History of Fire in Land-Use Systems of the Baltic Region
History of Fire in Land-Use Systems of the Baltic Region:
Implications on the Use of Prescribed Fire in Forestry, Nature Conservation and Landscape Management
Johann Georg Goldammer
Fire Ecology and Biomass Burning Research Group, Max Planck Institute for Chemistry, Biogeochemistry Department, c/o Freiburg University, 79110 Freiburg, GERMANY
Paper presented at the First Baltic Conference on Forest Fires
Radom-Katowice, Poland, 5-9 May 1998
1. Introduction: Fire in the History of Land-Use Systems in the Baltic Basin
2. Shifting Agriculture Methods: Examples from Germany
2.1 Coppice Forest Shifting Agriculture
2.2 High Forest Shifting Agriculture
2.3 Moor Burning
2.4 Use of Fire in Silvo-Pastoral Systems and in Silviculture
3. Slash-and-Burn Systems in Other European Countries
3.1 Sweden and Norway
3.2 Finland
3.3 Latvia, Lithuania, and Estonia
3.4 Russia
5.1 Historic Moor Cultivation
5.2 Burning Methods
5.3 The “Dry Fog”
6. Conclusions from European Fire History
6.1 The Post-World-War II Development
6.2 Current Changes of Paradigms in Nature Conservation
In the history of land-use in the countries bordering the Baltic Sea fire has been an important element in forestry, agriculture and pastoralism. The use of fire has contributed to shape landscapes of high ecological and cultural diversity, e.g. heathlands, open grasslands, meadows, and swidden (shifting) agriculture sites. In the Nordic countries historic natural fires caused by lightning and burning practises have also significantly influenced the composition and structure of forest ecosystems.
The rapid socio-economic changes in the post-World War II Baltic Region led also to a change of land-use systems and landscape patterns, resulting in elimination of traditional burning practises. New air quality standards and the generally prevailing opinion by the government administrations that fire would damage ecosystem stability and biodiversity, led to imposing of fire bans in most European countries.
It is now becoming evident that the abandonment of traditional land-use methods resulted in the elimination of disturbances which have characteristically shaped many valuable landscape types and ecosystems.
Changing paradigms in ecology and nature conservation currently lead to the reconsideration of fire-exclusion policies in certain sectors of nature conservation, forestry and landscape management.
In this paper some examples are presented of the application of fire in historic land-use systems in the countries bordering the Baltic Basin.In the future the use of prescribed fire in sustainable ecosystem management must be considered.
1. Introduction: Fire in the History of Land-Use Systems in the Baltic Basin
Charcoal particles embedded in soils and lake sediments provide evidence of fire in land-use systems significant importance since the neolithic (e.g. Clark et al. 1988). Most important was the use of fire in swidden agriculture and shifting cultivation systems. All over Europe methods and goals were common and similar to those still practised today in the tropics (Montag 1990).
Evidence of regular burning in open heather and moor landscapes which was common in Belgium, Denmark, France, Germany, southern Sweden and Norway, is also found in the literature and archived documents since the Middle Ages (Goldammer et al. 1997b, Pyne 1997). In Germany burning systems were first documented in the Odenwald in 1290 and in the Black Forest in 1344. In the 18th and 19th Century slash-and-burn systems were expanding due to rapid demographic changes (population growth) associated with increasing social problems (poverty, lack of land and food supply).
In Germany during the 18th and 19th century slash-and-burn agriculture was practised in all mountain regions, e.g.:
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South Germany and alpine countries: “Hackwaldwirtschaft, Reutberge und Reutfelder”
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Sieger Land: “Haubergswirtschaft”
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East of river Rhine: “Rottbüsche und Schiffelländereien”
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Westphalia, Pommern, Austria, northern France/Belgium: “Röderwaldwirtschaft und Röderlandbetriebe”
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Bavaria: “Birkenberge”
At the begin of the Industrial Revolution and the introduction of more efficient land-use technologies, including fertilizers and pesticides, slash-and-burn systems were more and more abandoned. However, in some countries slash-and-burn was still practised until the mid of the 20th Century. For instance, observations around 1900 in the Russian provinces (gouvernements) Olonetz, Nowgorod, Wologda, in northern Perm and Wjatha, and to a lesser extent in Pskow, St. Petersburg, and Ufa reveal that at that time ca. 43% of the cultivated land was on recently burned terrain (Heikinheimo 1916). In the German Black Forest in the vicinity of the city of Freiburg im Breisgau the swidden system of the “Reutebergwirtschaft” in 1950 was still practised on ca. 10.000 ha (Abetz 1955).
