Abstract
Recent projections of climatic change have focused a great deal of scientific and public attention on patterns of carbon (C) cycling as well as its controls, particularly the factors that determine whether an ecosystem is a net source or sink of atmospheric carbon dioxide (CO2). Net ecosystem production (NEP), a central concept in C-cycling research, has been used by scientists to represent two different concepts. We propose that NEP be restricted to just one of its two original definitions—the imbalance between gross primary production (GPP) and ecosystem respiration (ER). We further propose that a new term—net ecosystem carbon balance (NECB)—be applied to the net rate of C accumulation in (or loss from [negative sign]) ecosystems. Net ecosystem carbon balance differs from NEP when C fluxes other than C fixation and respiration occur, or when inorganic C enters or leaves in dissolved form. These fluxes include the leaching loss or lateral transfer of C from the ecosystem; the emission of volatile organic C, methane, and carbon monoxide; and the release of soot and CO2 from fire. Carbon fluxes in addition to NEP are particularly important determinants of NECB over long time scales. However, even over short time scales, they are important in ecosystems such as streams, estuaries, wetlands, and cities. Recent technological advances have led to a diversity of approaches to the measurement of C fluxes at different temporal and spatial scales. These approaches frequently capture different components of NEP or NECB and can therefore be compared across scales only by carefully specifying the fluxes included in the measurements. By explicitly identifying the fluxes that comprise NECB and other components of the C cycle, such as net ecosystem exchange (NEE) and net biome production (NBP), we can provide a less ambiguous framework for understanding and communicating recent changes in the global C cycle.
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References
Aber JD, Melillo JM. 1991. Terrestrial ecosystems. Orlando (FL): Saunders College Publishing
Aber JD, Melillo JM. 2001. Terrestrial ecosystems. 2nd ed. San Diego (CA): Harcourt–Academic Press
Andrews JA, Schlesinger WH. 2001. Soil CO2 dynamics, acidification, and chemical weathering in a temperate forest with experimental CO2 enrichment. Global Biogeochem Cycles 15:149–62
Aubinet M, Heinesch B, Yernaux M. 2003. Horizontal and vertical CO2 advection in a sloping forest. Boundary Layer Meteorol 108:397–417
Aumont O, Orr JC, Monfray P, Ludwig W, Amiotte-Suchet P, Probst J-L. 2001. Riverine-driven interhemispheric transport of carbon. Global Biogeochemical Cycles 15:393–405
Baldocchi DD. 2003. Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems: past, present and future. Global Change Biol 9:479–92
Bousquet P, Peylin P, Ciais P, Le Quere C, Friedlingstein P, Tans PP. 2000. Regional changes in carbon dioxide fluxes of land and oceans since 1980. Science 290:1342–6
Chapin FS III, Matson PA, Mooney HA. 2002. Principles of terrestrial ecosystem ecology. New York: Springer-Verlag
Ciais P, Janssens J, Shvidenko A, Wirth C, Malhi Y, Grave J, Schulze E-D, Heimann M, Phillips O, Dolman AJ. 2005. The potential for rising CO2 to account for the observed uptake of carbon by tropical, temperate and boreal forest biomes. Griffith H, Jarvis P, editors. The Carbon Balance of Forest Biomes. Milton Park, UK: Taylor and Francis. p 109–150
Clark DA, Brown S, Kicklighter DW, Chambers JQ, Thomlinson JR, Ni J. 2001. Measuring net primary production in forests: concepts and field methods. Ecol Appl 11:356–70
Cox PM, Betts RA, Jones CD, Spall SA, Totterdell IJ. 2000. Acceleration of global warming due to carbon-cycle feedbacks in a coupled climate model. Nature 408:184–7
Falge E, Baldocchi D, Tenhunen J, Aubinet M, Bakwin P, Berbigier P, Bernhofer C, Burba G, Clement R, Davis KJ. 2002. Seasonality of ecosystem respiration and gross primary production as derived from FLUXNET measurements. Agricultural and Forest Meteorology 113:53–74
