Pine forest
Like the species-rich genus Pinus itself, pine forests appear in a wide variety of forms around the world. Three species of pine occur naturally in Central Europe. The most common and widespread species is the Scots pine ( Pinus sylvestris ). It is the most common species of pine everywhere and the only naturally occurring species of pine in the northern part. Only in Austria is the southern European montane widespread black pine ( Pinus nigra subsp. Nigra ) seldom found; in Germany it was occasionally cultivated for forestry and is overgrown, but does not form natural forests. The form-rich mountain pine ( Pinus mugo ) forms in its prostrate form (subsp. Mugo ) bushes in the mountains at the tree line, its upright growth forms (subsp. Uncinata and rotundata ) can occasionally appear to form forests . The fourth species could be the Swiss stone pine or Swiss stone pine ( Pinus cembra ), which forms forests on the alpine tree line. Because of their completely different ecology, these are not dealt with here (see also: Swiss stone pine-larch forest ).
The Scots pine as a forest tree
Although the Scots pine, like almost all tree species, has its optimum development on well-water and base-supplied soils with medium site conditions, it cannot hold its own against the competition of other tree species on these. Due to the competition, it is pushed to extreme locations, where it benefits from its particular frugality towards extreme location conditions, so that the superior species cannot follow it here. In Central Europe, natural pine forests are therefore always forests in extreme locations. They come to dominate in three ecologically sharply separated location areas.
- Lime dry pine forests grow on extremely dry, shallow soils over limestone. Tree species are Scots pine and black pine.
- Sand and silicate pine forests grow on nutrient-poor, dry, extremely acidic soils at the absolute nutrient deficiency limit of the forest. The tree species is the Scots pine.
- Pine bog forests also grow on extremely acidic but water-saturated soils, mostly on the edge of open raised bogs. Tree species are Scots pine and mountain pine.
Except for the tree species Scots pine, these forest types do not have a single plant species in common. Accordingly, they are classified differently in the plant sociological system. For the structure of the pine forests, see below.
The Scots pine needs a lot of light to germinate and grow, and in turn it lets a lot of light through its crown. Pine forests, especially natural ones on poor locations, therefore usually have a continuous layer of herbs or moss, in which species with a main distribution outside the forests can also grow. Due to its light, wind-dispersed seeds and its frugality on raw soil locations, the Scots pine is a typical pioneer tree species, which often appears as the first tree species in the reforestation of previously forest-free locations, but can often be displaced by other tree species in the course of the succession if they the site through humus formation has improved so much that it can thrive. Since the availability of nutrients in very poor soils depends more on the humus supply than on the parent rock, pine forests can now also develop “natural” forest communities in places where the natural soil cover has been destroyed or eroded. Soils that are impoverished by litter use and forest pasture are therefore now often covered by pine forests as potential natural vegetation , although they emerged from deciduous forests.
Distribution of the pine forests in Germany
Due to the transitional character of the pine forests and the wide distribution of planted pine forests outside of their area of origin, the natural distribution area of the Scots pine in Germany, and thus the distribution of the natural pine forests, is an old controversial topic in forest ecology. It is clear that Scots pine initially formed extensive forests all over Germany in the post-glacial period (in the Preboreal region, approx. 10,000 years before today), which were later more or less displaced. Due to the very light, far-flung pollen, the question of the extent of natural pine forests (especially those that are only sparsely sprinkled) cannot be decided by pollen research. Today it is assumed that extensive natural pine forests occurred mainly in the northeast German lowlands. Hesmer and Schroeder proved that it was naturally absent in northwest Germany, with the exception of tiny relict occurrences on the edges of the moor. The extensive pine forests of Lower Saxony and Westphalia grow mainly instead of the former beech and oak forests. In southern Germany, pine forests occur more or less like islands, for example in the Upper Palatinate, in the Upper Rhine Valley, in the Alpine foothills and scattered in some low mountain ranges.
