Dying forest of the Ore Mountains, northern Bohemia, Czech Republic
Source: Michael St Maur Sheil
INTRODUCTION |
Forest damage has long been recorded and is caused by naturalphenomena (disease and pests, storms, fire, drought and other climatic stresses) or human-induced ones (eg, air pollution, fire, economic overexploitation, overgrazing), or by the interaction of human impacts and natural causes. This chapter focuses on the two most important causes of forest degradation across Europe: air pollution, which is a serious threat to the sustainability of forest resources in Central, Eastern and, to a lesser extent, Northern Europe, and fire, which is a major concern in Southern Europe. The degradation of forest quality in the sense of its authenticity is discussed in Chapter 9, where a non-exhaustive list of remaining semi-natural forests of ecological value in Europe is given. The overall changes in species composition, age structure and management are developed in Chapter 23.
DAMAGE ATTRIBUTED TO ATMOSPHERIC POLLUTION |
Historical background |
In 1981, public attention was drawn strongly to the problem of forest degradation when the press began to report that European forests were being damaged on an unprecedented scale. These reports in the general press as well as in the scientific literature triggered a lively and often controversial debate over the causes and extent of forest damage (Blank et al, 1988). There was particular concern over the fact that the first symptoms of damage were being found on fir (Abies alba) and, later on, on Norway spruce (Picea abies) a widely distributed and commercially important species. The debate, however, was not always based on reliable information, and opinions were often characterised by preconceived ideas rather than facts. Confusion arose because, for the first time, it was speculated that air pollution was damaging trees in areas, such as Scandinavia, which were far from major pollution sources.
Forest damage is not a new phenomenon. Local problems have been reported since records began, but these were specific, resulting from definite causes, such as extreme weather conditions, insect attacks or local pollution. Unfortunately, in the early 1980s there was little knowledge about the effects of pollution on trees and the physical chemistry of forest soils in general. Furthermore, the symptoms observed the lightening of tree crowns and the loss and yellowing of needles were not characteristic of specific pollutants. It was widely accepted that acid rain, used as a synonym of air pollution in general, was the main culprit. This view dominated research on the problem and influenced political decision making for a long time; air pollution abatement legislation was introduced rapidly.
The problem |
Widespread forest damage has been reported in most Central and Eastern European countries (as well as in the northeastern USA and Canada). This has stimulated a great deal of research into its possible causes, the greatest European research contribution coming from West Germany and the Nordic countries. Many of these research projects are now almost complete. Since 1985, results have been published in reports of the German Government's Advisory Council on Forest Decline/Air pollution, in EC Air Pollution Research reports (see, eg, CEC, 1990) and elsewhere. These results have greatly improved the understanding of the problem. The definition of forest damage has been refined, and more data have become available on the geographical distribution and severity of decline.
Launching of national and transnational surveys |
Damaged tree | |
Source: Allgemeine
Forst-Zeitschrift BLV Verlagsgesellshaft |
In 1984, the West German authorities initiated annual standardised, nationwide forest damage surveys to provide a representative general account of the state of the forests. This initiative was soon adopted by other European countries. However, there were problems when comparing the results of one survey with another. In response, the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP-Forests) was established in 1985 by the Executive Body for the Convention on Long-Range Transboundary Air Pollution of UNECE. Its work was based on national monitoring inputs using conventional forest inventory methods, and was partly funded by UNEP between 1985 and 1990. Results from the national assessments are published in a series of Forest Damage Reports (see, eg, UNECE, 1991a).
A transnational EU survey was initiated under Council Regulation 86/3528/EEC. In 1987, the first survey was carried out, and in the successive years the practice was adopted by all Member States. The results of these standardised campaigns were published each year in the European Commission's forest health report (see, eg, CEC, 1989). To facilitate the comparison of forest damage surveys and national reports, a common methodology was used in accordance with the guidelines adopted by the parties to the UNECE Convention. Since 1991, the data from the UNECE and EU surveys have been published in a common annual report, Forest Condition in Europe (see, eg, CEC/UNECE, 1993). The report publishes transnational survey results from 23 European countries, based on the visual assessment of more than 90 000 trees in some 4400 standardised sampling plots defined by a uniform grid system (16 x 16 km), together with a summary of the 34 national survey results. Defoliation is based on an estimate of how much foliage has been lost compared with a reference tree, which seems to be healthy, in the same area.