Fisher SG, Likens GE. 1973. Energy flow in Bear Brook, New Hampshire: an integrative approach to stream ecosystem metabolism. Ecol Monogr 43:421–39
Fung IY, Doney SC, Lindsay K, John J. 2005. Evolution of carbon sinks in a changing climate. Proc Nat’l Acad Sci 102:11201–6
Guenther A. 2002. The contribution of reactive carbon emissions from vegetation to the carbon balance of terrestrial ecosystems. Chemosphere 49:837–44
Hanson PC, Bade DL, Carpenter SR, Kratz TK. 2003. Lake metabolism: relationships with dissolved organic carbon and phosphorus. Limnol Oceanogr 48:1112–9
Heimann M, Esser G, Haxeltine A, Kaduk J, Kicklighter DW, Knorr W, Kohlmaier GH, McGuire AD, Melillo J, Moore B, Otto RD, Prentice IC, Sauf W, Schloss A, Sitch S, Wittenberg U, Wurth G. 1998. Evaluation of terrestrial carbon cycle models through simulations of the seasonal cycle of atmospheric CO2: First results of a model intercomparison study. Global Biogeochemical Cycles 12:1–24
Howarth RW. 1984. The ecological significance of sulfur in the energy dynamics of salt marsh and marine sediments. Biogeochemistry 1:5–27
Howarth RW, Teal JM. 1980. Energy flow in a salt marsh ecosystem: the role of reduced inorganic sulfur compounds. Am Nat 116:862–72
Howarth RW, Michaels AF. 2000. The measurement of primary production in aquatic ecosystems. In: Sala OE, Jackson RB, Mooney HA, Howarth RW, editors. Methods in ecosystem science. New York: Springer-Verlag. p 72–85
Howarth RW, Schneider R, Swaney D. 1996. Metabolism and organic carbon fluxes in the tidal, freshwater Hudson River. Estuaries 19:848–65
Jannasch HW, Mottl MJ. 1985. Geomicrobiology of deep-sea hydrothermal vents. Science 229:717–25
Janssens IA, Freibauer A, Ciais P, Smith P, Nabuurs GJ, Folberth G, Sehlamadinger B, Hutjes RWA, Ceulemans R, Schulze ED, Valentini D, Dolman AJ. 2003. Europe’s terrestrial biosphere absorbs 7 to 12% of European anthropogenic CO2 emissions. Science 300:1538–1542
Kesselmeier J, Ciccioli P, Kuhn U, Stefani P, Biesenthal T, Rottenberger S, Wolf A, Vitullo M, Valentini R, Nobre A, Kabat P, Andreae MO. 2002. Volatile organic compound emissions in relation to plant carbon fixation and the terrestrial carbon budget. Global Biogeochemical Cycles 16:10.1029/2001GB001813
Kirschbaum MUF, Farquhar GD. 1984. Temperature dependence of whole-leaf photosynthesis in Eucalyptus pauciflora Sieb. ex Spreng. Aust J Plant Physiol 11:519–38
Kling GW, Kipphut GW, Miller MC. 1991. Arctic lakes and streams as gas conduits to the atmosphere: implications for tundra carbon budgets. Science 251:298–301
Lieth H, 1975. Modeling the primary productivity of the world. In: Lieth H, Whittaker RH, editors. Primary productivity of the biosphere. Berlin: Springer-Verlag. p 237–63
Lindeman RL. 1942. The trophic-dynamic aspects of ecology. Ecology 23:399–418
Long SP, Moya EG, Imbamba SK, Kamnalrut A, Piedade MTF, Scurlock JMO, Shen YK, Hall DO. 1989. Primary productivity of natural grass ecosystems of the tropics: A Reappraisal. Plant and Soil 115:155–66
Loreto F, Delfine S, Di Marco G. 1999. Estimation of photorespiratory carbon dioxide recycling during photosynthesis. Aust J Plant Physiol 26:733–6
Loreto F, Velikova V, Di Marco G. 2001. Respiration in the light measured by (CO2)-C-12 emission in (CO2)-C-13 atmosphere in maize leaves. Aust J Plant Physiol 28:1103–8
Lovett GM, Cole JJ, Pace ML. 2006. Is net ecosystem production equal to ecosystem carbon storage? Ecosystems. Forthcoming
Matson PA, Parton WJ, Power AG, Swift MJ. 1997. Agricultural intensification and ecosystem properties. Science 227:504–9
Odum EP. 1959. Fundamentals of ecology. Philadelphia: WB Saunders
Odum HT. 1956. Primary production in flowing waters. Limnol Oceanogr 1:102–17
Ovington JD. 1962. Quantitative ecology and the woodland ecosystem concept. Adv Ecol Res 1:103–92
