Portugal is a Mediterranean country with some Atlantic influence near the coast, strongly conditioned by physical, biological, and climatic environmental characteristics. The forest area is 3.3 million ha, and the mix of species is represented, in decreasing order, by Pinus pinaster Ait., Eucalyptus spp., Pinus pinea, Quercus suber, and with lesser representation by other coniferous and broadleaf species.
Private property is 87% of the total forest area. The size of private forest properties ranges from 2 ha in the northern part of the country to 100 ha in the south. Most of the owners, however, do not show any interest in the management of their stands, regardless of mature recently established stands. In addition to these facts, the climatic conditions of the country the precipitation in continental Portugal is ranging between 5 to 65% of potential evapotranspiration – and the low population density creates conditions for forest fires very expressive both in number and in the burnt area.
The North of Portugal is affected by a higher number of forest fires, although its contribution to the total annual burned area is small.
On the contrary it is the centre of the country, with a mean size of forest property of about 30 ha, a very high rate of forest cover and reforestation (mostly by Eucalyptus spp., and Pinus pinaster), and low population density, that most contributes to the total area burned per year, with a few large fires.
In the South of the country, the Mediterranean characteristics are very strong and the majority of the forest systems are the typical “montados” with dominant species like Quercus suber and Quercus rotundifolia in pasture lands regimes. For that reason, the number of forest fires is not yet significant.
Tab.1. Forest fire statistics for Portugal 1990-1999. Note: The data of 1998 and 1999 are preliminary.
In the next ten years, the scenario may significantly change because in addition to the extreme edaphic and climatic conditions a large-scale program of afforestation on agriculture lands has been initiated under the support of the European Community rules that aim to increase forest cover.
Fig.1. Distribution of the number of forest fires and burned surface in the last ten years
The Portuguese Forest Services has the responsibility of the management of the database on the forest fires and mapping of burned areas. Whit an average of 20 000 forest fires per year it is necessary to expeditiously develop a methodology for mapping and validation.
Since 1990 the Portuguese Forest Services in collaboration with the Forestry Department, Technical University of Lisbon (Universidade Técnica de Lisboa – UTL) is using satellite remote sensing (Landsat) imageries for mapping burned areas larger than 5 ha. This work has begun as a research project and today it is considered an operational product for mapping burned areas (Fig.2).
Fig.2. Landsat composite color image (RGB-743) with the
perimeter of the surface burned in 1998 in Vieira do Minho region.
During the fire season, major forest fires occur between June and October. At the National Co-ordination Operational Centre (CCON) the Forest Service supports a multidisciplinary team for decision making in large forest fire situations.
Since 1998 a map has been developed for strategic purposes that shows landscape features that are related to the resistance of fire propagation (scale 1:250,000). The map is available in analog and digital formats (CD-ROM). Landscape susceptibility to fire spread is expressed in three levels:
– Agriculture riparian vegetation, land burned in the last two years, urban and irrigated agricultural areas
– Brushland and rock outcrop
– Forest land and brush with high density and fuel loads
The Portuguese Forest Service whit other state departments and universities is actively engaged in research projects. A recent example of the project GEOFOGO “Simulation of Propagation of Forest Fires” (home page: http://geofogo.cnig.pt) that provides a simulation of the forest fire propagation based on the fuel and fire spread model by Rothermel, and also provides weather data and a geographic information system. This program can be used in forest management to reduce fire risk and to support decision making in fire fighting in large-fire situations. The system can be used also as a tool of information of students and to sensitize the public on forest fire behavior.
The Portuguese Forest Service is cooperating with the National Geographic Information Centre (CNIG) in the project APERTURE. This project which is supported by the European Community started in December 1997 and aims to produce remote sensing images that allow identification of land-use change after forest fires.
The Ministry of Agriculture is responsible for forest fire prevention and detection and coordinates 238 fire detection towers which cover the whole country and are operated continuously during the forest fire season. During 2000 2001 the Forest Service is testing a pilot project that explores the utilization of automatic fire detection systems, as a support to traditional systems.
The adoption of national forest management plans, with the support of advanced scientific and technical knowledge, will reduce the negative impacts of forest fires on the ecological and socio-economic systems.
Since 1999 regional forest management plans (PROF and PGF) are in place for privately owned forests.
Also in the region since 1993 the PMIF (Local Administration Service Plan for Forest Intervention) are effective which are regional plans of forest intervention whit the target to adopt some actions of forest protection, e.g. identification of areas of high fire risk, prevention needs, detection, and fire fighting mean. This plan contains the forest fire risk maps for the Local Administration Service. It also proposes forest management options including special measures for areas at high wildfire risk.
This elaboration of these plans, at Local Administration Service, allows a geo-referenced information system with supporting the actions of the management in each region for defense against the forest fires.
In the country regions where the level of forest fires is very high, these plans are very important for the Regional Forest Management Plans (Plano Regional de Ordenamento Florestal – PROF).
The participation of forest owners and their associations in forest protection is in its initial phase (since 1999) with the establishment of teams of “Sapadores Florestais” (fire guards), who work all around the year in the detection, survey, management of stands, and in support of fire suppression activities.
The problem of forest fires in the Mediterranean region is related to environmental and socio-economic factors. The defense of forest ecosystems against destructive fires must be based on inter-sectoral, cooperative and multidisciplinary approaches. Some examples have been given above. Public information on the importance of the forest and the associated space is very important. Forest fires is not a national problem but a European and global issue. Proper forest fire management is determinant in the sustainable development of forests all over the World.
Manuela Baptista and Josefa Carvalho
Direcção-Geral das Florestas
Avª João Crisóstomo, 28, 6º