Moderate weather conditions and unusual heavy summer rains in the southern regions of Italy, in two consecutive years, were partly responsible for relatively good wildfire seasons in 1995 and 1996. After the “annus horribilis” in 1993, when the country experienced dramatic fire events, surely the worst within the last 25 years, with more than 15,000 fires and 116,000 hectares burned, the number of fires and burnt surface dropped below average figures starting from 1994, apparently stopping the increasing trend (Fig.1a,1b). In any case, the number of reported fires has significantly decreased in the modern period, while the approximate timing of improved fire-fighting technology corresponds with this decrease. The decreasing turn continues showing a decrease in the number of fires and burnt surfaces in the past few years resulted in comparison with previous years’ means (1970-1982 and 1970/92).
The distribution pattern of fires on the national territory exhibits a strong concentration of events in the southern and insular regions: though accounting only for 30.4% of the forested area of the whole country, in the past years they had more than 60% of fires and 70% of surfaces burned.
Years with a reduced number of fires are actually characterized by a moderate number of events in these areas, where figures can drop below the previous mean. Table 1 shows a trend of the concentration of fires in the three groups of regions (northern, central, southern and islands). The total budget is strongly influenced by southern regions, with a typical Mediterranean climate and a sharp summer distribution of fires.
Another feature of the phenomenon always observed in Italy, to such an extent as to be considered something of a postulate, is the high number of fires and surfaces burned in regions where forestry rates (percentage of total surface covered by forests) are strongly below national averages; the most severe situations are found in the islands of Sicilia and Sardegna, where fire is a traditional tool of rangeland management, dating from prehistoric ages. Table 2 shows fire data distribution within the regions for the past few years.
It can be observed that regions with reduced surface cover, normally accounting for the most severe budgets of events, correspond to the same southern regions and islands as mentioned above: the small group of regions (Puglia, Calabria, Campania, Sicilia, Sardegna) where summer fires are mainly voluntary and where forests can be considered marginal lands.
Fires are present, to a considerable degree, even in some central and northern regions (Lazio, Toscana and Liguria), far from marginal conditions. As a matter of fact, in these regions abandoned agricultural lands are quite often occupied by shepherds, emigrating with their flocks from Sardegna, where a shortage of rangelands is becoming a serious problem in relation to the increasing number of sheep, which still represent one of the pillars of local economy.
Fires in the northern regions of Italy are, on the contrary, without the character of the severity of the southern group; in this case fires, often winter fires, are mainly non-voluntary, often related to dry winters and large amounts of cured fuels, and though their number can be considerable, surfaces are normally rather reduced.
To conclude, the moderate budget of fires in the last two years has been interpreted, by some state agencies, as the result of the increased airplane fleet which now consists of 14 airplanes (11 of which are Canadairs) and 32 helicopters managed by the national Civil Defence Service. A reduced number of airplanes and helicopters is also used by the Regions. The airplanes are used on the basis of action on demand for every fire, with a screening procedure which forcedly always gives priority to actions in the southern regions with a Mediterranean climatic pattern, where the number of events is very high. The airplanes are operation-based from two airports in central Italy (Roma and Pisa) with the exception of some Canadairs which are seasonally attached in Sardegna and Calabria.
A considerable distance between airports and places of action therefore often results in long, wasted periods of time while on the move to the fire site, thereby obviously reducing the efficiency of water or fire-bombing, made long after the fires have begun.
Tab.1. Number of fires and burned surfaces as a percentage of the national total (1961-1996)
Tab.2. Fire number and burned areas in Italy
It is true that two years with a scarce presence of fires is likely related to weather fluctuations, but were misinterpreted in terms of the efficiency of a defense system which is still strongly based on stand-by seasonal crews; the most serious problem is that this period of unusual and unexpected calm has not been exploited to reinforce the defense apparatus in order to cope with the problem, if and when it will resume the usual size, after the odd fluctuations of the past years.
From: Vittorio Leone
Facoltà di Agraria, Università della Basilicata
I – 85100 Potenza