Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-14T22:24:51.218Z Has data issue: false hasContentIssue false
  • English
  • Français

Application of a conceptual framework to interpret variability in rangeland responses to atmospheric CO2 enrichment

Published online by Cambridge University Press:  05 October 2010

H. W. POLLEY ,
J. A. MORGAN  and
P. A. FAY
H. W. POLLEY*
Affiliation:
U.S. Department of Agriculture, Agricultural Research Service, Grassland, Soil and Water Research Laboratory, Temple, TX 76502, USA
J. A. MORGAN
Affiliation:
U.S. Department of Agriculture, Agricultural Research Service, Crops Research Laboratory, Ft. Collins, CO 80526, USA
P. A. FAY
Affiliation:
U.S. Department of Agriculture, Agricultural Research Service, Grassland, Soil and Water Research Laboratory, Temple, TX 76502, USA
*
*To whom all correspondence should be addressed. E-mail: wayne.polley@ars.usda.gov
Get access Rights & Permissions [Opens in a new window]

Summary

Plant productivity and other ecosystem processes vary widely in their responses to experimental increases in atmospheric carbon dioxide (CO2) concentration. A conceptual framework first suggested by Chapin et al. (1996) was adapted to address the question of why CO2 effects on primary productivity vary so greatly among rangelands and among years for a given ecosystem. The ‘interactive controls’ framework is based on the premise that the influence of elevated CO2 on productivity is governed by a set of internal variables that interact dynamically with ecosystem processes. These interactive controls, which include regional climate, soil resource supply, major functional groups of organisms and disturbance regimes, both regulate CO2 effects on ecosystems and respond to CO2 effects. Changes in interactive controls resulting from CO2 enrichment may feed back to dampen or amplify ecosystem responses to CO2. Most feedbacks from interactive controls will be negative and dampen CO2 effects on ecosystems. Negative feedbacks promote homeostasis in ecosystem processes and reduce the response of plant productivity to CO2. Positive feedbacks on CO2 responses are fewer, but can sustain or even increase benefits of CO2 enrichment for productivity. Positive feedbacks on CO2 responses occur most frequently through changes in plant species and functional group composition. Understanding positive and negative feedbacks on CO2 responses could be one key to predicting consequences of CO2 enrichment for rangeland productivity and other processes.

Type
Climate Change and Agriculture
Information
The Journal of Agricultural Science , Volume 149 , Issue 1 , February 2011 , pp. 1 - 14
Copyright
Copyright © Cambridge University Press 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Anderson, L. J., Maherali, H., Johnson, H. B., Polley, H. W. & Jackson, R. B. (2001). Gas exchange and photosynthetic acclimation over subambient to elevated CO2 in a C3–C4 grassland. Global Change Biology 7, 693–707.CrossRefGoogle Scholar
Baker, J. T. & Allen, L. H. Jr. (1993). Contrasting crop species responses to CO2 and temperature: rice, soybean and citrus. Vegetatio 104/105, 239–260.CrossRefGoogle Scholar
Belote, R. T., Weltzin, J. F. & Norby, R. J. (2003). Response of an understory plant community to elevated [CO2] depends on differential responses of dominant invasive species and is mediated by soil water availability. New Phytologist 161, 827–835.CrossRefGoogle Scholar
