Should Forest Transition Theory include effects on forest fires? The case of Spain in the second half of the twentieth century

Abstract

This paper analyses the increase in forest surface covered by trees in Spain in the second half of the twentieth century in the light of Forest Transition Theory and explores the existence of a statistical relationship between this process and the extension of forest fires. The study describes the afforestation policy based on new forest plantations started by Franco´s regime in 1940 which surpassed the chronological limits of the dictatorship and lasted until 1988, linking it to the forest fires that occurred in the period 1968-2002. The objective is to determine, at a provincial level, the extent to which the afforestation activity affected the number of hectares burnt. The evidence shows a significant positive relationship between forest fires and the afforested hectares, especially 30-35 years after plantations. The effect increases when the model is implemented exclusively for the Cantabrian and Atlantic northwest provinces, especially affected by afforestation programmes. Our findings reinforce the need to complement certain models of Forest Transition based on tree plantations, taking into account the possible relationship that they have with fires, particularly in environmental contexts prone to fires.

Half-Century Changes in LULC and Fire in Two Iberian Inner Mountain Areas

“…We conclude that for the 1990-2000 period, when fire occurred selectively in forest in both massifs, the transition from forest to shrubland was caused largely by fire. This dynamic of forest regression supports the linkage between reforestations and fire suggested by various authors [54,114,115], because the areas burned between 1990 and 2000 were often those reforested in the previous decades. With less area of pastures and agriculture, the landscapes were fire-prone.…”

Determinants of Land Use/Cover Change in the Iberian Peninsula (1990–2012) at Municipal Level

“…Forest plantations, particularly of fast-growing species like maritime pine (Pinus pinaster) and eucalyptus (mainly Eucalyptus globulus) [40] and spontaneous encroachment (more frequent in the northeastern mountainous areas of the country) [41] have not been enough to counterbalance the effect of wildfires, although this is debated by some sources [16]. On the contrary, afforestation is one of the main processes in Spain, particularly in the more rugged, mountainous areas located at higher altitude [42], but also in areas where forest plantations coexist with high livestock density (Galicia, Basque Country, Catalonia). In the latter, a significant amount of fodder (e.g., soy and corn) is imported each year, thus freeing land that should be otherwise dedicated to fodder production for other uses, essentially forest plantation of fast-growing species [43].…”

Have Historical Land Use/Land Cover Changes Triggered a Fire Regime Shift in Central Spain?

“…Fire 2019, 2, 44 12 of 30 most complex and changeable LULC evolution of all of the case studies. Iruelas (Figure 4d) was mainly an agroforestry site in between 1890 and 1930, and forestland was reduced to a small patch in the North.…”

“…In fact, the reforestation programs of the 19th and mainly 20th century, as well as the afforestation plans subsidized by the European Union (EU) in the frame of the Common Agricultural Policy (CAP) Reform, contributed significantly to reversing the deforestation trend of the previous centuries and to consolidating the current progressive processes of forestland [42,43]. In this sense, Iriarte-Goñi & Ayuda [44] have recently provided evidence of the relationship between the forest transition processes of the second half of 20th century and the increasing fire impact between 1968 and 2002 in Spain.…”