In the summer of 2021, enormous wildfires in the Mediterranean eliminated huge areas of mainly coniferous forest, destroyed adjacent settlements and claimed the lives of many people. The fires indicate effects of climate change and expose consequences of rural demographic changes, deficits in regional and touristic development planning and shortcomings in forest policy. This forum article highlights the dimensions of the problem, calls for a paradigm shift and shows solutions. Land abandonment, woody plant encroachment and non-reflective afforestation are leading to increasing amounts of combustible biomass. To prevent disastrous fires in future, fundamental changes in tree species composition, forest structure and management are essential. Plantations of reseeding pines are to be substituted by spacious or periodically open woodlands of long-lived trees with resprouting capacity such as Mediterranean oaks. Biomass-reducing practices including wood-pasture have to be revived in rural and peri-urban areas. Exemplary fire-resistant multifunctional oak woodlands occur throughout the Mediterranean. Urgent and medium-term measures in the burnt areas include promoting natural ecosystem regeneration, developing regionalized seed banks and nurseries to support native genetic resources, fostering vegetation mosaics of groves and multiple-use open and coppice woodland maintained by traditional practices, and in general forest management aiming at fuel biomass reduction and a policy counteracting land abandonment.

biomass reduction, fire prevention, forest fire, forest management, Mediterranean Basin, oak, pine forest, wood pasture

In recent years Mediterranean-type climate regions (Walter 1979; Schroeder 1998; Rivas-Martinez et al. 2011) have frequently and in ever greater degree been hit by disastrous wildfires (Le Houerou 1993; Pausas 2004; Syphard et al. 2009; Sarris et al. 2014). In this year’s summer of 2021, many countries of the Mediterranean Basin were severely affected, especially southern and western Turkey, southern and central Greece, southern Italy, Algeria, Spain, and southern France (EFFIS 2021). The fires came with tremendous heat waves, they destroyed forests, fields, equipment, houses and settlements, and they took many human lives. In central Greece alone the burnt area comprised about 130,000 ha. In the Turkish region of Manavgat, a single fire, unprecedented in the history of the country, devastated 60,000 ha. In Italy, this year more than 140,000 ha have been in flames, equalling the catastrophic record of 2017. In that year 2017, in June, a wildfire in pine forests in Central Portugal killed 66 people and burnt nearly 500 houses. People everywhere realized, many perhaps for the first time, that in Mediterranean forest landscapes, pre-shaped by land abandonment and land-use change, climate change constitutes a real and immediate threat, not merely a theoretical one.

Wildfires are often caused by arson, even more commonly are they initiated through carelessness. They happen mostly in the periods of drought, which are a characteristic of the Mediterranean summer. As a consequence of climate change and water overuse, the Mediterranean experiences increasing drought, springs dry up and seasonal streams carry less and less water and run dry earlier in the season (Körner et al. 2005). Climate change scenarios indicate rising temperatures and decreasing amounts of precipitation and as a result, longer summer aridity, soil water shortages and increasing fire risk (Mouillot et al. 2002; Moriondo et al. 2006; Lozano et al. 2017; IPCC 2021). Moreover, it has become apparent that through climate change fires shift towards higher altitudes, thereby increasing the hazard in forest ecosystems not well adapted to fires (Koutsias et al. 2012).

Land abandonment, a process that is taking place in much of the Mediterranean Basin chiefly after the mid-20th century, contributes to the increased fire hazard (Le Houerou 1993; Plieninger et al. 2016). As a result of decreasing populations inhabiting rural areas accompanied by a decrease of pasture and arable lands, land abandonment is often associated with an increase of forest and scrub cover and overall with an accumulation of biomass that fuels potential wildfires (Mantero et al. 2020). Formerly, farmland and open grazing land around the villages comprised a fire-resisting zone and prevented the flames from spreading to the houses. In mountainous regions the previously higher number of inhabitants in villages, the closer relationship of the rural population with nature (many of them were farmers and animal breeders) formed a body of volunteers capable of fighting a fire to protect their properties.