Bond, W. J. (2008). What limits trees in C4 grasslands and savannas? Annual Review of Ecology, Evolution, and Systematics 39, 641–659.CrossRefGoogle Scholar
Brown, J. R. & Archer, S. (1999). Shrub invasion of grassland: Recruitment is continuous and not regulated by herbaceous biomass or density. Ecology 80, 2385–2396.CrossRefGoogle Scholar
Bunce, J. A., Wilson, K. B. & Carlson, T. N. (1997). The effect of doubled CO2 on water use by alfalfa and orchard grass: simulating evapotranspiration using canopy conductance measurements. Global Change Biology 3, 81–87.CrossRefGoogle Scholar
Burke, I. C., Lauenroth, W. K. & Parton, W. J. (1997). Regional and temporal variation in net primary production and nitrogen mineralization in grasslands. Ecology 78, 1330–1340.CrossRefGoogle Scholar
Campbell, B. D., Stafford Smith, D. M. & Mckeon, G. M. (1997). Elevated CO2 and water supply interactions in grasslands: a pastures and rangelands management perspective. Global Change Biology 3, 177–187.CrossRefGoogle Scholar
Canadell, J. G., Le Quéré, C., Raupach, M. R., Field, C. B., Buitenhuis, E. T., Ciais, P., Conway, T. J., Gillett, N. P., Houghton, R. A. & Marland, G. (2007) Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks. Proceedings of the National Academy of Sciences, USA 104, 18866–18870.CrossRefGoogle ScholarPubMed
Chapin, F. S. III, Torn, M. S. & Tateno, M. (1996). Principles of ecosystem sustainability. American Naturalist 148, 1016–1037.CrossRefGoogle Scholar
Cotrufo, M. F., Ineson, P. & Scott, A. (1998). Elevated CO2 reduces the nitrogen concentration of plant tissues. Global Change Biology 4, 43–54.CrossRefGoogle Scholar
Dijkstra, F. A., Pendall, E., Mosier, A. R., King, J. Y., Milchunas, D. G. & Morgan, J. A. (2008). Long-term enhancement of N availability and plant growth under elevated CO2 in a semi-arid grassland. Functional Ecology 22, 975–982.CrossRefGoogle Scholar
Dukes, J. S., Chiariello, N. R., Cleland, E. E., Moore, L. A., Shaw, M. R., Thayer, S., Tobeck, T., Mooney, H. A. & Field, C. B. (2005). Responses of grassland production to single and multiple global environmental changes. PLoS Biology 3, e319.CrossRefGoogle ScholarPubMed
Edwards, G. R., Clark, H. & Newton, P. C. D. (2001). Carbon dioxide enrichment affects seedling recruitment in an infertile, permanent grassland grazed by sheep. Oecologia 127, 383–394.CrossRefGoogle Scholar
Fajer, E. D., Bowers, M. D. & Bazzaz, F. A. (1991). Performance and allocation patterns of the perennial herb, Plantago lanceolata, in response to simulated herbivory and elevated CO2 environments. Oecologia 87, 37–42.CrossRefGoogle Scholar
Fay, P. A., Kaufman, D. M., Nippert, J. B., Carlisle, J. D. & Harper, C. W. (2008). Changes in grassland ecosystem function due to extreme rainfall events: Implications for responses to climate change. Global Change Biology 14, 1600–1608.CrossRefGoogle Scholar
Fay, P. A., Kelley, A. M., Procter, A. C., Hui, D., Jin, V. L., Jackson, R. B., Johnson, H. B. & Polley, H. W. (2009). Primary productivity and water balance of grassland vegetation on three soils in a continuous CO2 gradient: initial results from the lysimeter CO2 gradient experiment. Ecosystems 12, 699–714.CrossRefGoogle Scholar
Field, C. B., Jackson, R. B. & Mooney, H. A. (1995). Stomatal responses to increased CO2: implications from the plant to the global scale. Plant, Cell and Environment 18, 1214–1225.CrossRefGoogle Scholar
