Solar UV-B radiation affects below-ground parameters in a fen ecosystem in Tierra del Fuego, Argentina: Implications of stratospheric ozone depletion

Stratospheric ozone depletion caused by the release of chlorofluorocarbons is most pronounced at high latitudes, especially in the Southern Hemisphere (including the so- called 'ozone hole'). The consequent increase in solar ultraviolet-B radiation (UV-B, 280-315 nm) reaching the earth...

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Detalles Bibliográficos
Autores: Zaller, Johann G., Caldwell, Martyn M., Flint, Stephan D., Scopel, Ana Leonor, Sala, Osvaldo Esteban, Ballare, Carlos Luis
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2002
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/152138
Acceso en línea:http://hdl.handle.net/11336/152138
Access Level:acceso abierto
Palabra clave:MYCORRHIZAL SYMBIOSIS
ROOT GROWTH
SOUTHERN HEMISPHERE
ULTRAVIOLET-B RADIATION
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:Stratospheric ozone depletion caused by the release of chlorofluorocarbons is most pronounced at high latitudes, especially in the Southern Hemisphere (including the so- called 'ozone hole'). The consequent increase in solar ultraviolet-B radiation (UV-B, 280-315 nm) reaching the earth's surface may cause a variety of alterations in terrestrial ecosystems. Most effects might be expected to occur above-ground since sunlight does not penetrate effectively below-ground. Here, we demonstrate that solar UV-B radiation in a fen in Tierra del Fuego (Argentina), where the ozone hole passes overhead several times during the Austral spring, is causing large changes of below-ground processes of this ecosystem. During the third and fourth year of a manipulative field experiment, we investigated root systems in these plots and found that when the ambient solar UV-B radiation was substantially reduced, there was a 30% increase in summer root length production and as much as a threefold decrease in already low symbiotic mycorrhizal colonization frequency of the roots compared with plots receiving near-ambient solar UV-B. There was also an apparent shift toward older age classes of roots under reduced solar UV-B. Such large changes in root system behaviour may have decided effects on competition and other ecological interactions in this ecosystem.