2. Shifting Agriculture Methods: Examples from Germany
Two main types of swidden agro-silvo-pastoral systems were distinguished in Germany and practised similarly in other European countries, the “Coppice Forest Shifting Agriculture” and the “High Forest Shifting Agriculture”.
2.1 Coppice Forest Shifting Agriculture
After clearcut of all stems the residues including litter and upper humus layer, and the herb-shrub fuels are burned to provide ash as fertilizer. Two main methods were applied:
Burning on heaps (“Schmoden” = “smouldering”)
All fuels were collected in small heaps which were covered by grass mats (swards) or soil (like a charcoal kiln). The smouldering combustion lasted ca. 2 to 3 days. The ash was distributed before seeding of agricultural crops.
Broadcast burning (“Überlandbrennen” = “over-land burning”)
The upper humus layer (sward) with herb-shrub layer was peeled. Under appropriate dry and windy weather conditions the dry fuels were ignited and burned with a surface fire. Coppices were protected by scraping the litter layer around the shoots.
Broadcast burning prescriptions were established by Chief Forester Eickemeyer (Hesse) in 1864. Among other he recommended:
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Establishment of firebreaks between area to be burned and neighbouring stand (3 m distance to hardwood stands, 6-8 m to conifer stands)
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Number of burning & safety personnel: 1 person per 1/2 ha to be burned
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Burning against the wind (backfire) and downslope
The Forest Law of Baden of 1836 banned the use of broadcast burning because of the danger of escaping wildfires and damages of coppice shoots which often occurred.
The Agricultural Phase
Different types of crops were seeded depending on the burn date:
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Early burns allowed summer seeding of wheat
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Rye was used for winter seeding
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Delay of seeding in the next spring would involve potatoes and oats. The agricultural phase was usually restricted to two years due to the regrowth of coppices
The Silvopastoral Phase
After ca. 8 to 10 years of forest growth the area was opened for cattle grazing.
The Forestry Phase
The total rotation period between clearcuts lasted between 15 and 20 years. Main species involved were oak, maple, birch, willow, beech, chestnut and pine.
In the 16th century a general tendency was observed that farmer prolonged the agro-pastoral phase at the expense of the forest production phase. Thus, the degradation of forests became visible, and the proportion of forest-depleted areas in many regions increased dramatically. Local decrees were issued which regulated the forest use.
Many forests recovered. But again in the 18th century the enormous population pressure lead to increasing slash-and-burn activities. This was the moment the forest services responded. In Rhineland-Palatia the Forest Service issued a decree that the agricultural period in the shifting cultivation cycle to be reduced to one year. Recovering forest areas furthermore had be fenced in order to protected from browsing wildlife and domestic cattle. Consequently, the depleted forest area recovered successively. In the early 19th century, however, two agricultural cycles were permitted again. The forest yield was generally better on non-burned coppice stands.
In many regions of the German landscapes the agro-silvopastoral shifting agriculture systems were conducted at local community level.
They were successively abandoned in the wake of the industrial revolution. The industrial needs of charcoal were replaced by coal, and even hardwood for railway sleepers were introduced from South America.
2.2 High Forest Shifting Agriculture
The shifting agriculture with high forest phase was usually called “Röderwaldbetrieb”, “Röder” or “roden” being the term for a non-forested area after clearcut. In the High Forest shifting agriculture mode the agricultural phase was much shorter than the forest rotation which – after planting of forest trees – usually ranged between 30 and 50 years.
The “Reutberge” of the Black Forest region (Southwest Germany) were usually clearcut and the non-utilized fuels burned downslope, a technique which was used in many European mountain regions. If the forest regeneration was not conducted properly, the slash-and-burn sites often degraded. Cattle trampling and erosion were the main drivers of site degradation. Around 1850 70,000 ha of “Reutberge” were actively managed, and in 1950 the area was still 10,000 ha. After World War II the rehabilitation of former degraded slash-and-burn fields was promoted by intensive reforestation campaigns.
Fig.1. Oil painting of traditional swidden agriculture (“Reutebrennen”) in the Black forest region, Germany, as practised until the mid of the 20th Century, Source: Archive, Fire Ecology Resaerch Group/Global Fire Monitoring Center.