In general, burns in forested and shrubby landscapes are not uncommon in regions of Mediterranean-type climate and there is a long history of evolutionary adaptation of plants and ecosystems to fire (Naveh 1975; Margaris 1981; Bond and van Wilgen 1996; Ne’eman et al. 2012; Rundel et al. 2018). Many plant species have adapted to more or less tolerate fires by morphological and life history traits (Ne’eman et al. 2012). Ecosystems as a whole are able to cope with recurrent fires by their successional dynamics, resilience and regeneration capacities (Trabaud 1994). Even though adaptations to fire are more common or diverse in some other regions of Mediterranean-type climate, such as Southwest Australia and South Africa (Bowen and Pate 1993; Pignatti et al. 2002; Brown et al. 2003), than in the Mediterranean Basin, there are numerous examples in the Mediterranean flora interpreted as adaptations generally to disturbances or more specifically to fire (Pignatti et al. 2002; Guarino et al. 2006). Well-known examples of such pyrophytes are the cork oak (Quercus suber) with its thick bark (Pausas 1997), the fire-induced dispersion of seeds from bursting pine cones (Thanos and Dousi 2000), some pyrophile Cistaceae with seeds germinating if triggered by the heat and smoke of fire (Thanos and Georghiou 1988; Aronne and Mazzoleni 1989), many woody plants resprouting from basal or below-ground buds (Mazzoleni 1994), and in a passive way the short life-cycle of many herbaceous plants. The high proportion of annual plants, alive only in late-winter and spring, in the native Mediterranean flora is as such instructive for the degree of adaptation of the vegetation to various kinds of disturbance including fire (Bergmeier 1998; Pignatti et al. 2002; Guarino 2006).

While pine forests in Mediterranean landscapes can cope with moderate fires or even benefit from them through the destruction of potentially competitive plants, they are severely hit by intense and frequently recurrent fires destroying not only the undergrowth but the pine stems and crowns altogether (Tapias et al. 2004). Mediterranean pines are fire-adapted reseeders which have evolved adaptations to fire in that the post-fire habitat is optimized for the germination of their seeds. Post-fire regeneration of natural stands of pine forests depends on various factors (Kavgacı et al. 2010). Site physiography and soil properties play an important role in regeneration success but stand age and the persistence of scattered unburned trees, or groups of trees, that can act as source of seeds are also relevant (Kavgacı et al. 2016). Pine stands of high naturalness tend to regenerate easily after wildfires and generally there is no need for external input for their restoration.

Wildfires become catastrophic if the forests adjoin to houses, villages and suburbs, the more so in areas of urban sprawl in what had formerly been rural landscapes. Many coniferous forests in such areas are plantations or established as secondary growth originating from plantations (Tapias et al. 2004; Maiullari et al. 2005). Fast-growing pines, cypresses and eucalypts predominate. They are particularly prone to fire if they form thick stands, generate dense undergrowth with high amounts of dead biomass and thick layers of litter. It was chiefly for silvicultural or ornamental reasons and to increase the proportion of forested area in otherwise non-forested lowland environments that led to many of the coniferous plantations in the Mediterranean Basin (including Tyrrhenian coastland Pinus pinea stands which, in spite of their partly anthropogenic status, are often considered to represent autochthonous 2270* habitats of the EU Habitats Directive 92/43/EU throughout.) A landscaping design commonly used on slopes arranged the pine plants at a regular distance of 60-80 cm between each other on narrow steps of 2-5 m distance along the contour lines. On average, the initial tree density of these plantations was between 2,500 and 3,000 plants per hectare (Ciancio 2014), in Turkey 1600 seedlings at 3 x 2 m distance. After years of dead phytomass and litter accumulation they are particularly flammable and fires spread rapidly if the combustible pine bark, needles, twigs and cones cause crown fires when blown up and hurled away under the influence of strong wind and heat. A comparable case is that of the Eucalyptus globulus or E. camaldulensis plantations which cover immense areas especially in the western Iberian Peninsula as well as south and central Italy (Fernandes et al. 2019). As to their richness in flammable aromatic compounds, bark pieces flying off many metres when burned, and the accumulation of dry fine litter, we consider eucalypt plantations, in all, ecologically analogous in terms of fire to conifer stands. Around settlements, such forests are highly dangerous firetraps.

