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Les taux de CO2 élevés augmentent la productivité et la survie des espèces envahissantes dans un écosystème aride.

Elevated CO2 increases productivity and invasive species' success in an arid ecosystem.

Auteurs : SMITH S. D., HUXMAN T. E., ZITZER S. F., et al.

Type d'article : Article

Résumé

Arid ecosystems, which occupy about 20% of the earth's terrestrial surface area, have been predicted to be one of the most responsive ecosystem types to elevated atmospheric CO2 and associated global climate change. The authors show, using free-air CO2 enrichment (FACE) technology in an intact Mojave Desert ecosystem, that new shoot production of a dominant perennial shrub is doubled by a 50% increase in atmospheric CO2 concentration in a high rainfall year. However, elevated CO2 does not enhance production in a drought year. The authors also found that above-ground production and seed rain of an invasive annual grass increases more at elevated CO2 than in several species of natives' annuals. Consequently, elevated CO2 might enhance the long-term success and dominance of exotic annual grasses in the region. This shift in species composition in favour of exotic annual grasses, driven by global change, has the potential to accelerate the fire cycle, reduce biodiversity and alter ecosystem function in the deserts of western North America.

Détails

  • Titre original : Elevated CO2 increases productivity and invasive species' success in an arid ecosystem.
  • Identifiant de la fiche : 2002-0522
  • Langues : Anglais
  • Sujet : Environnement, Généralités
  • Source : Nature - vol. 408 - n. 6808
  • Date d'édition : 02/11/2000
  • Document disponible en consultation à la bibliothèque du siège de l'IIF uniquement.

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