The swidden moor cultivation was very common in Northern Europe since the Middle Ages. Moorlands provided space for the steadily growing rural population. The fire cultivation involved draining, turf cutting and burning. Fire was needed to break down the rootmats of the moor layer which otherwise could not be used for sowing or planting. Another method was the burning with a fast-running surface fire which would not penetrated deeply into the organic layers (see para. 5).
2.4 Use of Fire in Silvo-Pastoral Systems and in Silviculture
The introduction of fire in standing forest for improving silvo-pastoral systems was common in some regions of Germany. Surface fires usually killed the thin-barked beeches, while old, thick-barked oaks survived. Under the wide-spaced oak stand this kind of burning practice produced open forest structures, dominated by oaks, and providing abundant grass-herb cover which provided grazing resources. Light-demanding oaks regenerated much easier than the shade-tolerant beeches, thus, both effects, the selective force of fire and the secondary consequences of open stands favoured the formation of large pure oak stands at the expense of the climax formation potentially dominate by beech.
Thus, the extremely valuable oak forests, e.g. in the Spessart region, are not “natural”: they are the result of the manifold impacts of humans in the cultural landscape (for details: see Goldammer et al. 1997a, b; Page et al. 1997).
While all the above-mentioned burning practices were driven by the agro-pastoral land users, foresters also began to develop their own views of the use of fire in forestry and silviculture.
In 1925 the German forester A. Conrad describes his experiences and hypotheses on the use of prescribed fire in a forestry journal, entitled “The Surface Fire as a Friend of the Forester” (Conrad 1925). He summarizes his thoughts on the use of prescribed burning for stimulation of natural regeneration of pine and spruce, to control dangerous forest insects during their different development stages in the forest litter and upper humus layers, and he even includes thoughts on the use of fire for fuel reduction as a preventive measure against high-intensity fires.
Many other German foresters had similar ideas (e.g., Müller 1929). However, they were never put into practice because of the prevailing dogmatic attitude towards fire which was considered as harmful and destructive to forests.
Today we recognize that the basic principles and prescriptions of prescribed burning, both within standing forests and outside of forests, have been formulated in Europe. The fire knowledge of farmers and foresters from Central and Northern Europe transmigrated to the New World where it was further developed and refined while Europe was in fire dormancy. Proposals and early test results on the use of prescribed burning in silviculture and fire management in Central Europe (e.g., Goldammer 1977, 1978, 1979) remained unnoticed until today.
3. Slash-and-Burn Systems in Other European Countries
The botanist Linné in 1800 first described the slash-and-burn systems in Sweden, usually called “svedjebruk”. Forest trees were usually pruned (to man-height) in the first year, felled and burned after drying in the second year. Incompletely combusted tree stems were removed and later burned on piles. The site was then planted with rye, barley and turnip. Several years later invading birch trees took over the sites. This system was also found in Norway. Burning on sites with a thick raw humus layer usually improved site conditions so that the next forest generation was more vigorous and productive. For detailed information on the history of burning in Norway see Bleken et al. 1997. Comprehensive information on Sweden’s fire history is given by e.g. Bradshaw and Zackrisson (1990), Granström (1991, 1993), Page et al. (1997), Pyne (1997), and Niklasson (1998).
Fig.2+3. Revival of traditional “svedjebruk” practice in Northern Sweden. Photos: Hans Page, Fire Ecology Research Group/Global Fire Monitoring Center
In the first phase of the swidden agriculture era in Finland the more fertile forests dominated by broadleaved trees were burned in the vicinity of villages. In the 16th century, shifting cultivation began to be practised in central Finland – with a technique to cut down and burn mature stands of spruce. The new technique led to the wider adoption of shifting cultivation and also the spreading out of human settlement throughout the country.
A widespread method was ring-barking (girdling) of standing trees (perhaps as many as 300 per hectare). This was a preparatory stage in shifting cultivation in pine-dominated woodland areas. Ring-barking killed the standing trees. The drying-up of the trees and their roots made the raw-humus layer more porous. This in turn improved the outcome of the burning. Not all of the ring-barked trees were necessarily cut down.
The fallow period in turnip, barley and rye shifting cultivation was 20-40 years. A fresh opening would be made in a Grey Alder woods or a mixed woods that had been established by natural regeneration in the area. Fast-growing tree species did not take long to build up a sufficient amount of combustible woody material. Plots would be cropped for 1-2 years and then they would be left fallow and allowed to revert to forest.
