hedge
A hedge (from Old High German : hegga = to cherish, enclose, to fence, ae. Hecg , English hedge , French. Haie , nndl. Heg , all of these terms have the same root word “ hag ”) is a linear growth (one or multi-row) dense, strongly branched shrubs . The syllable heck means to protect, guard, hedge and describes the demarcation of a place in general or through a hedge planting in particular. Place names with hagen or ha (a) g in the name are common.
History and use
As early as 57 BC During his campaign through Gaul , the Roman general Caesar complained about the hedges created by the Nervier tribe . In his report De bello Gallico it says: “In order to fend off the cavalry of their neighbors all the more easily when they come to them on raids, they saw down young trees and cause the many branches that grow in breadth, also with blackberry and thorn bushes planted between them that these fortifications form with the effect of walls, through which one not only could not get through, but could not even see through. Because the march of our army was stopped by these fortifications, the Nervians believed they should stick to their plan. "
Hedges, especially wall hedges , often owe their existence to earlier farming activities. In the Middle Ages , for example, hedges were used to fence the arable land within the three- field economy . Hedges were cut for fodder production or were cultivated like coppice forests. If the tree species of the hedge allowed it, hedges were also used to extract gerberlohe .
The typical box shape of the baroque garden hedges is reminiscent of the form of rural farming. The terms arbor and arcade also arise from the management of the hedges and trees that provide foliage. This type of management can be traced back to the transition from the hunter-gatherer culture to agriculture. The "deciduous grass" provided the food for the cattle in winter or when the summer heat (especially in the Mediterranean and Middle Eastern cultures) caused the grass to wither. Remnants of these peasant cultivations can be found on overgrown Schneitel trees that look like pollarded willows. In parts of Romania or the south-east of Turkey, cutting is still practiced today.
In some areas, mainly in western Germany, therefore, coppice forests are sometimes also referred to as hedges in the vernacular . In historical documents one also comes across expressions such as Lohhecken (see Lohwald ), Rodhecken , Kohlhecken and Backes-Heck . In the Birkenfeld (Hunsrück) area, forest operations that manage coppice were called "hedge societies". In the northern Saarland villages of Theley and Eiweiler , coppice forest is still cultivated by farms and referred to as hedge.
At the end of the High Middle Ages and in modern times , hedges were probably their longest extension. The division of brands in the second half of the 18th century brought large parts of the agricultural land into private ownership. Located on the parcel boundaries , the hedge made this ownership clear, served as a fence for cattle and as protection from human and animal intruders. Field stones and tree cuttings were often piled up at the boundaries of the parcels , from which reading stone bars and dead wood walls were created, which are part of a wall hedge.
In order to fill their functions permanently, they require regular care today because typical uses such as the Schneiteln and Lohmann and firewood absent. The sawn timber served as firewood and was in great demand during times of lack of wood. In this way, care was ensured by cutting or chopping , and the growth of woody plants that have good lifting capacity was encouraged. The rebuilding of the walls, but also the regular cut, the "putting on the stick" must be done so that the hedge does not become a row of trees. Thorny shrubs such as hawthorns are preferred for such border hedges, while particularly softwood species, such as elderberries , are fought in the hedge because they are shorter-lived and can lead to gaps in the hedge.
The low hedge also has a very long tradition as a design element in gardens . In single-family housing estates, this form takes on the function of the fence . Hedges can also have a support, trellis or fence as a basic structure, e.g. B. ivy or rose hedges.
Types of hedge
Near-natural hedges are divided into three different types of hedges based on their structure: low hedges, high hedges and tree hedges. Lower hedges are mainly composed of low shrubs that reach a height of two to three meters. High hedges consist of bushes up to five meters high in the center, which are framed on both sides by low shrubs. In addition to the layers of low and high hedges mentioned, tree hedges are characterized by the admixture of individual trees, mostly in the center. Tree hedges were created either through a lack of anthropogenic interventions, which enabled trees to grow through the hedge, or they were deliberately designed to this shape. This was done, for example, to give grazing cattle protection from the weather under the treetops.
There are also a number of other categorizations. For example, hedges are divided into grassland hedges and Gäuland hedges according to their history of origin . Grassland hedges are typical for northern Germany and owe their development to the targeted planting by humans. They should protect the valuable arable land from browsing and being represented by cattle. Such grassland hedges can be found, for example, in the Münsterland and Oldenburg , where the intensively used ash meadow was protected in this way .