Follett, R. F. & Reed, D. A. (2010). Soil carbon sequestration in grazing lands: societal benefits and policy implications. Rangeland Ecology and Management 63, 4–15.CrossRefGoogle Scholar
Fredeen, A. L., Randerson, J. T., Holbrook, N. M. & Field, C. B. (1997). Elevated atmospheric CO2 increases water availability in a water-limited grassland ecosystem. Journal of the American Water Resources Association 33, 1033–1039.CrossRefGoogle Scholar
Gill, R. A., Polley, H. W., Johnson, H. B., Anderson, L. J., Maherali, H. & Jackson, R. B. (2002). Nonlinear grassland responses to past and future atmospheric CO2. Nature 417, 279–282.CrossRefGoogle Scholar
Gill, R. A., Anderson, L. J., Polley, H. W., Johnson, H. B. & Jackson, R. B. (2006) Potential nitrogen constraints on soil carbon sequestration under low and elevated atmospheric CO2. Ecology 87, 41–52.CrossRefGoogle ScholarPubMed
Grünzweig, J. M. & Körner, C. (2001). Growth, water and nitrogen relations in grassland model ecosystems of the semi-arid Negev of Israel exposed to elevated CO2. Oecologia 128, 251–262.CrossRefGoogle Scholar
Hamilton, E. W. III, Heckathorn, S. A., Joshi, P., Wang, D. & Barua, D. (2008). Interactive effects of elevated CO2 and growth temperature on the tolerance of photosynthesis to acute heat stress in C3 and C4 species. Journal of Integrative Plant Biology 50, 1375–1387.CrossRefGoogle ScholarPubMed
Harmens, H., Williams, P. D., Peters, S. L., Bambrick, M. T., Hopkins, A. & Ashenden, T. W. (2004). Impacts of elevated atmospheric CO2 and temperature on plant community structure of a temperate grassland are modulated by cutting frequency. Grass and Forage Science 59, 144–156.CrossRefGoogle Scholar
Heimann, M. & Reichstein, M. (2008). Terrestrial ecosystem carbon dynamics and climate feedbacks. Nature 451, 289–292.CrossRefGoogle ScholarPubMed
Heisler-White, J. L., Blair, J. M., Kelly, E. F., Harmoney, K. & Knapp, A. K. (2009). Contingent productivity responses to more extreme rainfall regimes across a grassland biome. Global Change Biology 15, 2894–2904.CrossRefGoogle Scholar
Henry, H. A. L., Chiariello, N. R., Vitousek, P. M., Mooney, H. A. & Field, C. B. (2006). Interactive effects of fire, elevated carbon dioxide, nitrogen deposition, and precipitation on a California annual grassland. Ecosystems 9, 1066–1075.CrossRefGoogle Scholar
Howe, H. F. (1994). Managing species diversity in tallgrass prairies: assumptions and implications. Conservation Biology 8, 691–704.CrossRefGoogle Scholar
Hungate, B. A., Chapin, F. S. III, Zhong, H., Holland, E. A. & Field, C. B. (1997). Stimulation of grassland nitrogen cycling under carbon dioxide enrichment. Oecologia 109, 149–153.CrossRefGoogle Scholar
Idso, S. B., Kimball, B. A., Akin, D. E. & Kridler, J. (1993). A general relationship between CO2-induced reductions in stomatal conductance and concomitant increases in foliage temperature. Environmental and Experimental Botany 33, 443–446.CrossRefGoogle Scholar
IPCC (2007). Climate Change 2007: The Physical Science Basis. Summary for Policymakers. Cambridge, UK: Cambridge University Press.Google Scholar
Jackson, R. B., Sala, O. E., Field, C. B. & Mooney, H. A. (1994). CO2 alters water use, carbon gain, and yield for the dominant species in a natural grassland. Oecologia 98, 257–262.CrossRefGoogle Scholar
