western Oregon. Ecol Monogr 50: 261–285Google Scholar
  57. Swift LR, Cunningham GB, Douglass JE (1988) Climatology and hydrology. In: Swank WT, Crossley DA (eds) Forest Hydrology and Ecology and Coweeta. Springer-Verlag, New York, pp 35–56Google Scholar
  58. Tanner CB, Sinclair TR (1983) Efficient water use in crop production: research or re-search. In: Taylor H, (eds) Limitations to Efficient Water Use in Crop Production American Society of Agronomy, Madison WI, pp 1–28Google Scholar
  59. Tenhunen JD, Pearcy RW, Lange OL (1987) Diurnal variations in leaf conductance and gas exchange in natural environments. In: Zeiger E, Farquhar GD, Cowan IR (eds) Stomatal Function. Stanford University Press, Stanford, CA, pp 323–351Google Scholar
  60. Tenhunen JD, Sala Serra A, Harley PC, Dougherty RL, Reynolds JF (1990) Factors influencing carbon fixation and water used by mediterranean sclerophyll shrubs during summer drought. Oecologia 82: 381–393Google Scholar
  61. Van Cleve K, Dyrness CT, Viereck LA, Fox J, Chapin FS III, Oechel W (1983) Taiga ecosystems in interior Alaska. BioScience 33: 39–44Google Scholar
  62. Whittaker RH, Bormann FH, Likens GE, Siccama TG (1974) The Hubbard Brook Ecosystem Study: Forest biomass and production. Ecol Mono 44: 233–254Google Scholar
  63. Wong SC, Cowan RR, Farquhar GD (1979) Stomatal conductance correlations with photosynthetic capacity. Nature 282: 424–426Google Scholar
  64. Zur B, Jones JM (1984) Diurnal changes in the instantaneous water use efficiency of a soybean crop. Agric For Meteorol 33: 41–51Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • John D. Aber
    • 1
  • C. Anthony Federer
    • 2
  1. 1.Institute for the Study of Earth, Oceans and SpaceUniversity of New HampshireDurhamUSA
  2. 2.Northeastern Forest Experiment StationU.S.D.A. Forest ServiceDurhamUSA

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