Every summer, forest fires are the protagonists of the great environmental dramas. Rare is the year in which several events of this type are of such magnitude that they do not end up occupying the front pages of the news, or at least they should.
In 2017, the fires in Moguer (Huelva) and Encinedo (León) devastated 7,500 and 9,800 hectares of forest area, respectively. In 2018, the Llutxtent (Valencia) fire left almost 3,500 hectares of forest area burned. In 2019, approximately 8,500 hectares in Valleseco (Las Palmas). In 2020, the year of the pandemic, more than 12,000 hectares burned in Almonaster la Real (Huelva). In 2021, the Navalacruz (Ávila) fire devastated more than 21,000 hectares, and so far in 2022, nearly 70,000 hectares have burned in two consecutive fires in the Sierra de la Culebra, which started on June 15 and in Losacio on July 17 (both in the province of Zamora).
The causes behind the forest fires
It is well known that in order to know how to prevent a problem, it is first necessary to know the causes. The causes of forest fires are usually classified into five types: natural causes (mainly lightning strikes from electrical storms), negligent or accidental causes, intentional causes, reproduction of a previous fire, and unknown causes .
Among the causes of anthropic origin, fires due to negligence or accident stand out, including those derived from bonfires or barbecues that get out of control; the passage of the railway through a susceptible area, which produces sparks due to friction, or even those caused by residues that cause fires, such as lit cigarette butts thrown on dry vegetation, or curved glass remains that act in the environment like a magnifying glass with the sunlight.
Among the intentional causes are listed, generally, the burning for agricultural or livestock purposes, the elimination of scrub and the regeneration of pastures, in addition to hunting, fishing, protests, revenge, disputes, attempts to obtain an economic benefit from some type, or pyromania.
According to a 2019 report from the then Ministry of Agriculture, Fisheries and Food, of the more than 131,000 forest fires that occurred between 2006 and 2015, only 6,448 were due to natural causes (less than 5%), to which must be added the fires caused for secondary reproductions, less than 3,000 (2%). Almost 37,000 (28%) were caused by negligence or accidents, and more than half, 69,097 (53 %) were intentionally caused . And no, neither environmental groups nor policies aimed at conserving the environment are among the causes.
The human being, behind 81% of forest fires
Even ignoring that 12% of the fires have an unknown cause —according to the same Ministry report—, it is really worrying that at least 81 % of forest fires are caused by humans . Without the anthropic cause, 880,000 of the million hectares burned between 2006 and 2015 would have been saved from the flames.
One of the pillars of fire prevention is, therefore, the awareness of society . Promoting good practices among citizens that contribute to eliminating the risk of forest fires becomes a priority. If farmers and ranchers definitively abandoned the practice of burning to “clean” fields or crops or to regenerate grass, the number of forest fires would plummet.
It is also possible to act to prevent fires due to negligence or accidents. Promote environmental hygiene, in such a way that visitors do not throw their rubbish into the natural environment, the absolute prohibition of barbecues and bonfires, and keeping the edges of roads and railways adequately clean.
Of course, it is necessary to maintain the legal consequences for the author of a fire, whether negligently or intentionally; although it is difficult to apply: on the one hand, the tougher sentences do not seem to dissuade, and on the other, although it is known that up to 81% of fires have a human origin, only in 12% can the cause be identified , and drops to 2% when the cause is intentional. This prevents the initiation of legal proceedings for the punishment of crimes, despite the fact that more than half of the fires have a clear culprit.
Preventing the fire from spreading
There are times when it is impossible to prevent a fire. In a particularly dry environment, due to the passage of a heat wave or a change in weather patterns caused by anthropogenic climate change to which the ecosystem has not yet adapted, if lightning strikes it is almost predictable, but inevitable, that a fire breaks out in the area.
The recent fire in the Sierra de la Culebra , the second largest of the 21st century in Spain, with more than 30,000 hectares devastated —the first occurred one month later, in the same area—, was caused by an electrical storm. On June 15, 2022, several lightning strikes generated up to eleven sources, which expanded rapidly due to extreme heat, very low humidity in the environment and on the ground, and gusts of wind of up to 70 kilometers per hour.
When these types of fires happen, prevention gives way to extinction . In the nomenclature of forest fires, there are three types according to their extension: the outbreaks , which extend less than one hectare, the fires themselves, which extend between one and five hundred hectares; and the great fires , which exceed five hundred hectares.
In the fight against forest fires, the idea is that all outbreaks remain in near-misses and that, as far as possible, they do not reach the proportions of large fires, and for this, extinguishing mechanisms are essential. There are certain actions that can facilitate these mechanisms.
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Mechanisms for rapid and effective action
On the one hand, the existence and maintenance of firewalls . It is not about keeping the entire forest clean of bushes —that generates a serious impact on ecosystems, which is not sustainable for flora or fauna—. It is about having corridors, strategically arranged, that delimit patches of natural vegetation. In this way, if one area catches fire, the fire is prevented from spreading to neighboring areas. In addition, these firewalls can be used as access roads for the passage of brigade vehicles.
Fire prevention actions should be in balance or, if possible, in positive synergy with other nature conservation activities, not in competition. In fact, fires produced by natural causes in well-preserved environments, with mature ecosystems, little disturbance and complete food webs, are generally self-limiting.
Having nearby bodies of water —natural or artificial— and keeping them in good condition is also a good prevention tool. The aerial means of extinguishing fires must be supplied with water, if these supply points are close and in an optimal state, the action will be faster and more efficient.
It is evident that for the firefighting brigades and services to work, they must be well maintained and constantly active, in order to act as soon as possible and with the greatest force. Early detection and immediate action are of vital importance to prevent a fire from becoming large. All this implies a political and economic commitment that, in many Autonomous Communities, does not exist.
Finally, a large part of the causes that favor forest fires are the product of anthropogenic climate change, therefore, any action aimed at mitigating them will be beneficial.
References:
Amacher, G. S. et al. 2005. Not Getting Burned: The Importance of Fire Prevention in Forest Management. Land Economics, 81(2), 284-302. DOI: 10.3368/le.81.2.284
Baeza, M. et al. 2005. Management of Mediterranean shrublands for forest fire prevention (pp. 37-60).
Lozano, F. J. et al. 2008. A multi-scale approach for modeling fire occurrence probability using satellite data and classification trees: A case study in a mountainous Mediterranean region. Remote Sensing of Environment, 112(3), 708-719. DOI: 10.1016/j.rse.2007.06.006
MAP. 2019. Forest fires in Spain: Decade 2006-2015 (NIPO: 003-19-031-5). Ministry of Agriculture, Fisheries and Food.
Martell, D. L. 2007. Forest Fire Management. En A. Weintraub et al. (Eds.), Handbook Of Operations Research In Natural Resources (pp. 489-509). Springer US. DOI: 10.1007/978-0-387-71815-6_26
