FIRES OF HELL IN PATAGONIA
The major causes of fires in
the Patagonia, as in the rest of the world, can be roughly divided
in two groups: Those which are caused by men and
those which happen due to natural causes, as for
example by the effects of lightning in areas struck by electric
storms. The latter have only been registered in the Northern zone
of Patagonia, as in Neuquén, Río Negro, the National Park of Lanín
and in the National Park of Nahuel Huapi. It can thus be concluded
that those forest fires in Santa Cruz have to have been caused by
men, either by negligence or even intentionally.
A century ago, in the beginnings of the colonisation, this region went through some great intentional fires, with the aim of opening up new fields in which to develop cattle breeding.
Nevertheless, there is evidence that in the Patagonia these fires have been happening since at least 10.000 years ago, the point that still remains unknown is what caused them, for man had already arrived there by then. Considering all of the Patagonia, the present number of fires is originated, in 93% of the cases, by human intervention, leaving a mere 7% to climatic causes, although the latter are the most damaging, achieving 57% of the areas devastated.
Within our forests, prevention is a very important item, because the causes of fires are almost totally of human origin. The most frequent fires take place during the month of February, when the climatic conditions are favourable. These natural woods contain a very high load of fuel, around 100 tons by hectare or even more, composed by rotten wood, fallen trees, dry leaves, etc. The relative humidity of this gross material reaches the critical level of 20% after the long periods of draught which characterise the summer season in the Northern zone of Patagonia.
Not all of the fires bring the same amounts of damage, these, as is easy to conclude, have a direct relation with the intensity of the fire. The low intensity fires are produced on scarce fuelling elements or when they present some degree of humidity, so the heat do not reach and kill the roots, so the action of this kind of fire can be seen as a cleansing. Only few of the trees are affected, hence they will keep producing their seeds and the continuity or perpetuity of the forest is not endangered. Over a similar area can develop a high intensity fire provided, for example, if too much fuel has been accumulated (trunks, branches, etc.) and if it has also had time to become dry. In this case, the heat will kill the roots and the biota of the ground to variable depths, and the flames will reach the higher leaves of the trees, thus killing large numbers of them.
Unlike the common belief, the forest obtains its nourishment from a 60 centimetres thick layer of soil with medium levels of fertility. Below are other layers of different compositions, like pebbles, sand, clay, and many others, all of which are unable of sustaining most species of plants without the presence of the upper layer. Usually, this thin upper layer is fixed by the roots of the trees, but when these are burned, there is nothing else to fix these soils and they become eroded. The results can be a barren land with no capacity of regeneration in short or medium terms. While in a few years some plants and bushes can grow again in these barren fields, if there is no soil in which to fix the trees, the recovery will turn out to be a very difficult task.
After a fire, the eroding process will mainly be carried out by the action of the wind. Over the exposed hillsides with steep slopes and little developed soils, no regeneration will ever be attained because of the of top soil, which forbids the installation of new plants by the sowing of seeds.
In the case of steep slopes, the action of the water erosion will be increased along the length of it. In the areas of forest steppes a total destruction of the forests after the fires can be observed with the worsening effect brought by the use of these areas for pastures.
Depending on the distance between fires to a near forest, the regeneration could or could not be established again. From this point of view, it is very important the capacity of rebirth of the blossoms of some species as the Ñire, which is capable of this and also of growing new sprouts from its roots. In the case of the Lenga, which disperses its seeds with the help of the wind but no farther away than fifty metres from the mother tree, it is not easy that they could be able to colonise any area at more than that distance and due also to the rare occasions that it can multiply in a vegetative way, it will be justified to practise an artificial re palnting.
Fortunately, the latter is not greatly damaged by fires, partly owed to the height of its leaves.
In the Argentinean Patagonia some 100.000 hectares go up in fllames annually, of which a 7% are native forests and 90% grasslands.
Although the organisations created for the control of fires do struggle against all of them, the fires due to natural causes have always been a natural phenomenon within the ecosystem. The total elimination of fires can result in unwanted changes in the patterns of the vegetation and can also allow for the accumulation of combustible materials, increasing the possibilities of some catastrophic fires in the future. In some parks and natural reserves, where the goal is to maintain the natural conditions, the fires occasioned by lightning are usually let to follow their own course under a meticulous surveillance.
Nature does not stand dauntless in the presence of fire. It has its own mechanisms for recovering, but it needs to be left untouched as much as possible. In many cases it is not necessary to intervene in any way. The recovery gets started as soon as the fire is extinguished. But in the cases where the damage is very bad it may require human intervention in order of reconstructing what men itself has destroyed. This needs to be taken with caution, for sometimes it is worst to make a bad recovery job than to let things be as they are.
The forest fires are occasioned by human neglect and so it is up to us who must try and find a solution to the problem, developing a system that permits its location before they can grow out of control.
All these catastrophes are obviously impossible to avoid although foreseeable indeed. In the particular case of the forest fires of timely recurrence on every summer season, THEY ARE VERY FORESEEABLE. Thanks to some modern techniques of satellite observation and follow up, we can process with the help of computers precise forecasts concerning the behaviour and intensity of devastating phenomenon which with a smart plan of prevention can diminish its heinous effects.
We are the ones to whom, between January and February every year is left the task of regretting the disappearance of millions of specimens of irretrievable species.