Like in the central European forms of shifting agriculture, during the intervals between consecutive swidden operations, the plots of land would often serve as forest pastures for cattle husbandry. Grazing of farm animals hindered the forestation, as mere grass was not adequate to satisfy the nutritional requirements of the farm stock. The cows and horses would eat tree seedlings and lower branches and consequently swidden areas would develop into patchy forests. These areas would also be accessed for winter fodder for the cattle and horses and conifer branches as bedding. Collecting of conifer branches tended to reduce the survival of spruce. Fields and meadows had to be fenced, which consumed a lot of sapling and thus influenced the species composition of swidden areas.
Heikinheimo’s studies (1915) revealed that shifting cultivation in Finland was practised over more than 4 million hectares per year. By the beginning of this century, some 50 to 75 percent of Finland’s forest area had been exploited in this manner. In the eastern part of Finland, shifting cultivation was practised longer and more intensively than anywhere else in the country.
Shifting cultivation gave rise to conflicting opinions. It was a necessity for the livelihood of the rural population. Nevertheless, the government authorities were worried because of it. On the other hand, already in the 19th century it was feared that loss of forest cover because of shifting cultivation would lead to a cooling of the climate and to Finland becoming unsuitable for human settlement. Another, more urgent cause for concern involved the rising economic significance of forests. Sawtimber and timber for mining were becoming increasingly important. Concern over the loss of the country’s forest resources culminated in inviting of the German forestry expert von Berg in 1858 to come and report on the state of Finland’s forests.
The report gave a very gloomy view of the forests in areas of intensive shifting cultivation. Moreover, tar distillation, a practice that destroyed the best trees, had created large areas of dismal landscape, especially in western Finland. The forests in the vicinity of villages were all-aged woods of pine, hardwoods and mixed species. Shifting cultivation had already made it difficult to find firewood or timber for building and construction near villages.
Legislation was passed in an endeavour to safeguard timber for industrial needs. A bill passed in 1734 made it compulsory for farmers to have a licence before they could burn over forests. But it was not until the end of the century that this regulation began to have a real effect in the heartland of shifting cultivation. The Private Forest Act of 1929 still permitted the practice of shifting cultivation, but only in places where it could be defended as being a sensible practice.
In addition to influencing the availability of timber, shifting cultivation had a major influence on the landscape, the cycling of soil nutrients and regional biodiversity. It also influenced the nutritional status of inland waters and the species composition of the forests. The results of the first national forest inventory, conducted in 1921-1923, showed that 50-60 % the forest land in south-eastern Finland was covered by woodlands less than 40 years of age. Broadleaved species accounted for nearly half of the forest area with the share of spruce being only 12-15 %. The most recent inventory conducted in the same part of the country, and completed in 1988, revealed that spruce and pine amount to 40 % each with broadleaves making up the remaining 20 %. This shows that, following the demise of shifting cultivation, Finland’s forests have experienced a significant increase in the proportion of spruce.
Prescribed Burning in Finland
With the end of the era of shifting cultivation in the early part of this century, methods derived from this practice began to find use in the regeneration of under-productive forests. Burning of logging waste and the raw humus layer was recommended as a means of promoting the natural restocking of regeneration sites. Broadcast-seeding-on-snow in spring, with prescribed burning preceding it, found widespread use in the 1920s. Prescribed burning in those times amounted to approx. 8,000 ha per year. With time, however, this method’s popularity declined; in the 1930’s, the annual area burnt in this manner was only a few hundred hectares a year.
Fig.4. Silvicultural burning in Finland as seen by an artist in the late 19th Century. Source: Archive, Fire Ecology Resaerch Group/Global Fire Monitoring Center.
Prescribed burning enjoyed a comeback after World War II and the peak of over 30,000 ha was reached in the mid-1950’s. It was particularly useful in assisting with the regeneration of northern Finland’s spruce stands to pine, characterised by their thick layer of raw humus. However, this prescribed burning’s second coming came to an end in the latter half of the 1960s when it was replaced by mechanized site preparation. The area annually treated fell to 500-1000 ha a year and stayed at that level up to the recent past.