Jansen, E., Overpeck, J., Briffa, K. R., Duplessy, J.-C., Joos, F., Masson-Delmotte, V., Olago, D., Otto-Bliesner, B., Peltier, W. R., Rahmstorf, S., Ramesh, R., Raynaud, D., Rind, D., Solomina, O., Villalba, R. & Zhang, D. (2007). Palaeoclimate. In Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Eds Solomon, S., Qin, D., Manning, M., Marquis, M., Avert, K., Tignor, M. M. B., Miller, H. L. & Chen, Z.), pp. 434–497. Cambridge, UK: Cambridge University Press.Google Scholar
Jenny, H. (1941). Factors of Soil Formation: A System of Quantitative Pedology. New York: McGraw-Hill.CrossRefGoogle Scholar
Joel, G., Chapin, F. S. III, Chiariello, N. R., Thayer, S. S. & Field, C. B. (2001). Species-specific responses of plant communities to altered carbon and nutrient availability. Global Change Biology 7, 435–450.CrossRefGoogle Scholar
Jouzel, J., Barkov, N. I., Barnola, J. M., Bender, M., Chappellaz, J., Genthon, C., Kotlyakov, V. M., Lipenkov, V., Lorius, C., Petit, J. R., Raynaud, D., Raisbeck, G., Ritz, C., Sowers, T., Stievenard, M., Yiou, F. & Yiou, P. (1993). Extending the Vostok ice-core record of paleoclimate to the penultimate glacial period. Nature 364, 407–412.CrossRefGoogle Scholar
Keeling, R. F., Piper, S. C., Bollenbacher, A. F. & Walker, J. S. (2009). Atmospheric CO2 records from sites in the SIO air sampling network. In Trends: A Compendium of Data on Global Change. Oak Ridge, TN: Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, US Department of Energy. doi: 10.3334/CDIAC/atg.035. Available online at http://cdiac.ornl.gov/trends/co2/sio-mlo.html (verified 3 August 2010).Google Scholar
Kimball, B. A., Pinter, P. J. Jr, Garcia, R. L., LaMorte, R. L., Wall, G. W., Hunsaker, D. J., Wechsung, G., Wechsung, F. & Kartschall, T. (1995). Productivity and water use of wheat under free-air CO2 enrichment. Global Change Biology 1, 429–442.CrossRefGoogle Scholar
King, J. Y., Mosier, A. R., Morgan, J. A., LeCain, D. R., Milchunas, D. G. & Parton, W. J. (2004). Plant nitrogen dynamics in shorgrass steppe under elevated atmospheric carbon dioxide. Ecosystems 7, 147–160.CrossRefGoogle Scholar
Knapp, A. K. & Smith, M. D. (2001). Variation among biomes in temporal dynamics of aboveground primary production. Science 291, 481–484.CrossRefGoogle ScholarPubMed
Kramp, B. A., Ansley, R. J. & Tunnell, T. R. (1998). Survival of mesquite seedlings emerging from cattle and wildlife feces in a semi-arid grassland. Southwestern Naturalist 43, 300–312.Google Scholar
Körner, C., Diemer, M., Schäppi, B., Niklaus, P. A. & Arnone, J. (1997). The responses of alpine grassland to four seasons of CO2 enrichment: a synthesis. Acta Oecologica 18, 165–175.CrossRefGoogle Scholar
Lau, J. A. & Tiffin, P. (2009). Elevated carbon dioxide concentrations indirectly affect plant fitness by altering plant tolerance to herbivory. Oecologia 161, 401–410.CrossRefGoogle ScholarPubMed
Leadley, P. W., Niklaus, P. A., Stocker, R. & Körner, C. (1999). A field study of the effects of elevated CO2 on plant biomass and community structure in a calcareous grassland. Oecologia 118, 39–49.CrossRefGoogle Scholar
Long, S. P., Ainsworth, E. A., Leakey, A. D. B., Nösberger, J. & Ort, D. R. (2006). Food for thought: lower-than-expected crop yield stimulation with rising CO2 concentrations. Science 312, 1918–1921.CrossRefGoogle ScholarPubMed
Luo, Y., Su, B., Currie, W. S., Dukes, J. S., Finzi, A., Hartwig, U., Hungate, B., McMurtrie, R. E., Oren, R., Parton, W. J., Pataki, D. E., Shaw, M. R., Zak, D. R. & Field, C. B. (2004). Progressive nitrogen limitation of ecosystem responses to rising atmospheric carbon dioxide. BioScience 54, 731–739.CrossRefGoogle Scholar