Gäulandhecken, on the other hand, are typical for southern Germany. Gäulandhecken are spontaneously emerging woody plants that formed along steps and paths, piles of stones and bars. In contrast to the grassland hedges in northern Germany, these hedges stand individually; the hedges are not connected to each other because they could only arise where people shied away from the effort of clearing up emerging trees.
Wind protection strips are also called specially planted hedges to reduce wind erosion . They are mostly high hedges or tree hedges or just rows of trees. The non-natural decorative hedges are another type of hedge .
Ecological value
The hedge as a linear biotope
Hedges are one of the so-called line biotopes . They contribute to biodiversity and the networking of biotopes , particularly in heavily cleared landscapes with little or no forest and grassland .
The hedge itself offers very different location factors in the smallest of spaces , from damp and shady to sunny. It provides additional structures in the agriculturally used landscape. Due to its line shape, it serves as a “guideline” for many birds and many bats (compare also bird migration ). It is a good way for reptiles and amphibians to survive their migrations. The maximum biodiversity, especially of birds, is achieved at the expense of possible open land species with a lateral distance of 200 to 150 meters; a few larger hedges are more effective than many smaller ones. The critical composite distance for repopulation varies between five and ten kilometers. Ideally, the interruption of a hedge in the line should be as short as possible; the ultrasonic location of the bats, for example, only extends from 25 to 200 meters.
Building an ecologically valuable hedge
Ideally, the width of a hedge should be five meters as a strip of wood with a border of shrubs and weeds, the so-called fringing zone, about five meters wide on both sides. In the ideal case, the woody vegetation consists of taller woody wood in the core zone (trees as "overhanging") and smaller woody wood in the mantle zone (woody wood that can shoot). The hedge is then divided into:
- Hem zone - jacket zone - core zone - jacket zone - hem zone
The resulting overall breadth can rarely be achieved in reality.
The species composition of the woods varies depending on the region; Hawthorn , hornbeam , willow family , sloe , elder and common oak are particularly common (see also location (ecology) , potential natural vegetation ). In the transition to Staudensaum are wild roses , like the dog-rose , or blackberry frequently. In the seam zone, however, there are many species that are also found on a forest fringe: lilies , arum , Corydalis and wood anemone .
Near-natural decorative hedges made from local shrubs, especially from sloe, hawthorn and dog rose, offer a habitat for a rich fauna. In addition to the bush-breeding bird species already mentioned, rarer species such as red- backed shrike ( Lanius collurio ) can also appear under certain conditions , provided that the hedges and the surrounding area meet the high biotope requirements of this species.
Ornamental woody plants that are not native to the area are of minor importance for the local fauna. Even some of these trees are not usable for the native insects at all, in contrast to the native and site-appropriate species. Hedges that are remote from nature, for example those that mainly consist of conifers, can usually only be used as nesting sites by Eurocean bird species, such as the blackbird ( Turdus merula ). Lower hedges, which are mostly dominated by blackberries and comparable lower shrubs, basically have similar functions to near-natural hedges. However, due to their mostly very small, often only fringing surface area, they are somewhat inferior to other types of hedges in their ecological importance.
Importance of hedges for wildlife
Borderline effect
A high fauna diversity is achieved in near-natural hedges. This is caused by the so-called edge effect , which represents the transition zone between two different types of biotope (“ boundary line effect ”). Since this transition area is used by the animals of both types of biotope, this results in an extraordinary wealth of species. A multi-layered hedge provides a habitat for a large number of animals. Around 1500 species of hornbeam were found in Schleswig-Holstein, and around 900 species in field hedges in southern Germany.
In addition, there are also animal species that only live here (so-called fringe species). In terms of bird life, near-natural hedges can perform similar functions as the forest edges , so it is not surprising that many bird species occur in both woody structures. This applies in particular to the bush-breeding birds, such as various warbler species. Especially south-facing hedges with an extensive weed border are also home to a large number of insect species. Especially butterflies and grasshoppers should be mentioned here. In neighboring, intensively used agricultural areas, especially fields, such fringe structures represent important retreat and feeding biotopes for the animal world.