Discoloration is used as a secondary indicator, which is recorded in five classes of damaged trees. The classification system introduced by the EC and UNECE defines trees as damaged once the estimated defoliation exceeds 25 per cent. The results of this type of survey (UNECE, 1991b), however, did not provide the explanation for the causal relationship between the observed damage and atmospheric pollution. Consequently, long-term observations and ecosystemic analyses on permanent plots will be carried out from 1994 onwards. (Soil and foliar analyses, deposition measurements and increment studies have been included in a sub-survey as amendment of Council Regulation 86/3528/EEC.)
Data analysis |
About 184 million hectares of forests and wooded land were investigated in the 1992 survey, covering 34 European countries (EU, EFTA, the Czech Republic, Hungary, Lithuania, Poland, Romania and the Slovak Republic). In the transnational survey of 1992, which constitutes the largest sample since 1987, 24 per cent of European trees were considered to be damaged (that is, with defoliation greater than 25 per cent). This represents an increase of 2 per cent compared with 1991. Ten per cent of trees showed discoloration. Trees most affected are characteristically older age classes. As in the previous years' surveys, the areas of highest defoliation are located in Central Europe, but defoliation is also high in certain areas of Northern and southeastern Europe (Map 34.1). The majority of highly and critically affected forests occur in Bulgaria, the Czech Republic, Germany, Poland and the Slovak Republic, where severe conifer defoliation has been recorded. Of broadleaved trees, beech (Fagus sylvatica) in Denmark and birch (Betula pubescens) in Sweden are also suffering from defoliation.
In the 1992 survey, 113 species were assessed, although the six most frequent species accounted for about two thirds of all trees. The six species are Pinus sylvestris (24 per cent), Picea abies (23 per cent), Fagus sylvatica (9 per cent), Quercus robur (4 per cent), Pinus pinaster (4 per cent) and Quercus ilex (3 per cent). On average, conifers are slightly more defoliated (24 per cent) than broadleaved trees (22 per cent), but less discoloured. Of the most common conifers found in Europe, fir (Abies spp) and spruce (Picea spp) are in the poorest condition (with 30 per cent and 26 per cent damaged trees respectively); Picea sitchensis was found to be the most damaged conifer species. Of the broadleaved trees, oak (Quercus spp) is the most damaged (24 per cent). The cork oak (Quercus suber) has the highest percentage of damaged trees of all species (33 per cent), particularly in Portugal, which may be the result of large-scale insect attacks and adverse climatic conditions, frequent forest fires, traditional landuse practices (cork exploitation) and atmospheric pollution. The holm oak (Quercus ilex) was the least damaged tree of all species.
According to the survey, defoliation seems to decrease with increasing diversity index, that is, higher defoliation is found more in monoculture than in mixed stands.
To identify the relationship between damage and climate, Europe has been subdivided into nine climatic zones (Map 34.2). Comparison of survey results has shown that defoliation of tree crowns has increased in all climatic zones except for the boreal region. The lower Mediterranean zone with the southern Atlantic and sub-Atlantic regions show forests in the worst condition. This is due particularly to the synergy between climate, management and local air pollution sources. Clear evidence of other environmental factors such as soil type and water availability on the intensity of defoliation was also shown.
The early projections (1980) suggested that forest damage would worsen and eventually destroy entire forests; so far this has not happened. Drastically defoliated and dead trees were, and are, scattered among less affected and unaffected trees, and there has been no large-scale deforestation, except in areas affected by exposure to high levels of sulphur dioxide gas in the mountainous regions of Central and Eastern Europe (Box 34A).
In order to compare results from year to year, a sub-sample of trees common to the different surveys has been studied since 1988. Since 1990 a substantial sub-sample of common sample trees (61 395 trees), which are preserved and repeatedly examined, has been established. It appears that there is a slight deterioration of the vitality of nearly all species of trees. The worsening of forest condition is happening particularly in the most damaged areas of Central Europe, but also in the Pyrenees, where no defoliation had been recorded previously.
Causes |
Improved data and advances in methods of analysis and interpretation have shown that, because of the diversity of pollutants, forests and climates, the underlying assumption that air pollutants were exclusively to blame for forest decline was too simplistic. Recent research, as reported, for example, concerning Swiss forests (Buhrer, 1993), has cast doubt on the importance of the role of atmospheric pollution on forest degradation. Also, in the south of France, for instance, the cochineal Matsucoccus feytaudi was responsible for the defoliation of about 100 000 hectares of maritime pine forest (Pinus pinaster) during the late 1980s (Marchand, 1990). Overall, the most important probable causes of defoliation and discoloration are: adverse climatic conditions, insects, fungi, forest fires, improper management, game animals living in the forest and air pollution, most probably acting in combination.