Mack, R. N. (1986). Alien plant invasion into the intermountain west: a case history. In Ecology of Biological Invasions of North America and Hawaii (Eds Mooney, H. A. & Drake, J. A.), pp. 191–213. New York, NY: Springer-Verlag.CrossRefGoogle Scholar
Maherali, H., Reid, C. D., Polley, H. W., Johnson, H. B. & Jackson, R. B. (2002). Stomatal acclimation over a subambient to elevated CO2 gradient in a C3/C4 grassland. Plant, Cell and Environment 25, 557–566.CrossRefGoogle Scholar
McNaughton, K. G. & Jarvis, P. G. (1991). Effects of spatial scale on stomatal control of transpiration. Agricultural and Forest Meteorology 54, 279–302.CrossRefGoogle Scholar
Mielnick, P. S., Dugas, W. A., Johnson, H. B., Polley, H. W. & Sanabria, J. (2001). Net grassland carbon flux over a subambient to superambient CO2 gradient. Global Change Biology 7, 747–754.CrossRefGoogle Scholar
Milchunas, D. G., Mosier, A. R., Morgan, J. A., LeCain, D. R., King, J. Y. & Nelson, J. A. (2005). Elevated CO2 and defoliation effects on a shortgrass steppe: forage quality versus quantity for ruminants. Agriculture, Ecosystems and Environment 111, 166–184.CrossRefGoogle Scholar
Morgan, J. A. (2005). Rising atmospheric CO2 and global climatic change: management implications for grazing lands. In Grasslands: Developments, Opportunities, Perspectives (Eds Reynolds, S. G. & Frame, J.), pp. 245–272. Enfield, USA: FAO and Science Publishers Inc.Google Scholar
Morgan, J. A., LeCain, D. R., Mosier, A. R. & Milchunas, D. G. (2001). Elevated CO2 enhances water relations and productivity and affects gas exchange in C3 and C4 grasses of the Colorado shortgrass steppe. Global Change Biology 7, 451–466.CrossRefGoogle Scholar
Morgan, J. A., Mosier, A. R., Milchunas, D. G., LeCain, D. R., Nelson, J. A. & Parton, W. J. (2004 a). CO2 enhances productivity of the shortgrass steppe, alters species composition, and reduces forage digestibility. Ecological Applications 14, 208–219.CrossRefGoogle Scholar
Morgan, J. A., Pataki, D. E., Körner, C., Clark, H., Del Grosso, S. J., Grünzweig, J. M., Knapp, A. K., Mosier, A. R., Newton, P. C. D., Niklaus, P. A., Nippert, J. B., Nowak, R. S., Parton, W. J., Polley, H. W. & Shaw, M. R. (2004 b). Water relations in grassland and desert ecosystems exposed to elevated atmospheric CO2. Oecologia 140, 11–25.CrossRefGoogle ScholarPubMed
Morgan, J. A., Milchunas, D. G., LeCain, D. R., West, M. & Mosier, A. R. (2007). Carbon dioxide enrichment alters plant community structure and accelerates shrub growth in the shortgrass steppe. Proceedings of the National Academy of Sciences, USA 104, 14724–14729.CrossRefGoogle ScholarPubMed
National Agricultural Statistics Service of USDA. (2006). Statistics on cattle, hogs, and sheep. In Agricultural Statistics (Eds Chapman, F. & Petrone, R. M.), pp. VII-1–VII-62. Washington, DC: US Government Printing Office.Google Scholar
Nelson, J. A., Morgan, J. A., LeCain, D. R., Mosier, A. R., Milchunas, D. G. & Parton, W. J. (2004). Elevated CO2 increases soil moisture and enhances plant water relations in a long-term field study in the semi-arid shortgrass steppe of Northern Colorado. Plant and Soil 259, 169–179.CrossRefGoogle Scholar
Newton, P. C. D., Allard, V., Carran, R. A. & Lieffering, M. (2006). Impacts of elevated CO2 on a grassland grazed by sheep: the New Zealand FACE experiment. In Managed Ecosystems and CO2: Case Studies, Processes, and Perspective (Eds Nösberger, J., Long, S. P., Norby, R. J., Stitt, M., Hendrey, G. R. & Blum, H.), pp. 157–171. Ecological Studies, vol. 187. Berlin: Springer-Verlag.CrossRefGoogle Scholar