The reasons behind the decline in prescribed burning have primarily been technical. The success of prescribed burning depends on weather conditions and this leads to difficulties in organising the operation. The risk of fire getting out of control, the increasing popularity of mechanised site preparation, the risk of nutrients being leached from the soil, and the increased risk for fungal or insect epidemics in the dense young pine stands are the most common forest regeneration problems associated with prescribed burning.
Prescribed burning has many advantageous influences on the physical, chemical and biological properties of the soil. It also affects forest succession and biological diversity (Annila 1993). These advantageous effects depend on site fertility and the intensity of the fire.
Prescribed burning is recommended for application on moist and dryish mineral soils with sufficient stores of soil water. On more fertile sites, prescribed burning can reduce the availability of phosphorus. The nitrogen released from burning organic matter is lost entirely into the atmosphere and consequently the stores of nitrogen in the forest are reduced. This loss of nitrogen is not, however, fatal for the development of new forest growth, because only a small proportion of the nitrogen stored in forest soils is in a mineralised form. Prescribed burning has an advantageous influence of the pH of the humus layer, which may rise by 1-2 units and stay there for several decades. The rise in pH in the uppermost mineral soil layer has been modest.
Artificially regenerated forests by planting or seeding in Finland currently amount to slightly more than 4 million ha. Since the total productive forest area is approx. 20 million ha, artificially regenerated forests represent 20 % of the whole. Following soil scarification, regeneration sites produce an abundance of naturally arisen conifer and hardwood seedlings, and these develop into mixed woods (Parviainen 1988). Over a period of 80-90 years, prescribed burning has been applied on a total of 0.5 million ha. This corresponds to 12% of Finland’s artificially regenerated forests and 2-3% of the total forest area.
3.3. Latvia, Lithuania, and Estonia
Slash-and-burn agriculture was less common in Latvia and Lithuania because 85% of the forests were government-owned, and forestry was supported. However, the use of fire is well documented. In Lithuania forests were cut and the woody material was transported to the field and burned. In Latvia woody material was burned in rows; report from 1795 reveal that heap burning was preferred on poor soils. In Estonia the wood of alder was preferred material for burning on the fields and distribution of ash for fertilizing.
Observations around 1900 in the Russian provinces (gouvernements) Olonetz, Nowgorod, Wologda, in northern Perm and Wjatha, and to a lesser extent in Pskow, St. Petersburg, and Ufa reveal that at that time ca. 43% of the cultivated land was on recently burned terrain (Heikinheimo 1915).
Shifting cultivation methods were very similar to the techniques used in the Fennoscandian region; the consequences of the swidden system on forest species composition was also very similar. Swidden agriculture in Russia is documented since the year 946.
The extended Calluna heather regions stretches within the temperate-wet climate belt of Northwest Europe between Great Britain, Ireland, Southern Norway and Sweden, Denmark, Northwest Germany, the Netherlands, Northern Belgium and France. Natural climax vegetation under the climate and site conditions would be mixed oak-beech, beech, or mixed oak-birch forests.
The main human influence on these sites was the intensive utilization of wood, mowing, sheep grazing, litter and sward cutting, peaking between 1800 and 1850. Heather burning was common in all the regions mentioned, particularly in Great Britain.
The main reason for burning was the need to replace overmature heather which becomes moribund after 14 to 16 years by freshly regenerated plants. The release of nutrients stimulates heather growth, as well as the fire temperatures which assist in seed cracking. Broadcast burning was often done first, followed by the removal of the grass-root sward which was then burned separately.
Heather burning was often a cause of wildfires which escaped into forests. Consequently, first forest protection regulations were issued which required to obtain a burning permit from the forest authorities, such as in 1651. After the decline of sheep production in the 19th and 20th centuries the heathlands are considered as important floristic refugia and landscape elements which need to be protected from succession towards climax forest.
In the 18th century the landscape of Northern Germany was dominated by large uncultivated bogs and swamps. In 1770 about 1/7 of the total area of Niedersachsen was uncultivated bogs. The common people were afraid of these ‘dark and wild’ places and tried to stay away from these areas, which were perceived to be haunted. But with the population growth of the end of the 18th century, people were forced to enlarge the area under production and started to cultivate these areas. To fulfil their plans they began to burn the bogs.
Fig.5. Moor burning in Friesland around the turn of the century. Smoke from these land-use fires sometimes covered large areas of Europe. Source: Archive, Fire Ecology Research Group/Global Fire Monitoring Center.