Although very little direct impact of air pollution has been reported, it is a crucial weakening factor for the forest because of the interactions with nutrient uptake, soil acidification and toxification, tree physiology, etc. This makes it particularly difficult to understand the reasons for forest decline. Presently, five hypotheses dominate research: multiple stress; soil acidification and aluminium toxicity; interaction between ozone and acid mist; magnesium deficiency; and excess nitrogen deposition, as explained below.
Economic effects |
It is difficult to predict the economic effects of forest degradation; evaluations must include not only the loss to forestry, but also the decrease in recreational value and additional costs such as the reduced prevention of soil erosion and reduced protection from avalanches. In Poland, the economic losses resulting from declining forests have been estimated to be some 60 billion zlotys per year (Nilsson et al, 1992). The economic effects of forest damage are closely linked to projections of the course of that damage. So far, fears of severe economic consequences have not been realised. There is no difference in the physical characteristics of timber from damaged and healthy trees; and although there has been an increase in the rate of unplanned salvage felling, the excess has been absorbed by the timber market.
Putting the regional differences to one side, it is important to resolve whether defoliated and healthy trees have significantly different growth patterns and, if so, to what extent growth and defoliation are correlated. The few data available show that coniferous trees grow more slowly if they lose more than 30 per cent of their foliage. This suggests a threshold rather than a linear relationship, but no reliable correlation has yet been established. These uncertainties rule out any accurate long-term projections of forest growth. Growth reductions since the 1950s or 1960s have been noted in some areas, but in other cases tree ring analysis has shown an impressive increase in growth rate during the last ten years (Becker et al, 1989). This contradictory phenomenon could be due to a good rain pattern of the past few years, combined with an increase in nitrogen deposition from the atmosphere, as for example in the Black Forest. An increase in tree growth rate does not necessarily exclude an impact of atmospheric pollution, the effects of which can be hidden. For example, nutrient excess promotes an increase in the height/roots ratio; this imbalance between above-ground (height) and below-ground (roots) development renders the trees more sensitive to wind. Nitrogen deposition on nutrient-poor sites can result in nutritional imbalance, leading to decreased yield and forest decline. In conclusion, it is most likely that atmospheric pollution in general renders trees more sensitive to any stress and diminishes their vitality. This will be all the more important as trees respond to any additional stress caused by global warming.
A model simulating forest damage due to air pollutants has been developed by the International Institute for Applied Systems Analysis (IIASA) (Nilsson et al, 1992) to predict growth losses for Western, Central and Eastern Europe. The loss of potential harvest caused by air pollutants is estimated to be about 85 million m3 per year averaged over 100 years. The regions most affected by forest decline attributed to air pollutants are the Eastern and Central regions of Europe. If, as is foreseen, Europe will face an annual roundwood deficit of some 40 million m3 per year by 2010, the deficit could amount to about 130 million m3 per year if decline caused by air pollutants is taken into account. Of course, this deficit would be partly compensated by the conversion of unused agricultural land to tree plantations, which was estimated at 8 per cent or 29 million m3 per year. This approach does not take into account the non-wood benefits of the forest and potential losses due to air pollution.
Options |
A continuation of the present pollution load for extended periods of time is expected to threaten the vitality of forests over large areas of Europe. The atmospheric concentrations and the deposition of certain pollutants in many areas exceed the levels at which disturbance to forest ecosystems would be expected. In such situations, a reduction of the air pollution load should improve the condition of endangered forests and postpone further disruption to ecosystems. Sulphur dioxide, ammonia, nitrogen oxides (as a precursor of ozone and acid deposition) and other pollutants may all be important in particular areas. Reduction of emissions in accordance with the setting up of targeted critical loads is still the first priority for action (see Chapters 4 and 31).