Biotope network
Linear, near-natural hedge structures fulfill not only the function of living space (e.g. for birds, amphibians, reptiles) but also functions of the biotope network . Such landscape elements often represent guidelines, for example for small mammals and insects, which are used during migration, spreading or foraging.
In the biotope network, for example with piles of stone piles , which, like in Brandenburg, are increasingly being placed under nature protection, the valuable ecological effect of the hedges is reinforced by the spatial contact with other species . Heliophile (sun-loving) species such as the cold- blooded sand lizard sunbathe on the sun-exposed side of piles of stone and dead wood . The latter applies to a greater extent to the hedge variants Knicks or wall hedges and Benjes hedges . It also contributes to the biodiversity of a hedge if there are ponds or small bodies of water near the hedge.
Wildlife
Spiders and insect species such as bedbugs , leaf beetles , weevils , butterflies , hoverflies , wild bees and longhorn beetles benefit from dead wood and the perennial border , or the weed border of a hedge . Many forest-dwelling species are represented, for example 94 percent of all species of ground beetles are forest-dwellers.
Hedges are also an important habitat for amphibians : decaying plant material is used, for example, by amphibians like the common toad for wintering. Hedges also provide an important habitat for birds, which find breeding and nesting opportunities, food through fruit-bearing shrubs and protection from the weather and enemies such as birds of prey ( bird protection hedges ). Depending on the species, they prefer to use the mantle and core zones.
In areas that are used intensively for agriculture, hedges are also very important for the field fauna, as these breeding, feeding and retreat areas are urgently needed in phases of land management (mowing, harvesting) and also wintering areas (after the fields have been harvested).
Hedges also provide additional habitat for mammals such as roe deer , brown hare , red fox , hedgehog , dormouse and bats . They are mainly found in the mantle zone and the core zone of a hedge.
Complementary habitat of birds
Birds are the most striking representatives of the hedge fauna. Using this example, the different areas of life and forms of use of a hedge can be shown:
- Breeding birds in the treetops and bushes (core zone and mantle zone of a hedge)
- Use of hedges as a preferred breeding area: puffy tit , tailed tit , rattle warbler , black warbler , buzzard , kestrel , red-backed shrike , gray shrike , field thrush , caplet , magpie , carrion crow
- Use of hedges as frequent breeding area: Spotted Flycatcher , Blackcap , Yellow Warbler , Wood Pigeon , long-eared owl , blackbird , chaffinch , greenfinch , goldfinch , serin
- Occasionally breeding in hedges: Dunnock , song thrush , honey buzzard , black kite , red kite
- Breeding birds in the plant thicket (mantle zone and fringing zone):
- Use of hedges as preferred breeding area: golden hammer , gray hammer , pheasant , partridge
- Use of hedges as a frequent breeding area: nightingale , field owl , swamp warbler , reed bunting
- Occasionally brooding in hedges: wrens , fitis , chiffchaff , robins , whinchat
In old high hedges with “overhangs” (large trees), a number of species that are not bound to hedge biotopes can also be found as breeding birds. These are, for example, the little owl , hoopoe and wryneck . In addition , great spotted woodpecker , pied flycatcher , swamp tit and nuthatch breed in such hedges.
Not as a breeding, but as a food area hedges are, among others, Siskin , Redpoll , Bullfinch , Hawfinch , Jay and winter by waxwing , Gimpel and Blaukehlchen used.
Influence of hedges on the landscape
Hedges have a stabilizing effect on the surrounding agricultural landscape, providing privacy and some noise protection. They themselves differ significantly from their surroundings in terms of sun exposure , evaporation , temperature , soil moisture , air humidity and wind exposure .
- A reduction in wind speed leads to a reduction in wind erosion in regions along the edge and to faster warming of the cold soil of moist locations such as marshes and bog soils ( peat ) in spring; on the other hand, cold air can accumulate on slopes ( not unproblematic in fruit growing ).
- Soil fixing is protection against water erosion and soil movement in hilly landscapes, in low and high mountains .
- Increased evaporation: Woods evaporate more water than herbaceous vegetation, in summer temperature maxima are reduced during the day and temperature minima are increased due to reduced radiation and latent warmth ; At the same time, the higher suction tension of the trees causes a water shortage for adjacent vegetation. Arable crops are affected when there is no fringe. The development of a dry hem is favored.