Pine forest types
Lime dry pine forests
Pine forests on shallow limestone soils are rich in species and are home to particularly rare and striking plant species, which is why they were explored extensively early on. The only in southern Germany, v. a. Forests widespread in the foothills of the Alps were often called “relict pine forests” because it was imagined that they were remnants of what was once a widespread form of vegetation from the post-ice age. They are characteristic of the montane elevation of the Alps and the eastern low mountain range, where, in addition to limestone rocks, they can also form extensive stands on the limestone gravel of some Alpine rivers such as the Lech and Isar. Their isolated position is made clear by the fact that they form a separate class Erico-Pinetea with the only order Erico-Pinetalia in the plant-sociological system. They are grouped together in the Erico-Pinion association. The black pine forests of Austria also belong here. In addition to the pine tree, the snow heather ( Erica carnea ) gives it its name . Warmth-loving shrub species such as common rock pear ( Amelanchier ovalis ), white whitebeam ( Sorbus aria ) and woolly snowball ( Viburnum lantana ) emerge under the umbrella of the mostly poor-growing pines . In the very species-rich herb layer, species with a distribution focus above the tree line (“dealpine” species) mix with species from the limestone grasslands and forest floor herbs. Typical species are box finial ( Polygala chamaebuxus ), ox-eye ( Buphthalmum salicifolium ), black-violet columbine ( Aquilegia atrata ) and orchid species such as the brown stendelwort ( Epipactis atrorubens ).
Riding grass pine forest
The limestone pine forests of the northern Alps and their foreland are summarized in the association of riding-grass-pine forest (Calamagrostio-Pinetum). It is typical that alpine species and moisture-loving species achieve higher proportions. It is named after the mountain riding grass ( Calamagrostis varia ).
Rock wolf milk black pine forest
The Euphorbio saxatilis-Pinetum nigrae is one of the two associations in the natural area of the black pine. This grows in the mountains of the Balkans north to the Karawanken and in a separate (“disjoint”) sub-area on the eastern edge of the Alps south of Vienna, mostly on the hard and weather-resistant dolomite. In addition to the species combination of the riding grass and pine forest, the rock spurge ( Euphorbia saxatilis ) occurs as a character species .
Blue-grass black pine forest
The blue-grass black pine forest (Seslerio-Pinetum nigrae) replaces the rock wolf milk black pine forest in lower elevations. In it, species from dry grassland and downy oak forests mix with dealpinous floral elements. The most common types of herb are lime blue grass ( Sesleria albicans ) and earth sedge ( Carex humilis ).
Lime dry pine forests of the low mountain ranges
In the southern German low mountain range, dry forests (the Scots pine) occur in small areas, sometimes only as a narrow band between blue grass grass and mixed beech or oak forests. In their species population, species of the limestone grasslands stand out. It is home to rare and colorfully blooming species such as panicle of grass lily ( Anthericum ramosum ) and pasque flower ( Pulsatilla vulgaris ). In terms of the species combination, the forests of the various low mountain ranges differ from one another, so that a large number of locally widespread associations have been described.
Sand and silicate pine forests
These occur on nutrient-poor, dry soils, either on sand or on shallow soils over acidic rocks. They are naturally widespread only in eastern Central Europe, in the subcontinental climate, but were able to expand their current area to northwest Germany through human support. It is not possible to differentiate between natural and secondary pine forests on the basis of their combination of species. The following associations are distinguished:
Hairline pine forest
The hairline pine forest (Peucedano-Pinetum, also Pyrolo-Pinetum), also called "steppe pine forest", is widespread in small areas in the subcontinental inland, mostly as a reforestation stage on abandoned dry grass. It grows on weakly acidic soils (pH around 5) and is very species-rich. The company is named after the mountain hairline ( Peucedanum oreoselinum ).
Crowberry pine forest
The crowberry pine forest grows on dunes near the coast of the Baltic Sea. Its soils are also only weakly acidic. Typical species are black crowberry ( Empetrum nigrum ), sand sedge ( Carex arenaria ) and moss-eye ( Moneses uniflora ).
White moss pine forest
The white moss pine forest (Leucobryo pinetum) grows on poor sandy or silicate soils with pH values seldom above 3. It usually has a thick layer of raw humus or dry mold made of hardly decomposed needle litter. Extensive moss coverings are typical of the forest type. In addition to the eponymous white moss ( Leucobryum glaucum ), various species of the genera Hypnum and Dicranum (e.g. Dicranum scoparium ), as well as Ptilidium ciliare and Pleurozium schreberi, are common. The herb layer usually consists of berry bushes ( bilberry Vaccinium myrtillus and lingonberry Vaccinium vitis-idaea ) or acid-bearing grass species such as the wire-smear ( Deschampsia flexuosa ). Many pine forests on sand show a similar combination of species.
