Wildfire Risk and Hazard in Northern Patagonia, Argentina

Abstract

Extreme wildfire events and upward trends in areas burned since the early 1980s are now well documented for many tropical and temperate forest and woodland ecosystems. Wildfire events of large extent and extreme severity are often believed to be driven either by past land-use practices that have altered fuel types (e.g. logging or fire exclusion) or by climate changes that make fuels more prone to burning, or by a combination of both. The recent trend towards increased area burned in extreme wildfires is illustrated by recent events in the mid-latitude (c. 38–43°S) Andes. In the Patagonian-Andean region of Nothofagus (southern beech trees) forests, in the late 1990s and early 2000s wildfires occurred that were more extensive and more severe than any fires in recent memory (Veblen et al. 2008). For example, in Chile during the austral summer of 2001–2002 large, severe fires burned in the region of Araucaria forests (c. 38–39°30′ S) which were believed to be the most extensive fires in this region for at least the past 50 years. Likewise, in the nearby Nahuel Huapi NP (Argentina, c. 40°S) more area burned in 1998–1999 than in any previous fire season in the 50-year documentary record (Veblen et al. 2008). Although documentary records of fire and instrumental climate records inform our understanding of changes in fire occurrence and their potential relationships to climatic variation over the past c. 100 years, assessment of the relative contributions of land-use changes and climate variation to contemporary wildfire behavior requires longer-term data for which tree-ring methods are well suited.