Live fuel moisture content and leaf ignition of forest species in Andean Patagonia, Argentina

Abstract

Wildfires are common from summer to early fall in Patagonian forests of Argentina. Live fuel moisture content (LFMC) and leaf ignition are important factors for understanding fire behaviour. In this study, we determined seasonal LFMC and leaf ignition of some key fire-prone species of these forests, and their relationships with environmental variables. Species investigated were the native trees ñire (Nothofagus antarctica) and cypress (Austrocedrus chilensis), the understorey tree-like radal (Lomatia hirsuta) and laura (Schinus patagonicus), the bamboo caña colihue (Chusquea culeou), and the non-native black poplar (Populus nigra). LFMC differed among species, with caña colihue having lower values (LFMC <100%); ñire, laura, cypress, and radal having medium values (110–220%); and black poplar, upper values (>220%). Ignition characteristics differed among species (caña colihue > ñire > radal > cypress > laura > black poplar) and were inversely related to LFMC. Correlations between LFMC and environmental variables were highly significant for caña colihue, significant for ñire, radal, and laura, and weakly significant or non-significant for cypress and black poplar. These results contribute to our understanding of fire behaviour, and validate the fuel typology for Patagonian forests. At the same time, they add some useful knowledge for comparison with other fire-prone Mediterranean ecosystems around the world.