Contents lists available at ScienceDirect Landscape and Urban Planning journal homepage: www.elsevier.com/locate/landurbplan Research Paper Flammability of Patagonian invaders and natives: When exotic plant species affect live fine fuel ignitability in wildland-urban interfaces Melisa Blackhall ⁎ , Estela Raffaele Laboratorio Ecotono, INIBIOMA, CONICET-Universidad Nacional del Comahue, Argentina ARTICLEINFO Keywords: Wildfires Interface vulnerability Land management Flammability traits ABSTRACT The increasing influx of people moving to woodland environments in order to access social and natural amenities is generating conflicts which are becoming ever more intense and complex. Urban-forest interface issues are currently among the most serious and problematic issues for forest managers. The wildland-urban interface has grown in size in Patagonia because of an increase in area of human settlements intermingled with natural vegetation, giving rise to a disturbing new landscape dynamic associated with wildfires. Through laboratory tests we produced the first flammability plant list for northwest Patagonia, which includes exotic species that can frequently be found in wildland-urban interface areas. We identified groups of species according to live fine fuel characteristics and detected different types of flammability, based on ignitability and heat release. Our plant list allows comparison of native and exotic species, and the formulation of precautionary action to minimize en- vironmental and economic risks. 1. Introduction In many ecosystems it is difficult to distinguish the effects of climate variation from the influence of changes in land use (Veblen et al., 2011), for example, the introduction of exotic species (for instance, through cattle browsing, exotic pine plantations). In this context, fire plays a major role in determining future landscape patterns (Gardner, Hargrove, Turner, & Romme, 1996). Changes in land use practices or the introduction of ornamental species for hedging or gardening that alter fuel conditions may change fire regimes in natural environments, as well as in the surrounding cities and towns, producing irreversible changes. This ecological damage represents considerable economic loss to human populations, and especially to the rural communities that live in these landscapes. Urban development in natural areas presents an environmental challenge in a broad sense, involving habitat fragmen- tation, introduction of invasive species into natural areas, alteration of hydrological cycles (Radeloff et al., 2005) and the creation of a new risk-prone area: the wildland-urban interface. The extension of the wildland-urban interface in Patagonia, due to an increase in area of human settlements inserted within natural ve- getation, constitutes a disturbing new landscape dynamic in relation to wildfires. Here (Bühler, de Torres Curth, & Garibaldi, 2013), as in other parts of the globe (Chas-Amil, Touza, & García-Martínez, 2013; Mercer & Prestemon, 2005), fire events over recent decades have increased in parallel with the spatial and temporal rise in human population density. For example, approximately 45% of fires recorded in the extended re- gion of Patagonia occur in the surroundings of Bariloche, the most populated city in Andean Patagonia, which is located in the conserva- tion area of Nahuel Huapi National Park (de Torres Curth, Ghermandi, & Pfister, 2008). These fires are mainly associated with a wildland- urban interface dominated by a mixture of shrublands, forests and old pine plantations. Furthermore, the number of these fires is correlated with low-income neighborhoods, thus increasing the negative social impact (de Torres Curth, Biscayart, Ghermandi, & Pfister, 2012). In addition to a low social perception of this new risk, the sprawling, disorganized expansion of these wildland-urban interfaces is likely to continue its upward trend in the region. For instance, the population growth rate of Bariloche is twofold greater than the national mean (Medina, 2017). On the other hand, climate-change models for the second half of the XXI century for the Patagonian region show trends characterized by an extension of the warmer season, and an increase in drought due to an increase in temperature and a decrease in rainfall (Holz et al., 2017). These climatic conditions, together with the in- crease in interface areas, make it necessary to obtain information on the flammability of native and introduced species growing in natural and rural environments, so as to enable prevention or reduction of interface fires in the short and medium term. Over recent years, pioneer studies in the region have explored fire dynamics in the wildland-urban https://doi.org/10.1016/j.landurbplan.2019.04.002 Received 6 August 2018; Received in revised form 28 March 2019; Accepted 6 April 2019 ⁎ Corresponding author at: Laboratorio Ecotono, Pasaje Gutierrez 1125, Bariloche 8400, Argentina. E-mail address: blackhallm@comahue-conicet.gob.ar (M. Blackhall). Landscape and Urban Planning 189 (2019) 1–10 0169-2046/ © 2019 Elsevier B.V. All rights reserved. T