Conclusions |
Forest damage, as judged by European-wide surveys of tree crown condition, has increased during the last few years; however, this overall increase has not prevented some regional recovery of certain species, such as Picea abies and Pinus sylvestris. The most probable causes for the observed defoliation and discoloration have been reported to be adverse weather conditions, insects, fungi, forest fires and air pollution. Some countries, such as former Czechoslovakia, Germany and Poland, where several thousands of hectares of forests have been severely degraded, consider air pollution to be a factor leading to the weakening of forest ecosystems. However, recent research has cast doubt on the importance of the exclusive role of atmospheric pollution on forest degradation. In France, the programme DEFORPA (Dépérissement des Forêts et Pollution Atmosphérique), which was launched in 1984 to identify the causes of forest dieback and to further understanding of the effects of atmospheric pollution in general, has now been abandoned. The setting up of transnational surveys has provided a time series of large-scale spatial observations. However, they do not readily permit causeeffect relationships to be identified. In an attempt to improve the situation, a more detailed monitoring system, including the collection of information on soil, foliage, atmospheric deposition, local climate, tree growth, etc, has recently been established by the Eurpean Commission with UNECE.
DAMAGE DUE TO FIRE |
Introduction |
Research into the history of forest fires shows that fires have occurred as long as forest has existed. However, the causes of fires have changed over time. Originally, natural fires resulted from volcanic eruptions or lightning. Humans quickly made use of fire to clear and maintain land established as farmsteads and grasslands.
Today, forest fires occur for many reasons, ranging from the heritage of past agricultural practices firing land for grazing, for instance to the consequence of modern development, such as clearing land for urbanisation and tourism, and criminal action (arson).
The problem |
In Southern Europe and parts of the former USSR, fire is certainly the main problem for forest management, followed by drought and, to a lesser extent, air pollution. In Northern Europe, forest fires are sometimes used to protect heathland against tree invasion. A typical example is the management of the Lüneburger Heide in the north of Germany. In boreal forests, fire is used to maintain the diversity of the forest; enormous stands of rather pure Picea abies would develop in many areas of Sweden if burning did not occur, Pinus sylvestris, Betula pubescens and Populus tremula relying on disturbance for survival (Bradshaw and Hannon, 1992). Fire is then used as a management tool to maintain certain landscapes and ecological diversity.
The facts |
In Europe, an average of 700 000 hectares (198090) of wooded land (the term 'wooded land' is used in a broad sense it includes maquis, garrigue, heathland and even grassland from which trees have been removed) are burnt each year by a total of 60 000 fires (FAO, 1992).
Forest after fire, Portugal |
Reliable data are difficult to find for the former USSR. One estimate was that a hundred times as much forest was destroyed by fire as was planted (WWF, 1992).
Since 1990, a pilot project for the development of an information system on forest fires has been under development in the EU (Council Regulations 86/3529/EEC and 92/2158/EEC). Data have been collected daily at regional level in France, Greece, Italy, Spain and Portugal to establish a geographical database on forest fires. Some of these data are reproduced in Maps 34.3 to 34.6. In the EU, it is estimated that 35 million ha of wooded lands are at risk from fire. In 1990, there were only two days with no fires in the whole of the EU. There is a seasonal pattern which shows that, in some regions, such as in the north of Italy, most fires occur in winter and, in others, such as the north of Spain, most occur in summer (winter fires are usually less damaging than summer fires). On the other hand, some regions, such as the northwestern part of Portugal and Spain and southern Italy, which have very different climates (Atlantic/Mediterranean) and vegetation types (high forest/shrubland), show similar distribution of fires, with a peak in summer. For the Mediterranean part of the EU, two thirds of the fires occur in summer and are responsible for three quarters of the total area burnt (CEC, 1994).
Socio-economic factors seem to lead to fires in these regions, where tensions arise from conflicts between, on the one hand, agriculturalists and pastoralists who want to clear the forest to use the land for other purposes and, on the other, foresters whose aim is to maintain the land for forestry. The size of the fires also varies between these regions. The largest fires (larger than 30 ha) occur in the north of Portugal and Spain, while in the south of Italy nearly all fires are smaller than 30 ha.
More than the number, it is the size of the fires which is determinant. The important factor, however, is the total area of forest affected, and small numbers of fires are damaging large areas of forest. For instance, in 1989 in France, 0.5 per cent of all fires damaged 40 per cent of the total area damaged, and 94 per cent of fires burnt less than 5 ha (Prometel, 1992).
The causes |
Traditionally, forest fires have been ascribed to natural causes such as lightning, along with accidents, vandalism and arson. Causes are more diverse than is often assumed, and fire initiation is neither as random, nor, in some cases, as meaningless as some analyses have suggested. Understanding the reasons why fires start is very helpful when determining what to do to prevent or reduce their incidence (Box 34B).