The chosen plots for the new settlement must first be drained and levelled of. This work was done in autumn with the establishment of ditches which were laid out in such a way that the plot was divided into long narrow strips. The purpose of this work was to dry out the plot for further treatment. In spring of the following year, the upper organic layer of the bog was removed with big hoes, and the duff was cut out in quadratic clods. If the year was very wet this work was done in early autumn. In these wet years the ground had to be broken up several times.
In May work requiring strong men began: the clods had to be thrown and stacked into little piles. Thereafter these piles of stacked and dried clods were ignited. As soon as the material was half-burned, the still burning pieces were distributed against the wind all over the field. The fire had to burn for several days at calm weather for several days. It was very important that the fire be watched over so that it did not penetrate the deeper organic layers. The bog area only had to burn slightly or, in other words, smoulder. This work was extremely strenuous and the workers’ clothes were covered with ash and dust, while their eyes were constantly a shade of red during the burns.
The burning of the bog began mainly in mid-May and ended in June. The drying of the organic material and the heat caused the normally barely accessible plant nutrients of the bog to break up enabling the cultivation of oat and buckwheat on the freshly burned fields, without fertilization.
The burning of the bogs was however not possible on the same plot year after year, over a longer period of time. In general a single plot was burned and tilled over a period of six to seven years. After the cultivation period a fallow period of 20 years was necessary. For this reason shifting cultivation was practised, where thereafter a neighbouring plot was used for the next 6 to 7 years, after which new land was then cultivated.
The burning of bogs was first noted in the year 1583. At that time the regional administrator (Drost) of the Emsland enacted a strict ordinance against this kind of “cultivation”.
In 1669 similar ordinances existed in the counties of Oldenburg and Delmenhorst. In 1720 the following was written: “In the Emsland the farmers are not willing to desist burning the bogs. They rather would pay the fine and continue to burn.”
The first stimulus for the agricultural use of the moor came from the Netherlands. The upper organic layer of the moor was used for peat production and afterwards the dismantled moor was cultivated (“Fehn” cultivation).
Burning practices were introduced as well from the Netherlands to Eastern Friesland and spread from there throughout northwest German bog areas.
The burning of the bogs had an oppressive effect on the northwest German areas, even in areas far away. This effect, the “smell of burning” was known under the term “High Smoke”. What is “High Smoke”? Why was the smoke of the bogs called “High Smoke”?
The bog researcher Racke wrote: “The dark, thick and heavy, evil-smelling smoke covered the land for miles. In the spring often in the shape of a high dark wall, it rapidly gathers like a storm-cloud and covers the sun so that it looks like a dim disc. At more favourable conditions the smoke escapes, and the longer it travels the weaker it gets, ending as haze, carried into areas far away as Hungary or Southern France. In Germany this phenomenon is called “Heerauch”, “Haarrauch”, “Höhenrauch” and is hardly liked. Public opinion made it responsible for all sorts of damage. It is said that it drives away rain. The farmers of the “Alte Land” said that it damages the blossoms of fruit trees, and that it should even drive melancholical people to suicide.” For years the inhabitants of countries far away from the actual bog burns were puzzled over the origin of the recurring smoke. The French, for example, thought that the “brouillard sec” was dried fog. The English called the bogsmoke “dry fog”. The puzzlement did not stop:
In 1657 the bog burnings began on 6 May in Northern Friesland carried by strong easterly winds. Already on the next day the smoke had reached Utrecht, and a little bit later had changed direction, passing Leeuwarden towards Den Helder reaching the sea on 15 May. There, the wind changed suddenly northwest and drove the bog smoke back, so that on 16 May it had reached Utrecht and Nijmwegen again. At the same time the smoke was also noticed in Hannover, Münster, Köln, Bonn, and Frankfurt. On 17 May the smoke reached Vienna, on the 18th May Dresden and Krakau on 19 May.
6. Conclusions from European Fire History
We recognize that fire has been used since hundreds and thousands of years in the European landscape. The physiognomy of fire was very similar to what we see in the tropics today. Even the smoke problems arising from large-scale fire use were similar at a time when European societies were growing and when forests and wildlands were transformed to agricultural lands. The two tropical countries Indonesia and Brazil, to name the most prominent smoke sources of 1997-98, are nations in transition from forest countries to modern agrarian and industrial societies. The difference between the tropics and temperate and boreal Europe, however, is the fact that the tropical soils in most cases are not able to carry sustainable agriculture and plantation systems, and indiscriminate burning has ore detrimental impacts of biodiversity and vegetation stability than it has in Europe. In this regard, the tropics are in a general disadvantaged situation.
