What are forests?
Forest diversity in Europe
Plant formations in Europe have a parallel but quite different layout. Their structure is influenced by the oceanic climate in the western part of the continent and the continental climate in the east. There are conditions favorable for European forest vegetation south of the arid tundra of the Arctic. European forest vegetation begins with a stretch of shrubs and rare birch forests on the Scandinavian Peninsula and in Russia. Further south we will find the taiga, consisting of conifers, such as spruce and pine, and to some extent fir and birch. Moving closer towards the equator, we are likely to spot more and more deciduous species: aspen, fewer elm, alder, maple and lime. Further to the south the taiga zone passes into deciduous and mixed forests of oak, beech and other species. In Western Europe, which does not stretch that far to the north, we will not find a taiga zone. We will find unique forest vegetation along the Atlantic coast (the coasts of west Norway, Great Britain, Ireland, western Spain and Portugal), such as moors with beeches and oaks. Further, in areas with a milder climate, we will find the typical forests of the region. On the shores of the Mediterranean and in the southern and central parts of the Iberian Peninsula we can find typical Mediterranean vegetation, dominated by sclerophyllous, eternal green thicket, formed after the destruction of forests. The meridional position of an area, as well as its height, influences the composition of the forest. In southern Europe we can find forests at a higher altitude (in Bulgaria at 2300 meters above sea level) than in northern Europe (in Scotland at 500 meters above sea level).
The original European vegetation has changed as a result of the economic activity, especially in the central and southern part of the continent. That occurred at a smaller scale in the north and north eastern part. In the British Isles natural vegetation covers only 10 % of the land (not only forests, but also heath land and bog), whilst in northern Scandinavia and Russia this percentage comes up to 90%. However, these are areas unsuitable for agriculture because of their climate.
The diversity of species in the forests depends on the geographical position, but also on the forest management policy implemented over the years. For the past 200 years, European forestry has preferred monospecific coniferous tree strands (mainly spruce and pine), resulting in the reduction of mixed and deciduous forests. Currently, due to the reconstruction of tree stands, there are more forest areas adapted to their natural habitat.
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Across Europe, mixed forests cover about 14 % of forest area. The largest shares of these tree strands are found in Malta (60 %), Czech Republic (56 %), Latvia and Estonia (above 40 %). Monospecific coniferous forests dominate because of natural conditions (climate and soil), mainly in northern countries (Scandinavia) and in mountain areas (Austria, Germany, Switzerland).
Coniferous species sometimes dominate because of economic decisions related to forest management. In Great Britain and Ireland, the large share of coniferous species is the result of a long-term forest policy, which supported the cultivation of sitka spruce - an alien species to the flora of Europe. Deciduous species play a greater role in countries situated in the south of the continent: Serbia, Bosnia and Herzegovina, Croatia (80 %), Hungary and Italy (70 %).
One way to measure resources in a forest is to calculate the growing stock which is the volume of the total standing timber at a particular time. Only wood suitable for processing is usually calculated, excluding thinner branches. The growing stock in the forests of Europe varies. In a single species stand, it depends on the age, the composition, the structure and the density of the forest. The average growing stock in the whole continent is about 140m3/ha, while growing stock in Ireland, Greece and Spain are below 100 m3/ha. In the alpine countries these numbers are much greater due to high rainfall and large tree strands of fir and spruce. In Austria it amounts to 309 m3/ha, in Slovenia and Germany - around 280 m3/ha. Forests in Slovakia and the Czech Republic have an average of 260 m3/ha because of the domination of hill and mountain forests.
In order to have sustainable forest management we need to know the annual increase of wood volume (annual increment). The volume of the timber logged every year, is not permitted to exceed the annual increment. More specifically, is permitted to be logged only a 60-70% of the annual increment every year. Tree stands with the highest growth rate are situated in western and central Europe (5 m3/ha per year). Limited growth is due to the following factors: short growing season in Europe and drought in southern Europe. Factors speeding up growth are: longer growing season in the south and higher amount of rainfall associated with milder maritime climate in the west.
Among European forests one can find areas which provide firewood. Tree stands providing firewood consist of tall and thin trees and species sprouting from a cut tree. These stands rarely exceed 30 years old and they are treated as forests of lower category. They are located mainly in southern Europe - in France, Italy and Greece. Forests with high trees coming from seeds and seedlings are the most valuable category. The age of these forests is distinguished by different age classes (20 years). The largest areas are occupied by trees between 20-80 years old (II-IV class). That resulted from afforestation after World War II, which took place in the central part of the continent, due to changes of borders and land ownership. In Europe there are 13 million hectares of forests, more than 100 years, which will continue to exist because of the restrictions enforced for environmental protection and because of social pressure. Age classes of forests are evenly distributed in Switzerland, Luxembourg, Czech Republic, Finland and Norway. Ireland is among the countries with an irregular age structure of tree strands. That resulted from afforestation funded by the European Union. Countries in a similar situation are Portugal, Austria and Denmark. On the other hand in Germany, the percentage of the tree stands of a younger age group is extremely low as a result of forest cultivation and forest regeneration. For example, the age for pine felling in the Nordic countries ranges from 110 to 180 years, in Central Europe from 80 to 120 years, in Hungary from 60-70 years and in the countries bordering the Atlantic Ocean up to 50 years (which is also an index of the species growth rate).