Natural fires do not represent a large proportion of the total number of fires in Europe. Analysis of UNECE-FAO statistics suggests that, in 1987, natural fires made up 8 per cent in Spain, 3 per cent in Finland, 2 per cent in former Czechoslovakia, and less than 0.1 per cent in West Germany and Italy (WWF, 1992).
Many accidents leading to forest fires stem from negligence coupled with lack of understanding about the risks of, for example, dropping cigarette ends, or people starting fires for camping and barbecues. Much of the traditional understanding of fire management has also been lost because of the depopulation of many rural areas. The risk of fire has been further increased by the greater mobility of urban dwellers, who visit forest areas more regularly, but who may not understand the risks of starting a fire. In some areas, such as the Mediterranean, increases in coastal populations are creating additional stresses on forests through the sheer numbers of people visiting them.
Analysis of UNECE-FAO fire statistics suggests that negligence of various kinds is an important cause of fire in most European countries, but generally less so than arson (although the causes of many fires remain undetected). For example, in 1987 accidental fire accounted for some 59 per cent of fires in Turkey, 50 per cent in Austria, 32 per cent in Portugal and 25 per cent in Spain (UNECE/FAO, 1990).
Arson remains the most important known cause of fire in much of Europe. For example, combined figures for the whole of the Mediterranean for 198185 indicate that negligence was the cause of 23 per cent of fires, arson accounted for 32 per cent, while the cause of 40 per cent of fires was unknown (WWF, 1992).
Finally, other activities such as military exercises and waste disposal may also result in fire accidents if not well under control. Unprotected power lines running over forestry can create sparks, thus directly causing fires.
Fire is traditionally used by farmers to clear the fields after harvesting and to provide nutrients to the soil through ashes. Fire is also used by shepherds to renew grassland. If these fires are not very well controlled (for instance, if they are initiated under weather conditions favourable to fire spreading quickly), they can spread to nearby forests and evolve into uncontrolled forest fires. Some other causes are mentioned by different authors (WWF, 1992): for example, fire for hunting, land speculation, wood speculation and private vengeance.
Consequences of fire on the environment |
In the Mediterranean part of Europe, much of the landscape is the result of the frequent occurrence of fires. Fires have an important impact on the environment: burnt wood loses its scenic and recreational values; particularly intense and long-lasting forest fires can cause serious soil damage by slow combustion of organic matter and humus in the soil; serious erosion risks may appear if violent storms occur soon after a fire, especially on slopes and fragile soils. If fires occur too frequently, there may not be sufficient time for the forest to recover, which leads to its conversion into shrubland. Fires have an impact on forest composition, favouring species resistant to fires such as the holm oak (Quercus ilex), cork oak (Quercus suber) and some pines. All these species resprout and regenerate quickly after fire (sometimes within a year).
Fires are likely to affect the whole fauna and flora of an ecosystem. Fires damage plants and threaten wildlife unable to escape. Some important animal species in the Mediterranean area have apparently suffered badly from forest fires, including wild boar (Sus scrofa), red deer (Cervus elaphus) and roe deer (Capreolus capreolus), badgers (Meles meles), porcupines (Hystrix cristata), and breeding birds (WWF, 1992). However, the effects on the dynamics of forest ecosystems are not always negative. For instance, a recent study has shown that the number of bird species is higher in burnt forests and remains higher for several years after a fire (Prodon, 1992). This is because the post-fire succession of growth offers a patchy vegetation (scattered bushes and young trees), which favours bird populations in general. This is also true for the diversity of forest undergrowth plant species.
Fires in radioactively contaminated forests pose a particularly serious problems (see Box 34C).
At the global level, forest burning contributes at least 20 per cent of the carbon dioxide released to the atmosphere each year from human activities. Many countries have emphasised the importance of the dry conditions in 1990 and 1991, both in terms of drought stress to trees and high frequency of forest fires. Any atmospheric changes that increase the frequency of dry conditions in Europe can have serious consequences for many forests, particularly in the south, by increasing the frequency of fires.
Economic costs |
Costs are difficult to calculate. Burnt wood has little commercial value but burnt timber can often still be sold, and indeed forest fires are sometimes started deliberately as a means of wood speculation.