Niklaus, P. A. & Körner, C. (2004). Synthesis of a six-year study of calcareous grassland responses to in situ CO2 enrichment. Ecological Monographs 74, 491–511.CrossRefGoogle Scholar
Niklaus, P. A., Spinnler, D. & Körner, C. (1998). Soil moisture dynamics of calcareous grassland under elevated CO2. Oecologia 117, 201–208.CrossRefGoogle Scholar
Niklaus, P. A., Leadley, P. W., Schmid, B. & Körner, C. (2001). A long-term field study on biodiversity×elevated CO2 interactions in grassland. Ecological Monographs 71, 341–356.Google Scholar
Nowak, R. S., Ellsworth, D. S. & Smith, S. D. (2004). Functional responses of plants to elevated atmospheric CO2 – do photosynthetic and productivity data from FACE experiments support early predictions? New Phytologist 162, 253–280.CrossRefGoogle Scholar
Owensby, C. E., Coyne, P. I. & Auen, L. M. (1993). Nitrogen and phosphorus dynamics of a tallgrass prairie ecosystem exposed to elevated carbon dioxide. Plant Cell & Environment 16, 843–850.CrossRefGoogle Scholar
Owensby, C. E., Auen, L. M. & Coyne, P. I. (1994). Biomass production in a nitrogen-fertilized, tallgrass prairie ecosystem exposed to ambient and elevated levels of CO2. Plant and Soil 165, 105–113.CrossRefGoogle Scholar
Owensby, C. E., Ham, J. M., Knapp, A. K., Bremer, D. & Auen, L. M. (1997). Water vapour fluxes and their impact under elevated CO2 in a C4-tallgrass prairie. Global Change Biology 3, 189–195.CrossRefGoogle Scholar
Owensby, C. E., Ham, J. M., Knapp, A. K. & Auen, L. M. (1999). Biomass production and species composition change in a tallgrass prairie ecosystem after long-term exposure to elevated atmospheric CO2. Global Change Biology 5, 497–506.CrossRefGoogle Scholar
Pearcy, R. W. & Ehleringer, J. (1984). Comparative ecophysiology of C3 and C4 plants. Plant Cell and Environment 7, 1–13.CrossRefGoogle Scholar
Pendall, E., Del Grosso, S., King, J. Y., LeCain, D. R., Milchunas, D. G., Morgan, J. A., Moiser, A. R., Ojima, D. S., Parton, W. A., Tans, P. P. & White, J. W. C. (2003). Elevated atmospheric CO2 effects and soil water feedbacks on soil respiration components in a Colorado grassland. Global Biogeochemical Cycles 17, 1046.CrossRefGoogle Scholar
Pepper, D. A., Del Grosso, S. J., McMurtire, R. E. & Parton, W. J. (2005). Simulated carbon sink response of shortgrass steppe, tallgrass prairie and forest ecosystems to rising [CO2], temperature and nitrogen input. Global Biogeochemical Cycles 19, GB1004.CrossRefGoogle Scholar
Petit, J. R., Jouzel, J., Raynaud, D., Barkov, N. I., Barnola, J.-M., Basile, I., Bender, M., Chappellaz, J., Davis, M., Delaygue, G., Delmotte, M., Kotlyakov, V. M., Legrand, M., Lipenkov, V. Y., Lorius, C., Pépin, L., Ritz, C., Saltzman, E. & Stievenard, M. (1999). Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399, 429–436.CrossRefGoogle Scholar
Polley, H. W. (1997). Implications of rising atmospheric carbon dioxide concentration for rangelands. Journal of Range Management 50, 561–577.CrossRefGoogle Scholar
Polley, H. W., Johnson, H. B. & Mayeux, M. S. (1997). Leaf physiology, production, water use, and nitrogen dynamics of the grassland invader Acacia smallii at elevated CO2 concentration. Tree Physiology 17, 89–96.CrossRefGoogle Scholar
