In many areas of the world fire plays an influential role in shaping landscape structure and change. In some regions, people have used fire as a landscape management tool for thousands of years; in others a shorter history of fire exclusion has resulted in what some have characterised as a ‘socioecological pathology’. In the context of the scientific and policy debate surrounding potential climate change adaptation and mitigation strategies, here we examine how fire regimes are shifting in landscapes undergoing socioeconomic change. Specifically, we examine chestnut forest landscapes in two municipalities in central Spain – Casillas and Rozas de Puerto Real – which have similar biophysical properties but diverging economic development and fire management policies. Both municipalities are characterised by a Mediterranean-type climate and have forests dominated by chestnut (Castanea sativa Mill.). However, there are clear differences between the two municipalities in both per capita income levels (greater in Rozas) and occupational activities (greater employment in the service sector in Rozas). Furthermore, costs of fire exclusion per hectare between the landscapes differ markedly (greater in Rozas). To examine possible differences in landscape structure and fire regime between the municipalities, we conducted a dendroecological study to identify fire activity through tree scars, collected official fire statistics, and examined aerial photography. To understand traditional knowledge of fire as a management tool we conducted interviews and questionnaire surveys with local inhabitants, and examined how this knowledge corresponds to the current biophysical landscape state and recent fire activity.
Our results suggest that fire incidence in both landscapes has increased in recent decades but fire season, fire size, and forest structure have changed to a greater extent where socioeconomic and land-practice changes have been greatest. From aerial photography we found that although ‘open canopy’ forest (Figure 1a and b) has declined in both municipalities since mid-Twentieth century, with corresponding increases in the extent of ‘closed canopy’ structure (Figure 1c and d), this process seems to have taken place to a greater extent in Rozas than in Casillas. In Casillas most fires still take place in the traditional fire season (i.e. autumn and spring months) and seem to be linked to the management devoted to the production of chestnuts, firewood and other traditional management goals such as annual controlled litterfall burning next to or inside the hollow chestnut tree trunk to prevent root rot (Figure 2). In contrast, in Rozas the vast majority (71%) of fires occur in summer months, seemingly corresponding to non-traditional fire regime attributes linked to different land uses (greater abandoned shrubland in Rozas), land tenure (larger land holdings used as hunting estates) and the abandonment of traditional fire use.
