CSIRO PUBLISHING Review www.publish.csiro.au/journals/ijwf International Journal of Wildland Fire 2008, 17, 713–723 Are wildfires a disaster in the Mediterranean basin? –A review Juli G. Pausas A,D , Joan Llovet A , Anselm Rodrigo B and Ramon Vallejo A,C A CEAM (Centro de Estudios Ambientales del Mediterráneo), C/ Charles R. Darwin 14, ParcTecnologic, E-46980 Paterna, Valencia, Spain. B CREAF (Centre de Recerca i Applicacions Forestals), Department of Ecology, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Spain. C Department of Plant Biology, Universitat de Barcelona, E-08028 Barcelona, Spain. D Corresponding author. Present address: CIDE, CISC, Apartado Oficial, E-46470 Albal,Valencia, Spain. Email: juli.g.pausas@uv.es Abstract. Evolutionary and paleoecological studies suggest that fires are natural in the Mediterranean basin. However, the important increase in the number of fires and area burned during the 20th century has created the perception that fires are disasters. In the present paper, we review to what extent fires are generating ecological disasters in the Mediterranean basin, in view of current fire regimes and the long-term human pressure on the landscapes. Specifically, we review studies on post-fire plant regeneration and soil losses. The review suggests that although many Mediterranean ecosystems are highly resilient to fire (shrublands and oak forest), some are fire-sensitive (e.g. pine woodlands). Observed erosion rates are, in some cases, relatively high, especially in high fire severity conditions. The sensitive ecosystems (in the sense of showing strong post-fire vegetation changes and soil losses) are mostly of human origin (e.g. extensive pine plantations in old fields). Thus, although many Mediterranean basin plants have traits to cope with fire, a large number of the ecosystems currently found in this region are strongly altered, and may suffer disasters. Post-fire disasters are not the rule, but they may be important under conditions of previous human disturbances. Additional keywords: erosion rates, Mediterranean-type ecosystems, post-fire regeneration, resilience, resprouting, soil losses. Introduction Fire plays an important role in structuring many communities worldwide (Bond et al. 2005). In the Mediterranean basin (MB), there is evidence that fires were frequent during the late Quater- nary (Carrión et al. 2003), and they were also probably frequent much earlier, as many species have acquired adaptive mecha- nisms to persist and regenerate after recurrent fires (Pausas et al. 2004a; Pausas and Verdú 2005). Even at community level, the phylogenetic biodiversity of MB plants has been sorted out as a function of the fire regime (Verdú and Pausas 2007; Pausas and Verdú 2008), that is, MB biodiversity has been structured according to the different fire regimes. Thus, it is clear that in the MB, fires are natural, they have occurred for millennia, and plants have the capacity to cope with them. In this framework, fires should not be considered an ecological disaster but rather a part of the natural process. However, some studies suggest that current fire regimes may cause disasters in the sense of induc- ing abrupt community changes (Kazanis and Arianotsou 2004; Rodrigo et al. 2004; de Luís et al. 2006; Arnan et al. 2007) or important soil losses (Marquès and Mora 1992; de Luís et al. 2005). Furthermore, wildfires introduce a high risk of direct damage to humans and structures in most of the highly popu- lated Mediterranean countries, and especially in coastal regions. Large wildfires are relatively new in the recent history of the Mediterranean basin; therefore, people see them as catastrophic events and the media amplify this perception. To evaluate the possible role of fire in generating disasters, we first need to frame MB landscapes in their historical and cultural context. One of the most striking differences between the MB and other Mediterranean-type ecosystems is its millenary history of intensive and extensive land use. In fact, current landscapes and fire regimes in the MB cannot be understood without consid- ering this millenary impact (Naveh 1975; Pausas 1999). Many cultures have evolved in the MB (e.g. Mesopotamian, Egyp- tian, Phoenician, Jewish, Greek, Arab and Roman), with many political conflicts (wars, changes in land ownership, migrations) that generated numerous socioeconomic and land-use changes. Millennia of severe pressures resulting in burning, cutting and grazing non-arable lands, and clearing (including uprooting), terracing, and cultivating arable areas have created a vast array of strongly human-modified landscapes. A large proportion of Mediterranean landscapes include terraced slopes, built for agri- cultural purposes long ago. Human-induced savannas (dehesas) and grasslands, with millenary grazing pressure by livestock, are also very important; pine plantations occur everywhere. The result of all this is that current Mediterranean landscapes are very far from being wild. In recent decades and especially on the northern (European) rim of the Mediterranean, industrialisation and rural exodus have led to the abandonment of many fields, increasing the cover and continuity of early succession species (many of which are very flammable), and changing the landscape pattern and the fire © IAWF 2008 10.1071/WF07151 1049-8001/08/060713