Polley, H. W., Morgan, J. A., Campbell, B. D. & Stafford Smith, M. (2000). Crop ecosystem responses to climatic change: rangelands. In Climate Change and Global Crop Productivity (Eds Reddy, K. R. & Hodges, H. F.), pp. 293–314. Wallingford, Oxon, UK: CABI.CrossRefGoogle Scholar
Polley, H. W., Johnson, H. B. & Derner, J. D. (2002 a). Soil- and plant-water dynamics in a C3/C4 grassland exposed to a subambient to superambient CO2 gradient. Global Change Biology 8, 1118–1129.CrossRefGoogle Scholar
Polley, H. W., Johnson, H. B. & Tischler, C. R. (2002 b). Woody invasion of grasslands: evidence that CO2 enrichment indirectly promotes establishment of Prosopis glandulosa. Plant Ecology 164, 85–94.CrossRefGoogle Scholar
Polley, H. W., Johnson, H. B. & Derner, J. D. (2003). Increasing CO2 from subambient to superambient concentrations alters species composition and increases above-ground biomass in a C3/C4 grassland. New Phytologist 160, 319–327.CrossRefGoogle Scholar
Polley, H. W., Dugas, W. A., Mielnick, P. C. & Johnson, H. B. (2007). C3-C4 composition and prior carbon dioxide treatment regulate the response of grassland carbon and water fluxes to carbon dioxide. Functional Ecology 21, 11–18.CrossRefGoogle Scholar
Polley, H. W., Johnson, H. B., Fay, P. A. & Sanabria, J. (2008). Initial response of evapotranspiration from tallgrass prairie vegetation to CO2 at subambient to elevated concentrations. Functional Ecology 22, 163–171.CrossRefGoogle Scholar
Polley, H. W., Emmerich, W., Bradford, J. A., Sims, P. L., Johnson, D. A., Saliendra, N. Z., Svejcar, T., Angell, R., Frank, A. B., Phillips, R. L., Snyder, K. A., Morgan, J. A., Sanabria, J., Mielnick, P. C. & Dugas, W. A. (2010). Precipitation regulates the response of net ecosystem CO2 exchange to environmental variation on United States rangelands. Rangeland Ecology and Management 63, 176–186.CrossRefGoogle Scholar
Read, J. J., Morgan, J. A., Chatterton, N. J. & Harrison, P. A. (1997). Gas exchange and carbohydrate and nitrogen concentrations in leaves of Pascopyrum smithii (C3) and Bouteloua gracilis (C4) at different carbon dioxide concentrations and temperatures. Annals of Botany 79, 197–206.CrossRefGoogle Scholar
Reich, P. B., Tilman, D., Naeem, S., Ellsworth, D. S., Knops, J., Craine, J., Wedin, D. & Trost, J. (2004). Species and functional group diversity independently influence biomass accumulation and its response to CO2 and N. Proceedings of the National Academy of Sciences, USA 101, 10101–10106.CrossRefGoogle ScholarPubMed
Reich, P. B., Hobbie, S. E., Lee, T., Ellsworth, D. S., West, J. B., Tilman, D., Knops, J. M. H., Naeem, S. & Trost, J. (2006). Nitrogen limitation constrains sustainability of ecosystem response to CO2. Nature 440, 922–925.CrossRefGoogle ScholarPubMed
Sage, R. F. (1996). Modification of fire disturbance by elevated CO2. In Carbon Dioxide, Populations, and Communities (Eds Körner, C. & Bazzaz, F. A.), pp. 231–249. San Diego, CA: Academic Press.CrossRefGoogle Scholar
Sala, O. E. & Lauenroth, W. K. (1982). Small rain events: an ecological role in semi-arid regions. Oecologia 53, 301–304.CrossRefGoogle Scholar
Sala, O. E., Parton, W. J., Joyce, L. A. & Lauenroth, W. K. (1988). Primary production of the central grassland region of the United States. Ecology 69, 40–45.CrossRefGoogle Scholar
Seastedt, T. R., Briggs, J. M. & Gibson, D. J. (1991). Controls on nitrogen limitation in tallgrass prairie. Oecologia 87, 72–79.CrossRefGoogle ScholarPubMed
