INVESTIGADORES
PARITSIS Juan
congresos y reuniones científicas
Título:
Synergistic Influences of Climate Variability and Human Impact on Wildfire Activity in Southwestern South America
Autor/es:
A HOLZ; J PARITSIS; TT VEBLEN
Lugar:
Seattle
Reunión:
Congreso; 56th AAG Annual Meeting; 2011
Institución organizadora:
Association of American Geographers
Resumen:
Before long-lasting changes are evident, ecosystems may be committed to significant changes in relation to climate forcing interacting with trends in land use. Variability in wildfire activity and the ecological effects of land-use changes along a gradient from Patagonian rainforests to the ecotone of forests and woodlands with the Patagonian steppe in temperate southwestern South America are analyzed in the context of climate variability associated with the Southern Annular Mode (SAM). We explore how wildfires may promote the existence of feedbacks in vegetation flammability in Nothofagus woodlands and forests. We demonstrate the strong role that variability in SAM at interannual and decadal scales has on wildfire activity in the region. Furthermore, the use of fire by European settlers to clear forests for agriculture and to facilitate timber extraction significantly increased burning in the region. Climate variability related to SAM and decadal-scale changes in land-use have been the main drivers of wildfire activity in the region. Preliminary analyses of post-fire vegetation transitions indicate a failure of tree regeneration and replacement of fire-resistant tall forests by more flammable second growth vegetation dominated by resprouting shrubs and small trees which in turn implies a positive feedback towards a more fire-prone landscape. In the future, it is likely that these ecosystems will become more susceptible to fire associated with predicted upward SAM and warming/drying trends in temperate southwestern South America.