- Improvement of soil fertility: The fall of leaves and dying perennials in the edge of the hedge lead to an enrichment of the soil with raw humus in autumn . The ratio of the two elements carbon and nitrogen is improved in favor of the former and thus leads to an improved nitrogen fixation . However, farmers often fear on grassland locations that the fall of leaves in autumn could suppress forage grasses and favor a change in plant communities to more herbs. In the long term, there was a higher soil fertility on the broken soils, locations of former hedges, than on adjacent arable land.
- Shadows cast lead to a distinction between the sun-exposed and the shadow side. Less warming on the shady side is also often rated as negative, since, for example, grain ripens more slowly there than on sunny surfaces. This problem can be avoided in near-natural farming by caring for the weeds and creating strips of field margins.
- Privacy and noise protection, landscape: red deer , fallow deer and small game are increasingly looking for cover behind hedges in a structurally poor agricultural landscape. This privacy screen is also perceived as positive by people, for example in settlement areas and in "buffer zones". Richly structured hedge landscapes are often described with positive values such as “beautiful”, “idyllic” etc., viewed as ideal and often used for recreation. Several hedges standing one behind the other on traffic roads also offer a certain level of noise protection. On the other hand, it must be viewed critically that game scurries from cover to cover and is therefore often victims on roads that are greened with hedges.
The care of hedges
Today, hedges are hardly used for firewood. Therefore usually necessary to rejuvenate accounts cutbacks . The care of hedges must therefore be carried out consciously today, as overaged hedges in the sense of the biotope network only offer a home to a significantly smaller number of species. If the hedge and especially its border are not regularly and professionally cared for, it will develop into a series of large trees. The species-rich border shrubs without care; Larger trees grow, which are often delimbed because of adjacent uses: the border disappears.
The mowing of the herb edge at the hedge foot in summer leads to the destruction of the vegetation structure in the foot part, which is particularly worthy of protection, to the removal of the flower horizons and to the drying out of the hedge floor, so the maintenance measures mowing and pruning should be carried out in winter. If necessary, piles of dead wood should only be moved in early summer (May to June), as otherwise the amphibians will be severely disturbed in their refuge and winter quarters. The mowing can vary depending on profitability ( soil fertility are carried out of the location at a distance of twelve to 36 months).
To rejuvenate, the trees in the hedges must be cut back in sections, depending on the type of tree, at intervals of around ten to 20 years ("put on the cane"). The sections should not exceed a length of 150 meters or half the total length so that typical hedge dwellers can repopulate the biotope . With regard to the networking of the biotope, it is more advantageous to limit the pruning to shorter, non-contiguous sections of the oldest part of the hedge instead of clearing in one piece. If hedges are not pruned regularly over an extended period of time, radical pruning is required. For old hedges, this procedure should be spread over several years, starting with the hedge tip; the pages will be reduced in the next few years.
The time intervals between the maintenance measures on trees depend on the type of tree and the shape of the hedge. If a high hedge with overhangs is desired, longer time intervals should be set than with medium or low hedges. The pruning of trees that are capable of sprouting, such as willow plants, roses, hawthorn and elder, can be done every five to ten years; Hawthorn, hornbeam and alder stocks should be cut back less often, only about every ten to 20 years. But they can also be pruned more frequently, for example in the case of low hedges in the garden. Oaks should be able to grow unhindered for at least 20 years, depending on the vigor of the location. Consideration should also be given to dying and overaged trees, especially oak and common beech . They can form overhangs and standing dead wood and should therefore be partially preserved.
In many regions it is forbidden to clear, cut off or destroy hedges, hedges, bushes, reeds and reeds between March 1st and September 30th. In Germany, Section 39 of the Federal Nature Conservation Act regulates the ban. It protects valuable living quarters for birds. Many native birds are dependent on thick bushes in order to nest and breed undisturbed. Examples of late breeders are bullfinches , greenfinches and linnets .
New hedges
Appropriate selection of trees
Ever since the importance of hedges for species protection and the networking of biotopes was recognized, hedges have been created again in many places. Care should be taken to select trees that are appropriate to the landscape and the location. In the meantime, greater attention is paid to planting regional ( autochthonous ) plant material from a rich range of species and to bringing in the seeds of as many different mother shrubs and trees as possible in order to preserve the genetic diversity of the shrubs. In Bavaria, for example, the creation of hedges is only promoted if primarily native trees are used.