UNECE-FAO analyses (1990 and 1992) attempt to look at losses of both timber and other uses. In the particularly bad forest-fire summer of 1985 in Europe, Bulgaria lost 22 400 m3, Italy 2 million m3, Portugal 7 million m3, Turkey 556 300 m3, and former Yugoslavia 950 000 m3 of timber. However, costs of timber are only part of the problem, and additional costs for fire fighting and lost recreational use, all add to the total financial losses. For example, in 1992, France spent about ECU83 million for fire fighting. In 1990, Italy lost an estimated ECU68 million in terms of wood and other tangible losses and ECU3 million in other losses (FAO, 1992). Social values (loss of aesthetic and recreational resources) are not possible to quantify in financial terms. Local people suffer if fires eliminate traditional grazing lands within forests. Forest fires in residential areas, which have become increasingly frequent in the Mediterranean area, have immediate effects on people's quality of life through destruction of property and possessions. Fires also kill a number of people every year, including fire fighters.
Strategies for prevention and fighting fires |
Any successful policy for the protection of forests against fires must have two objectives: to reduce the number of fire outbreaks; and to reduce the area burnt. The reduction of the number of fires has to be achieved by reducing the causes (in the Mediterranean region, 95 per cent of the fires are from human origin), while the reduction of the burnt-out area relies on prevention measures such as the installation of look-out structures, and on an active control and fire fighting once a fire has started. Since fire reduction is very much related to internal landuse conflicts, the discussion of fire protection measures below concentrates on those which help reduce the area burnt.
Prevention relates to the passive protection of the forest. Land management policies are an essential tool for minimising landuse conflicts and reducing fire risk. Forest management which takes fire into account should include regular thinning, brush clearance along roads, railways and power lines, and the plantation of stands/species which are less sensitive to fires. The most crucial infrastructure items to be developed for fire prevention are the creation of forest roads (which allow rapid intervention and act as fire-breaks), the provision of water supplies in the event of a fire and the establishment of fire-breaks.
In parallel with passive prevention, active protection measures include risk forecasting, involving analysis of meteorological data on a routine basis to foresee potential fire conditions, and regular watching, using fixed installations such as look-out towers or mobile ones (patrols and aircrafts), possibly with fire-fighting equipment. Since 1992, a daily exchange of information on the level of risk of forest fires during summer takes place between EU Member States and the European Commission; the objectives of this initiative were to provide the Southern countries with information on the hazard situation, and to realise a survey of the evolution of the risks.
When a fire has started, how quickly it can be stopped will strongly depend on the promptness of its detection and how it is fought by the different land-based and airborne systems, their number and the effectiveness of their coordination. Therefore, sound deployment of capabilities and training of qualified personnel are factors in the control of forest fires. Since 1991, the European Commission (DGXI) has developed several actions to improve mutual assistance between Member States of the EU: a self-tuition programme, a group of cooperation officers, a register of fighting means and pilot projects.
Prescribed burning can be used as a management tool to prepare land for replanting, to clear post-harvest debris, to destroy pests, etc, but also to prevent wild fires. Indeed, fire started under well-controlled conditions (in winter, with no wind) can be used to reduce the fuel load of the forest, that is, the litter undergrowth, over vast areas and at relatively low cost. This technique, which had fallen into disuse in much of Europe, has been reintroduced in some countries, where it proves to be very efficient (eg, in Portugal, France, Sweden). However, the conditions prevailing in Europe, that is, the high population density and the structure of land ownership half of the forest is private and the perception of the public are limiting factors for its extensive use.
Conclusions |
Fires represent a major disturbance of forests in Europe and a threat to nearby populations. The belief that the number and extent of fires are increasing is much debated. Indeed, it is only recently that fires have been recorded systematically. Forest fires represent only a part of the total number of fires (less than 50 per cent in Italy). Changes in landuses which are occurring in Southern Europe (abandonment of agricultural land, depopulation) are increasing fire risk. The seriousness of the problem is due to the fact that natural causes have been compounded by human action (negligence, accidents, burning as an agricultural or grazing practice, and arson). The control of the causes is complex since they are often indicators of conflicts and tensions in the overall system of land management. Action measures often need to go far beyond forest activities, because the causes of fire can be related to socio-economic, legal, structural, and even cultural factors. Therefore only an integrated and progressive approach based on a sound knowledge of local problems, sustained coordination between the different involved parties, and political determination to succeed can be successful.