The geographical location of a country affects the richness of fauna and flora in forests. There is certainly a greater diversity in species in the south of the continent.
Coniferous species sometimes dominate because of economic decisions related to forest management. In Great Britain and Ireland, the large share of coniferous species is the result of a long-term forest policy, which supported the cultivation of sitka spruce - an alien species to the flora of Europe. Deciduous species play a greater role in countries situated in the south of the continent: Serbia, Bosnia and Herzegovina, Croatia (80 %), Hungary and Italy (70 %).
One way to measure resources in a forest is to calculate the growing stock which is the volume of the total standing timber at a particular time. Only wood suitable for processing is usually calculated, excluding thinner branches. The growing stock in the forests of Europe varies. In a single species stand, it depends on the age, the composition, the structure and the density of the forest. The average growing stock in the whole continent is about 140m3/ha, while growing stock in Ireland, Greece and Spain are below 100 m3/ha. In the alpine countries these numbers are much greater due to high rainfall and large tree strands of fir and spruce. In Austria it amounts to 309 m3/ha, in Slovenia and Germany - around 280 m3/ha. Forests in Slovakia and the Czech Republic have an average of 260 m3/ha because of the domination of hill and mountain forests.
In order to have sustainable forest management we need to know the annual increase of wood volume (annual increment). The volume of the timber logged every year, is not permitted to exceed the annual increment. More specifically, is permitted to be logged only a 60-70% of the annual increment every year. Tree stands with the highest growth rate are situated in western and central Europe (5 m3/ha per year). Limited growth is due to the following factors: short growing season in Europe and drought in southern Europe. Factors speeding up growth are: longer growing season in the south and higher amount of rainfall associated with milder maritime climate in the west.
Among European forests one can find areas which provide firewood. Tree stands providing firewood consist of tall and thin trees and species sprouting from a cut tree. These stands rarely exceed 30 years old and they are treated as forests of lower category. They are located mainly in southern Europe - in France, Italy and Greece. Forests with high trees coming from seeds and seedlings are the most valuable category. The age of these forests is distinguished by different age classes (20 years). The largest areas are occupied by trees between 20-80 years old (II-IV class). That resulted from afforestation after World War II, which took place in the central part of the continent, due to changes of borders and land ownership. In Europe there are 13 million hectares of forests, more than 100 years, which will continue to exist because of the restrictions enforced for environmental protection and because of social pressure. Age classes of forests are evenly distributed in Switzerland, Luxembourg, Czech Republic, Finland and Norway. Ireland is among the countries with an irregular age structure of tree strands. That resulted from afforestation funded by the European Union. Countries in a similar situation are Portugal, Austria and Denmark. On the other hand in Germany, the percentage of the tree stands of a younger age group is extremely low as a result of forest cultivation and forest regeneration. For example, the age for pine felling in the Nordic countries ranges from 110 to 180 years, in Central Europe from 80 to 120 years, in Hungary from 60-70 years and in the countries bordering the Atlantic Ocean up to 50 years (which is also an index of the species growth rate).
The geographical location of a country affects the richness of fauna and flora in forests. There is certainly a greater diversity in species in the south of the continent.
European forests consist of around 150 species of trees, all at different distribution. The largest area is covered by pine, spruce, beech, fir and oak.
Depending on the location of the country, between 200 and 6,000 vascular plants can be found. The majority of them are found in countries in the south and east of Europe and less in the north of Europe. |
The problem for some of the forests is the large number of alien species. In Northwest countries, introduced species take up an average of 15 % of forest areas, but in some countries this percentage is much higher (Ireland, Denmark, Iceland, Great Britain, Hungary, the Benelux countries). In the group of alien species, we can also include species that grow well away from their natural habitat. Among coniferous species one should first mention spruce, Sitka spruce, Douglas fir, and several species of pine. Among deciduous trees, non-native species include red oak, robinia and different poplar species. When moisture and temperature conditions are favourable, eucalyptus tree covers large forest areas (Spain, Portugal). Some of the alien species which are invasive, have adapted to the European forest ecosystems and are now occupying new areas. Some of them are: robinia – black locust (Robinia pseudoacacia) and black cherry (Prunus serotina), and Ailanthus altissima (Slovenia, Albania) in the south-east.
Forests are home to half of the mammals of Europe. Their number depends on the location and history of the countries’ economy. The largest group of mammals lives in the forests of south-eastern Europe, the Czech Republic, Slovakia and Lithuania. Moreover, in the Czech Republic, Slovakia, Austria, Poland, Scandinavia and Lithuania we can spot a large number of nesting bird species in forests. Significantly fewer nesting birds are found in the forests of Germany, Italy and the Benelux countries.
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