Shaw, M. R., Zavaleta, E. S., Chiariello, N. R., Cleland, E. E., Mooney, H. A. & Field, C. B. (2002). Grassland responses to global environmental changes suppressed by elevated CO2. Science 298, 1987–1990.CrossRefGoogle ScholarPubMed
Smith, P. & Olesen, J. E. (2010). Synergies between the mitigation of, and adaptation to, climate change in agriculture. Journal of Agricultural Science, Cambridge 148, 543–552.CrossRefGoogle Scholar
Smith, S. D., Strain, B. R. & Sharkey, T. D. (1987). Effects of CO2 enrichment on four Great Basis grasses. Functional Ecology 1, 139–143.CrossRefGoogle Scholar
Smith, S. D., Huxman, T. E., Zitzer, S. F., Charlet, T. N., Housman, D. C., Coleman, J. S., Fenstermaker, L. K., Seemann, J. R. & Nowak, R. S. (2000). Elevated CO2 increases productivity and invasive species success in an arid ecosytem. Nature 408, 79–82.CrossRefGoogle Scholar
Smith, M. D., Knapp, A. K. & Collins, S. L. (2009). A framework for assessing ecosystem dynamics in response to chronic resource alterations induced by global change. Ecology 90, 3279–3289.CrossRefGoogle ScholarPubMed
Stöcklin, J., Schweizer, K. & Körner, C. (1998). Effects of elevated CO2 and phosphorus addition on productivity and community composition of intact monoliths from calcareous grassland. Oecologia 116, 50–56.Google ScholarPubMed
Suttle, K. B., Thomsen, M. A. & Power, M. E. (2007). Species interactions reverse grassland responses to changing climate. Science 315, 640–642.CrossRefGoogle ScholarPubMed
Wan, S., Hui, D., Wallace, L. & Luo, Y. (2005). Direct and indirect effects of experimental warming on ecosystem carbon processes in a tallgrass prairie. Global Biogeochemical Cycles 19, GB2014.CrossRefGoogle Scholar
Wand, S. J. E., Midgley, G. F., Jones, M. H. & Curtis, P. S. (1999). Responses of wild C4 and C3 grass (Poaceae) species to elevated atmospheric CO2 concentrations: a meta-analytic test of current theories and perceptions. Global Change Biology 5, 723–741.CrossRefGoogle Scholar
Wilsey, B. J., McNaughton, S. J. & Coleman, J. S. (1994). Will increases in atmospheric CO2 affect regrowth following grazing in C4 grasses from tropical grasslands? A test with Sporobolus kentrophyllus. Oecologia 99, 141–144.CrossRefGoogle ScholarPubMed
Wilsey, B. J., Coleman, J. S. & McNaughton, S. J. (1997). Effects of elevated CO2 and defoliation on grasses: a comparative ecosystem approach. Ecological Applications 7, 844–853.Google Scholar
Wythers, K. R., Lauenroth, W. K. & Paruelo, J. M. (1999). Bare-soil evaporation under semi-arid field conditions. Soil Science Society of America Journal 63, 1341–1349.CrossRefGoogle Scholar
Zanetti, S., Hartwig, U. A., van Kessel, C., Lüscher, A., Hebeisen, T., Frehner, M., Fischer, B. U., Hendrey, G. R., Blum, H. & Nösberger, J. (1997). Does nitrogen nutrition restrict the CO2 response of fertile grassland lacking legumes? Oecologia 112, 17–25.CrossRefGoogle ScholarPubMed
Ziska, L. H., Manalo, P. A. & Ordonez, R. A. (1996). Intraspecfic variation in the response of rice (Oryza sativa L.) to increased CO2 and temperature: growth and yield responses of 17 cultivars. Journal of Experimental Botany 47, 1353–1359.CrossRefGoogle Scholar
Ziska, L. H., Reeves, J. B. & Blank, R. R. (2005). The impact of recent increases in atmospheric CO2 on biomass production and vegetative retention of cheatgrass (Bromus tectorum): implications for fire disturbance. Global Change Biology 11, 1325–1332.CrossRefGoogle Scholar