Fire-Vegetation-Climate linkages in Patagonia since Late Glacial times through Pollen and Charcoal Records of Lake Sediments.

BIANCHI, M.M.; WHITLOCK, C.; IGLESIAS, V.; NAVARRO, D.; QUINTANA, F.

Puerto Madryn

Simposio; 5th Fire Paradox Plenary Meeting & Primer Simposio Sudamericano sobre Ecología y Manejo del Fuego.; 2009

Centro de Investigación y Extensión Forestal Andino Patagónico (CIEFAP)

Fire is a critical Earth-system process, with broad impacts on atmospheric and biogeochemical processes, and in regulating ecosystem dynamics and composition. In Patagonia, fire is an important natural disturbance, shaping vegetation composition and landscape structure, as well as a critical link between vegetation and climate change. Its occurrence is determined by ignition probability and fuel desiccation, availability, and continuity, which, in turn, results from complex interactions between the climate and vegetation of the area. The relative influence of governing mechanisms of fire regimes are expected to vary across scales in specific ways. On centennial to orbital time scales, changes in climate alter key properties of regional fire regimes and vegetation composition. On shorter time scales, climate-weather and vegetation characteristics affect the fire conditions of particular years as well as the dynamics of post-fire ecological succession. For example, inter-annual climatic variations associated with atmosphere-ocean interactions favour fire occurrence in fuel limited ecosystems, whereas slow climate variations over thousand years determine the replacement of plant communities and their fire regimes. Human activities (past, present and future) also affect fire linkages with vegetation and climate. Therefore, the importance of anthropogenic burning must be carefully evaluated at all temporal and spatial scales.