Peterson BJ. 1980. Aquatic primary productivity and the 14C-CO2 method: a history of the productivity problem. Annu Rev Ecol Syst 11:359–85
Prentice IC, Farquhar GD, Fasham MJR, Goulden ML, Heimann M, Jaramillo VJ, Kheshgi HS, Le Quéré C, Scholes RJ, Wallace DWR. 2001. The carbon cycle and atmospheric carbon dioxide. Houghton JT et al., editors. Climate Change 2001: The Scientific Basis. Cambridge: Cambridge University Press. p 183–237
Randerson JT, Chapin FS III, Harden J, Neff JC, Harmon ME. 2002. Net ecosystem production: a comprehensive measure of net carbon accumulation by ecosystems. Ecol Appl 12:937–47
Richey JE, Melack JM, Aufdenkampe AK, Ballester VM, Hess LL. 2002. Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2. Nature 416:617–20
Richter DD, Markewitz D, Trumbore SE. 1999. Rapid accumulation and turnover of soil carbon in a reestablishing forest. Nature 400:56–8
Roberts BJ, Owens TG, Ostrom NE, Howarth RW. Aquatic ecosystem respiration rates are not constant over diel cycles: direct quantification using dissolved oxygen concentration and isotopic composition in experimental ponds. Limnol Oceanogr. Forthcoming
Rodin LE, Bazilevich NI. 1967. Production and mineral cycling in terrestrial vegetation. Edinburgh: Oliver & Boyd
Rosenbloom NA, Doney SC, Schimel DS. 2001. Geomorphic evolution of soil texture and organic matter in eroding landscapes. Global Biogeochem Cycles 15:365–81
Sala OE, Austin AT. 2000. Methods of estimating aboveground net primary productivity. In: Sala OE, Jackson RB, Mooney HA, Howarth RW, editors. Methods in ecosystem science. New York: Springer-Verlag. p 31–43
Schimel DS. 1995. Terrestrial ecosystems and the carbon cycle. Global Change Biol 1:77–91
Schlesinger WH. 1985. The formation of caliche in soils of the Mojave Desert, California. Geochim Cosmochim Acta 49:57–66
Schlesinger WH. 1990. Evidensce from chronosequence studies for a low carbon-storage potential of soils. Nature 348:232–4
Schlesinger WH. 1997. Biogeochemistry: an analysis of global change. 2nd ed. San Diego (CA): Academic Press
Schlesinger WH, Melack JM. 1981. Transport of organic carbon in the world’s rivers. Tellus 33:172–87
Schulze E-D, Heimann M. 1998. Carbon and water exchange of terrestrial systems. In: Halloway JN, Melillo J, editors. Asian change in the context of global change. Cambridge (UK): Cambridge University Press. p 145–61
Schulze E-D, Lloyd J, Kelliher FM, Wirth C, Rebmann C, Luhker B, Mund M, Knohl A, Milyhukova JM, Schulze W, Ziegler W, Varlagin AB, Sogachev AF, Valentini R, Dore S, Grigoriev S, Kolle O, Panfyorov MI, Tchebakova N, Vygodskaya NN. 1999. Productivity of forests in the Eurosiberian boreal region and their potential to act as a carbon sink—a synthesis. Global Change Biology 5:703–722
Schulze E-D, Wirth C, Heimann M. 2000. Climate change: managing forests after Kyoto. Science 289:2058–9
Schulze E-D, Wirth C, Heimann M. 2002. Carbon fluxes of the Eurosiberian region. Environ Control Biol 40:249–58
Stallard RF. 1998. Terrestrial sedimentation and the carbon cycle: coupling weathering and erosion to carbon burial. Global Biogeochem Cycles 12:231–57
Wigley TML, Richels R, Edmonds JA. 1996. Economic and environmental choices in the stabilization of atmospheric CO2 concentrations. Nature 379:240–3
Woodwell GM, Whittaker RH. 1968. Primary production in terrestrial communities. Am Zool 8:19–30
Woodwell GM, Mackenzie FT. 1995. Biotic feedbacks in the global climatic system: will the warming feed the warming? New York: Oxford University Press
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We thank Gus Shaver, Stuart Fisher, and the two anonymous reviewers for their insightful comments.
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Chapin, F.S., Woodwell, G.M., Randerson, J.T. et al. Reconciling Carbon-cycle Concepts, Terminology, and Methods. Ecosystems 9, 1041–1050 (2006). https://doi.org/10.1007/s10021-005-0105-7
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DOI: https://doi.org/10.1007/s10021-005-0105-7