Back to Europe: We recognize that patterns in vegetation structure and the very typical landscape elements in Europe have been shaped by intensive land use in which fire had played a significant role.
6.1 The Post-World-War II Development
Basically the development after the Second World War brought the end of slash-and-burn agriculture and the use of open burning. In addition, the exodus of rural population led to increasing use of machinery, pesticides and fertilizers.
For many years the official nature conservation administration believed that nature conservation in our latitudes would be equal to complete protection, i.e. absence of all human interferences. Thus, burning banned by nature conservation laws, by regulations on waste disposal or by air quality regulations.
Already in the 1970s biologists and ecologists began to think about the restoration of traditional land-use methods or “disturbance processes” in order to maintain the old cultural landscapes. The concept behind this idea was that in the old agricultural and pastoral systems which were less or not intensively managed, the plant biomass production was higher than the natural decomposition. Thus, fire seemed to be an appropriate solution to keep these systems dynamic and open.
The Calluna heathlands were a very visible example. Overmaturing and moribund heather began to change the large parts of this typical open and species-rich landscape which began to reconvert into forest.
First investigations in the 1970s looked at different treatments for theses endangered ecosystems (Tab.1).
Tab.1. Impacts of different treatment methods of heather regeneration (Muhle 1974)
Treatment Heather Regeneration Control of Bush and Tree Encroachment Nutrient Status Sward
(raw humus)
Cutting Positive but slow Efficient High nutrient depletion Mowing Positive but slow Not efficient Moderate nutrient depletion Mulching Positive Mostly efficient Increase of litter layer Rotary Tilling Unknown Unknown Mobilization of Nutrients Burning Positive Efficient Depletion of C, N and S
6.2 Current Changes of Paradigms in Nature Conservation
Since a couple of years a new trend in nature conservation, landscape management and forestry in Europe is observed. A new generation of young scientists and officials in the public administrations, the forest services, and the universities, and an increasing number of activists in non-government organizations are taking over responsibilities. They all went through the modern school of ecology, and they are more aware of the importance of natural and human-induced disturbance processes in the management of our lands. At present new initiatives are coming up to restore fire as a dynamic and vital element to maintain the cultural and ecological heritage as expressed in the formation of landscapes and biodiversity patterns.
It was only about two years ago that ecologists and nature conservationists in Germany began to think about restoring the use of fire in those landscapes that had been treated with fire historically and which were threatened by the exclusion of all disturbance. In Germany a “fire revolution” swept over the offices of the public administrations and the media. While local farmers are still punished for the illegal use of fire, the ecologists and fire scientists began to sort out the pros and cons of restoring fire in maintaining biodiversity and landscape aesthetics. Within less than a year four scientific workshops were held at the State Academies for Nature Conservation in Lower Saxony, Hesse, and Baden-Württemberg, and finally, in August 1997, the Federal German Nature Conservation Academy held a workshop on “Restoration of Dynamic Processes in Nature Conservation”, in which fire played a key issue. In 1997 the first large prescribed burning research program began in the State of Baden-Württemberg, aiming to investigate the use of prescribed burning in the management of hedge and slope terrain in the viticulture region of Southwest Germany. The use of fire to maintain or restore grass cover, a habitat for endangered flora and fauna, is the objective of a program which is driven by the dramatically increasing costs for subsidized landscape gardening and the fact that many of the vulnerable sites have been lost to the succession towards bush and tree cover. For more details on prescribed burning see the proceedings of the Workshop “Fire in Nature Conservation” of the Alfred Toepfer Akademie für Naturschutz (1997).
The changing paradigm in nature conservation in Germany is clearly visible. The signals emitted by nature conservation fires clearly show that the fire ban imposed on German landscapes in the mid-1970s cannot be kept any longer. The solutions, however, must consider the manifold sensitivities of an industrial society, in which a high awareness on environmental issues determines day-to-day politics.
Fig.6. Prescribed fire experiment in the Kaiserstuhl viticulture area, Southwest Germany: First experiments in January 1998. Photo: Fire Ecology Research Group/Global Fire Monitoring Center.
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