Lichen-pine forest
The lichen-pine forest (Cladonio-Pinetum) grows on extremely poor locations and forms the dry and nutrient boundary of the forest here. Although there may be original locations on knolls or on steep slopes, it is mostly a result of soil degradation from overused forests or through reforestation of heather and open inland dunes. Soil type is a Podzol or Podzol-Ranker . The litter layer and the moss layer are much less developed than in the white moss-pine forest, but bush lichens (of the genus Cladonia , also of the Icelandic moss ( Cetraria islandica )) can determine the aspect. The lichen pine forest is a habitat type worthy of protection according to the Habitats Directive of the EU and is to be preserved through the designation of special protected areas (of the "Natura 2000" system).
Bog pine forests
The position of the bog pine forests in the plant-sociological system was controversial for a long time because they are very species-poor transitional stands, almost all of which can also occur outside the forest. Today most of the bog forests (i.e. also those with predominantly bog birch Betula pubescens ) are combined in one class Vaccinio uliginosi-Pinetea sylvestris. The bog pine forests and bog birch forests are even often included in the same association (Vaccinio uliginosi-Betuletum pubescentis Libbert) because apart from the predominant tree species they hardly differ. Bog pine forests grow on weakly dried out peat soils. This can be the drier "edge slopes" of the vaulted, living raised bogs as well as slowly growing bogs (under more continental climatic influences) or bog surfaces that are poorly drained by humans. The name-giving species is the bogberry ( Vaccinium uliginosum ), in addition to which there are peat mosses and wetness indicators such as rosemary heather ( Andromeda polifolia ) and cotton grass ( Eriophorum vaginatum ). Tree species can be both the Scots pine and the mountain pine (mostly in the subspecies bog pine). According to the Habitats Directive of the EU, the bog pine forest is a habitat type worthy of protection and should be preserved through the designation of special protected areas (of the "Natura 2000" system).
Pine forests
The pine is a common economic tree . Their share of the forest area in Germany is approx. 24%, which corresponds to approx. 2.5 million hectares of pine stands. This makes it the second most common tree species after the spruce. In many places, pine forests are particularly susceptible to damaging factors such as insect calamities and snow breakage. This is partly due to the fact that non-adapted ecotypes were used to establish the stand. The particular susceptibility to forest fires is particularly important in northern Germany, where hundreds of hectares of forest were destroyed in large damaging fires. It is assumed, however, that the Scots pine, like some North American pine species, is in a certain way adapted to forest fires and is indirectly promoted by them (because their competitors suffer even more).
The natural pine forests with their extreme soil conditions and the mostly poor-growing pines are of little economic value. Pine forests, which were artificially established instead of other types of forest, are much more important in terms of forestry.
literature
- Heinz Ellenberg : Vegetation of Central Europe with the Alps from an ecological, dynamic and historical perspective. 5th, heavily changed and improved edition. Ulmer, Stuttgart 1996, ISBN 3-8001-2696-6 .
- Fischer, Petra et al .: On the delimitation and situation of the FFH habitat type "Central European Lichen-Pine Forests" (91T0) in Germany. Nature and landscape 84 (6) (2009): 281–287 ( PDF )
- Heinken, Thilo: Sand and silicate pine forests (Dicrano-Pinion) in Germany: structure concept and ecology. Reports of the Reinhold-Tüxen-Gesellschaft. (2007) 19: 146–162. ( PDF )
- Heinken, Thilo: The natural pine locations in Germany and their endangerment. Contributions from the Northwest German Forest Research Institute (2008) 2: 19–41 ( PDF )
- Hölzel, Norbert: Synopsis of the plant communities in Germany. Booklet 1. Erico-Pinetea (H 6) Alpine-Dinaric carbonate pine forests. 1996
- Wagner, A. & Wagner, I .: Moor forests: characteristics and syntaxonomic position. Reports of the Reinhold-Tüxen-Gesellschaft (RTG) 2007, Volume 19: 164–174.
Web links
Individual evidence
- ^ Hesmer, Herbert & Fred-Günter Schroeder : Forest composition and forest treatment in the Lower Saxony lowlands west of the Weser and in the Munster Bay until the end of the 18th century. Forest historical contribution to the clarification of the natural composition of wood species and their artificial changes up to the early silviculture period. Decheniana , Beih. 11 (1963), 304 pp.
- ↑ Wendelberger, Gustav: The relict black pine forests of the eastern Alps. Vegetatio 11 (1963): 265-287 ( doi: 10.1007 / BF00303793 )
- ↑ Zukrigl, Kurt: The black pine forests on the eastern edge of the Alps in Lower Austria. Scientific reports from the Niederösterreichisches Landesmuseum 12 (1999): 11-20 (St. Pölten), PDF