Maintenance of newly created hedges
In the case of newly created hedges on fertile arable soils, it can make sense to drain the soil in order to suppress fast-growing nutrient-loving species and to encourage a much more species-rich population of rarer specialists. The cuttings from the annual mowing and pruning must be removed over several years. Otherwise, the cut should remain in place to the emergence of scattered, Moder - and raw humus horizons and dead wood to promote.
New plant through Benjes hedges
For the creation of new hedges, so-called Benjes hedges have been propagated in particular since the early 1990s . The principle of the Benjes hedges is to build hedges not by replanting, but by introducing seeds from birds. For this purpose, pruning is laid in strips and after a herbaceous stage that is usually rich in nettles, bushes begin to grow. The advantage is that this form of the system is inexpensive and native seeds are brought in by birds. The disadvantage is that especially shrubs made from deciduous wood cuttings such as blackberries are becoming more popular. While a positive influence on the bird world, small mammals and insects can be achieved in this way, the Benjes hedge is rather irrelevant for botanical species protection. It has proven to be more sensible to supplement Benjes hedges with woodland plantings.
Endangerment of the hedges
Hedges in our cultural landscape were and are endangered by various causes. It is true that the consequences of forest and tree death through immission of air pollutants and the leveling of site factors through nutrient input from rain (nitrogen) did not leave them without a trace; In the last few decades, however, the intensification of use and changes in use have had a more direct and massive effect on the hedge population. The intensification of agriculture with increasing use of biocides , nutrient input ( eutrophication ) and land acquisition had a particularly destructive effect , also in the form of land consolidation . However, changes in use, for example the reallocation of agricultural land to building land and new construction or the widening of streets and paths with increasing visual and acoustic stimuli from road traffic, as well as the reuse and intensification of the use of fallow land, especially in residential areas in eastern Germany, are significant causes for their endangerment.
Other hazard factors, under the influence of which a hedge structure perishes more slowly, but no less effectively, contribute to the reduction of the hedge population. These are in particular insufficient or incorrect maintenance measures (need for order, traffic safety obligation), summer mowing, the removal of dead wood, grazing right up to the trees, which causes browsing damage , and the use of the surrounding fields right up to the hedges, which eliminates the strip of weeds, which should be at least four meters wide. As a result, the hedges also come into direct contact with drifted biocides and fertilizers .
Given all these negative influences, the information about lost hedges is no longer surprising. For Schleswig-Holstein, a reduction in the total hedge length from 75,000 to 50,000 kilometers was reported between 1950 and 1979; in North Rhine-Westphalia, destruction rates of 6.6 kilometers per year between 1953 and 1964 were given for a measuring table sheet ( Buldern ). During the period of intensive land consolidation proceedings between 1964 and 1972, the rate there rose to 9.2 kilometers per year.
All these calculations and information do not include the destruction of the many connected small structures and characteristic features of a hedge, which enhance its ecological effect. These include:
- the vertical shape of the hedge in question (variety in the height structure with particular emphasis on the low, but dense sections)
- the horizontal shape (width of the hedge, branches, etc.)
- the length of the hedge and the density of the hedge network (this is partly expressed in the destruction information).
- important additional structures such as species-rich grassland, old tree stumps, piles of stones or even ponds or other small bodies of water.
Hedges in the garden
In gardening and landscaping , cut hedges are a traditional and very old design element. They are already mentioned by the Egyptians and in ancient times. In the baroque and English landscape parks in particular , the hedge was created as a demarcation of the bosque or as a small ornament. In the garden , a large number of native and non-native trees are used for these very artificial plantings, which usually have to be cut several times a year.
There are three basic forms of hedge cutting (in the cross section of the hedge): the rectangular, the trapezoidal and the oval or egg-shaped cut. The rectangular cut is often used because it is the easiest to perform, but has the disadvantage that the hedge tends to shed near the ground due to lack of light, especially of course with light-hungry plants and high hedges. The other two cut shapes correspond to the teaching, allow better exposure of the lower leaves and result in a denser hedge growth.
