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Introduction

  • J. Nösberger
  • S. P. Long
Part of the Ecological Studies book series (ECOLSTUD, volume 187)

1.6 Conclusions

  • Managed ecosystems cover the greater part of the global land area and have the greatest potential to alter [CO2]. They facilitate the use of manipulable variables and help to detect new insights into the effects of e[CO2] on plant growth, development and processes in the soil.

  • FACE studies now provide our most realistic estimates of how ecosystems in the open will respond to the atmospheric [CO2] predicted for the middle or end of this century. They are our best validation data for models predicting the responses of managed ecosystems and natural vegetation to this ongoing change. Production changes and other effects due to elevated [CO2] in FACE differ significantly from observations made in chamber and greenhouse studies, suggesting that responses are signigicantly modified in protected environments and that models parameterized from such data might be in serious error.

  • Elevated [CO2] affects ecosystem processes via a multitude of mechanisms at different timescales. The relationships between the C and N metabolism in the plants and the N availability in the soil are key factors that influence the direction and magnitude of the response of ecosystems to a [CO2]-enriched atmosphere.

  • Projections of ecosystem responses to elevated [CO2] must incorporate the reality of multiple factor influences. Many suggestions in this volume guide to the development of testable hypotheses for experiments which could provide basic information for predictive computational models. The findings have important implications for public policy decisions and adaptations of management systems.

Keywords

Leaf Photosynthesis Global Change Biol Plant Stand World Resource Institute Soil Organic Carbon Sequestration 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Ainsworth EA, Long SP (2005) What have we learned from 15 years of free-air CO2 enrichment (FACE)? A meta-analytic review of the responses of photosynthesis, canopy. New Phytol 165:351–371PubMedCrossRefGoogle Scholar
  2. Ainsworth EA, Davey PA, Hymus GJ, Osborne CP, Rogers A, Blum H, Nösberger J, Long SP (2003) Is stimulation of leaf photosynthesis by elevated carbon dioxide concentration maintained in the long term? A test with Lolium perenne grown for 10 years at two nitrogen fertilization levels under free air CO2 enrichment (FACE). Plant Cell Environ 26: 705–714CrossRefGoogle Scholar
  3. Dermody O, Long SP, DeLucia EH (2006) How does elevated CO2 or ozone affect leaf-area index of soybean when applied independently? New Phytol 169:145–155PubMedCrossRefGoogle Scholar
  4. FAO (2002) FAO-STAT statistics database. UN Food and Agriculture Organization, RomeGoogle Scholar
  5. Gifford RM (1994) The global carbon cycle: a viewpoint on the missing sink. Aus J Plant Phys 21:1–15CrossRefGoogle Scholar
  6. IPCC (2001a) Climate change 2001: impacts, adaptation and vulnerability. Cambridge University Press, CambridgeGoogle Scholar
  7. IPCC (2001b) Climate change 2001: the scientific basis. Cambridge University Press, CambridgeGoogle Scholar
  8. Lal R (2003) Global potential of soil carbon sequestration to mitigate the greenhouse effect. Crit Rev Plant Sci 22:151–184Google Scholar
  9. Leakey ADB, Uribelarrea M, Ainsworth EA, Naidu SL, Rogers A, Ort DR, Long SP (2006) Photosynthesis, productivity, and yield of maize are not affected by open-air elevation of CO2 concentration in the absence of drought. Plant Physiol 140:779–790PubMedCrossRefGoogle Scholar
  10. Li SG, Asanuma J, Eugster W, Kotani A, Liu JJ, Urano T, Oikawa T, Davaa G, Oyunbaatar D, Sugita M, (2005) Net ecosystem carbon dioxide exchange over grazed steppe in central Mongolia. Global Change Biol 11:1941–1955CrossRefGoogle Scholar
  11. Li SG, Eugster W, Asanuma J, Kotani A, Davaa G, Oyunbaatar D, Sugita M (2006) Energy partitioning and its biophysical controls above a grazing steppe in central Mongolia. Agric For Meteorol 137:89–106CrossRefGoogle Scholar
  12. Long SP, Ainsworth EA, Leaky ADB, Morgan PB (2005) Global food insecurity. Treatment of major food crops with elevated carbon dioxide or ozone under large-scale fully open-air conditions suggests recent models may have overestimated future yields. Phil Trans R Soc B 360:2011–2020PubMedCrossRefGoogle Scholar
  13. Morgan PB, Bollero GA, Nelson RL, Dohleman FG, Long SP (2005) Smaller than predicted increase in aboveground net primary production and yield of field-grown soybean under fully open-air [CO2] elevation. Global Change Biol 11:1856–1865CrossRefGoogle Scholar
  14. Nowak RS, Ellsworth DS, Smith SD (2004) Functional responses of plants to elevated atmospheric CO2 — do photosynthetic productivity data from FACE experiments support early predictions? New Phytol 162:253–280CrossRefGoogle Scholar
  15. Schneider MK, Lüscher A, Richter M, Aeschlimann U, Hartwig UA, Blum H, Frossard E, Nösberger J (2004) Ten years of free-air CO2 enrichment altered the mobilization of N from soil in Lolium perenne L. swards. Global Change Biol 10:377–388CrossRefGoogle Scholar
  16. Van Kessel C, Boots B, Graaf M de, Harris D, Blum H, Six J (2006) Soil C and N sequestration in a grassland following 10 years of free air CO2 enrichment. Global Change Biol (in press)Google Scholar
  17. White R, Murray S, Rohweder M (2000) Pilot analysis of global ecosystems: grassland ecosystems. World Resources Institute, Washington, D.C. World Resources Institute (2002) World resources 2000–2001: people and ecosystems: the fraying web of life. United Nations Development Programme, United Nations Environment Programme, World Bank, World Resources Institute, Washington, D.C.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • J. Nösberger
    • 1
  • S. P. Long
    • 2
  1. 1.Institute of Plant SciencesETHZurichSwitzerland
  2. 2.Department of Plant BiologyUniversity of IllinoisUrbanaUSA

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