Fire history of Araucaria–Nothofagus forests in Villarrica National Park, Chile

• Published in: Journal of Biogeography
• Main Authors: González, Mauro E., Veblen, Thomas T., Sibold, Jason S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2005
• Subjects: Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1111/j.1365-2699.2005.01262.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2699.2005.01262.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2699.2005.01262.x

Abstract Aim In this study we examine fire history (i.e. c. 500 yr bp to present) of Araucaria – Nothofagus forests in the Andes cordillera of Chile. This is the first fire history developed from tree rings for an Araucaria – Nothofagus forest landscape. Location The fire history was determined for the Quillelhue watershed on the north side of Lanin volcano in Villarrica National Park, Chile. The long‐lived Araucaria araucana was commonly associated with Nothofagus pumilio and N. antarctica in more mesic and drier sites respectively. Methods Based on a combination of fire‐scar proxy records and forest stand ages, we reconstructed fire frequency, severity, and the spatial extent of burned areas for an c. 4000 ha study area. We used a composite fire chronology for the purpose of determining centennial‐scale changes in fire regimes and comparing the pre‐settlement (pre‐1883) and post‐settlement fire regimes. In addition, we contrasted Araucaria and Nothofagus species as fire‐scar recorders. Results In the study area, we dated a total of 144 fire‐scarred trees, representing 46 fire years from ad 1446 to the present. For the period from ad 1696 to 2000, using fire dates from Araucaria and Nothofagus species, the composite mean fire interval varied from 7 years for all fires to 62 years for widespread events (i.e. years in which ≥ 25% of recorder trees were scarred). Sensitivity to fire was different for Araucaria and Nothofagus species. More than 98% of the fires recorded by Nothofagus species occurred during the 1900s. The lack of evidence for older fire dates (pre‐1900) in Nothofagus species was due to their shorter longevity and greater susceptibility to being killed by more severe fires. Whereas the thin‐barked N. pumilio and N. antarctica are often destroyed in catastrophic fire events, large and thick‐barked Araucaria trees typically survive. The spatial extent of fires ranged from small patchy events to those that burned more than 40% of the entire landscape ( c. > 1500 ha). Main conclusions Fire is the ...