Typical plants for the garden hedge that are native to Central Europe are: hornbeam , red beech , yew , cornel cherry , privet , hawthorn , barberry etc. However, non-native conifers such as the arborvitae are also often used. While these hedges can still serve as nutrient trees for animals, arborvitae and boxwood hedges have nothing in common with the free-growing hedges in the landscape.
The proper creation of hedges was already part of the teaching of the first German practice-oriented secondary school , which was founded by the theologian Johann Julius Hecker in Berlin in 1747 . Hecker had a school garden laid out, which delighted Hecker's Real pupil, the writer and publisher Friedrich Nicolai , in his memory even decades later. In 1750, the economic newspaper Leipzig Collections reported that a very special institution had been set up for lively instruction in plantation matters. For one has acquired a piece of land for a long lease and in fact lets the youth themselves show in recreation lessons what to watch out for when creating hedges, sowing, planting, grafting, oculating, etc. ...
An old special form of hedge systems are accessible labyrinths , which in Germany are called mazes .
When planting hedges on the neighboring property, the distances that are regulated in the respective state neighboring laws must be observed.
See also
literature
In alphabetical order by author
- Rudi Beiser: Secrets of the hedges: healing power, myths and cultural history of our shrubs. Eugen Ulmer, 2019, ISBN 3-8186-0726-5 .
- Hermann Benjes: The networking of habitats with Benjes hedges. Nature & Environment, Bonn 1998, ISBN 3-924749-15-9 .
- Eckhard Jedicke: Biotope protection in the community. Neumann, Radebeul 1994, ISBN 3-7402-0148-7 .
- Norbert Knauer: Ecology and Agriculture. Ulmer, Stuttgart 1993, ISBN 3-8001-4094-2 , pp. 96-114.
- Peter Kurz, Michael Machatschek, Bernhard Iglhauser: Hedges. History and ecology. Stocker, Graz 2001, ISBN 3-7020-0912-4 .
- Leipzig collections of economic, policey, cammer and financial items. Volume 7. Carl Ludwig Jacobi, Leipzig 1751, page 722.
- Georg Müller: Wall hedges, development - maintenance - new installation. BSH Verlag, 1989, ISBN 3-923788-16-9 .
- Georg Müller: Europe's field enclosures, wall hedges (curtains), hedges, field walls (stone walls / dry stone walls), dry shrub hedges, flexible hedges, wicker hedges, wicker fences and traditional fences. Neuer Kunstverlag, Stuttgart 2013, ISBN 978-3-944526-14-0
- Frank Schmelz: Linear, anthropogenic woody and fringing structures. Giessen 2001 (dissertation).
- Erika Schmidt: Old hedges as evidence of horticultural cultural achievements . In: Die Gartenkunst 18 (2/2006), pp. 337–342.
- Doris Schupp, Hanns-Jörg Dahl: Wall hedges in Lower Saxony. In: Information service for nature conservation in Lower Saxony. Hanover 1992, ISSN 0934-7135 .
- Peter Schwertner: Native biotopes. Natur-Verlag, Augsburg 1991, ISBN 3-89440-010-2 .
- Gerhard Siebels: On the cultural geography of the wall hedge. Rautenberg & Möckel, Leer 1954.
- Uwe Wegener (Ed.): Nature conservation in the cultural landscape, protection and care of habitats. Fischer, Jena 1998, ISBN 3-437-35250-4 .
- Dieter Wieland u. a :, green broken. Landscape and Gardens of the Germans. Raben, Munich 1983, ISBN 3-922696-43-0 (on this VHS film: Topo-graphie. Grün kaputt. Landesmediendienst Bayern 1983).
Web links
- Landscape hedge maintenance on hedgelaying.org.uk (English)
- Endangerment of the landscape hedges, hedge protection on heckenschutz.de
- Online lecture (41 pictures) about ecology, animals and plants in the hedge
- Hedge management in Münsterland
Individual evidence
- ^ Caesar: De bello Gallico , Book II, para. 17
- ↑ Stefan Bosch: Shelter for winter sleepers. In: NABU.de.
- ↑ The garden hedge - the all- rounder in the home garden ( page can no longer be accessed , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Leipzig Collections , p. 722; quoted from Weißpflug 1997