High stand densities, thick understory namely of ericoids, genistoids and cistuses, and litter accumulation are the result of management absence and policy failure. Formerly, especially in more humid areas of the western Mediterranean, heath and gorse in pine forests were regularly removed, for use as cattle bed and further incorporated in the soil as organic fertilizer. Socio-economic changes in rural territories and intensification of agriculture put an end to such traditional practices. Moreover, forms of prescribed fire existed, mostly promoted by shepherds to feed the animals with resprouting shoots. Rural exodus mainly in the 1960s to 80s facilitated land use change from agriculture and animal grazing to large stretches of monotonous forests. In recent years, land use changes were due to macroeconomic reasons, absent land ownership and misplaced state policies that lead to chronical absence of effective forest management (e.g., De Rossi 2018). Adding to the decline of traditional biomass-reducing practices, an insufficient wildfire prevention policy allowed the accumulation of forest biomass and litter on an unprecedented scale. Often, the absence of territorial policies promoting discontinuous and mosaic-diverse rural landscapes is making Mediterranean lowland forest areas prone to an accident waiting to happen.

Land-use diversification, as general principle, is a key element to effectively avoid catastrophic fires and severe climate-related disturbances (Lloret et al. 2002). As the above statements on the current situation of the lowland Mediterranean forests suggest, policymakers and forestry have an obligation to society to encourage the maintenance or restoration of land-use mosaics and multiple-use forests—as opposed to extensive tree monocultures. As J.R. Goldammer, head of Global Fire Monitoring Center, put it, “to stop the increasing threat of wildfires [in southern Europe] we’ll have to focus our efforts on stopping rural flight” and to make it a priority “to increase a woodland’s resilience against drought, strong winds and heavy rainfall” (Deutsche Welle 2021). Economic incentives to assure rural livelihoods and to support local-scale production (including but not restricted to wood, field crops, meat, cheese, game and honey) are needed to counteract land abandonment and migration from the land.

To reduce the forest fire risk and to avoid fire events to become catastrophic, the questions arise what to do with the vast burnt areas and how to improve the fire safety of the highly flammable extant Mediterranean lowland forests. To answer the questions different aspects must be taken into account—tree species composition, forest structure and forest management.

Such paradigmatic change involves moving ‘back to the future’ towards grazed wooded oak parklands and multiple-use mixed deciduous woodlands as relevant pieces of the novel Mediterranean landscape mosaic. The replacement of large stretches of dense forests of site-maladjusted conifers – or eucalypts – under intensive silviculture is mandatory to break the cycle of biomass accumulation – wildfire – biomass accumulation and so on. The preference of wooded structures, including both grazed or coppiced oak groves and well-integrated small oak mixed woodlands over monotonous pine and eucalypt plantations, would contribute greatly to ecological, social and ecological rural territory amelioration and to high resilience to wildfires (Varela et al. 2014, 2018). To summarize our appeal the following response and precautionary measures and aims are suggested:

As a prerequisite of measures in response to the devastating fires an assessment and accurate delineation of the burnt areas and fire scars and the affected plant communities is essential to determine the rates of ecosystem recovery and regeneration success. Natural regeneration is to be promoted and when necessary, seeding or planting should be performed with material collected locally from indigenous populations.

Woodlands of native tree species for multipurpose use as substitute for plantations with pines or exotic species. Various native oak species are exemplary trees in the Mediterranean lowlands. Species should be selected from the local species pool, considering also the vegetation history of the area which may involve species now absent. Special care requires the selection of genetic resources so as to form genetically diverse well-adapted tree populations of local origin.

Promoting a vegetation mosaic of groves, structurally diverse cropland, coppice woods and half-open land developed and maintained as wood pasture. This can be achieved by means of silvicultural treatments taking account of the diversity of local ecological factors (i.e., soil, relief) and aiming to differentiated genetic, structural, compositional and functional diversity at the plant population, community and landscape level. Such vegetation mosaics prevent the spread of fires and at the same time enhance biodiversity.

Development of regionalized seed banks and nurseries for the tree species of Mediterranean woodlands to conserve the species’ genetic variability and to make them available for local-scale restoration purposes whenever needed.

Elaboration of a woodland management plan that includes fire prevention (Varela et al. 2018). Forest management aiming at the reduction of fuel biomass and the promotion of traditional practices is to be encouraged. Motivations against land abandonment including a reasonable agriculture and agro-tourist policy as well as the enhancement of multiple local-scale forest use are of the utmost importance.

E.B. wrote the first paper draft and discussed the topic with all authors. All authors contributed to and commented on the final paper version.