Continuing on the subject of our wild Guadarrama pines (known as Scots Pine in Angloamerika), there is some debate as to what exactly is the natural range of this tree in the Central System of mountains – and more specifically in the Sierra de Guadarrama – and the influence of reforestation on this range. According to one authoritative school of thought Pinus sylvestris would grow naturally above 1600-1700m; below this altitude would be the realm of the so-called Pyrenean Oak (Quercus pyrenaica, locally known as rebollo or melojo). Others argue that the pines of Guadarrama have always extended down to 1200-1300m, mixing with the oaks at this altitude – as is the current distribution. Those who believe that the pines should be present only above 1600m generally point to the hand of man and his forestry techniques as responsible for the unnatural extension of P. sylvestris and here emerges the argument that the resulting artificial masses of pine forest are particularly vulnerable to forest fires.
What seems to be clear is that certain areas of the Sierra had become seriously deforested by the late 19th century, due among other factors to foraging cattle, sheep and goats, and that some of these areas were reforested during the 20th century. There is no doubt that the forestry departments responsible for this replanting predominantly favoured pines over other species. However there is also strong evidence that some areas –particularly Valsaín– have, over the last four to five centuries, maintained extensive pine forests down to 1200-1300m. And that specifically Valsaín has historically suffered forest fires, long before the advent of mechanized forestry operations or modern forestry management techniques.
Another fundamental question that requires consideration is that of what a natural Pinus sylvestris forest would look like. It is clear that P. sylvestris cannot naturally constitute forest masses that are both extensive and dense. This species cannot reproduce in such contexts i.e. “under its own canopy”. Young P. sylvestris trees will not prosper in shady conditions. This would seem to indicate that the masses of Fuenfría, El Espinar, Valsaín, etc are at least not entirely natural and require some kind of selective logging and probably extensive fire prevention measures in order to be sustainable.
My suspicion is that, regardless of whether the pines are natural down to 1200-1300m (and they may well be), our Guadarrama pine forests – to which i have to say i am profoundly attached – are to some degree artificial in their current presentation either due to over-enthusiastic replanting of clearings by forestry departments or their favouring the pine to the detriment of other species. And yes, the resulting extensive, dense masses of wild pines probably are more susceptible to extensive and potentially devastating fires than a more natural forest would be.
I guess that’s always the story with artificial paradises..what can you do?
Live and hope.. !
 This line of thought is represented by Salvador Rivas-Martínez et al, “Piornales, Enebrales y Pinares oromediterráneos en el Sistema Central” 1987, among other publications.
 A paper by Felipe Martínez García (2001) which presents this argument: http://www.um.es/analesdebiologia/numeros/24/PDF/04-QUE%20VALOR%20TIENE.pdf
 For a discussion of this question look here: http://www.sistemacentral.net/foro/viewtopic.php?t=11261
 Consult early photographs of the Sierra. Easily identifiable areas such as the lower Fuenfría valley or around Cotos are dramatically different to what they look like today.
 See sections 3,4 and 5 of this 2008 paper by Carlos Manuel Valdés: http://www.magrama.gob.es/es/ceneam/recursos/documentos/propiedad_uso_gestion_tcm7-13559.pdf