Definition and taxonomic distribution
The Botany defined trees as perennial and woody seed plants containing a dominant shoot axis comprise, by secondary growth increases in size. These features differentiate a tree from shrubs , ferns , palms, and other woody plants . In contrast to their evolutionary predecessors, most trees also have much more differentiated leaf organs , which arise from multiple branched side shoots (long and short shoots). The trunk, branches and twigs lengthen each year by budding the end and side buds , lignify in the process and continuously increase in size. In contrast to the shrub, it is a special feature of the trees that the terminal buds dominate over the side buds ( apical dominance ) and thereby a predominant main shoot emerges ( acrotonia ).
Tree-shaped life forms occur in different plant groups: "Real" trees are the deciduous trees under the bedecktsamern and the tree-shaped naked plants , which include conifers such as conifers , but also ginkgo biloba (as the only remaining representative of the ginkgo plants) and numerous representatives of the pinnate nudibranchs (Cycadophytina). The most peculiar tree is probably the Welwitschia mirabilis found in Namibia , the trunk of which remains in the ground. In addition, the palms and tree ferns can also develop a tree-like shape. However, these groups have no real wood (secondary xylem ) and are therefore not considered trees. The dragon tree ( Dracaena ) occupies a special position . Although this belongs to the monocot family, it has an atypical secondary growth in thickness .
Tree-like forms are mainly found in around 50 higher plant families . In contrast, the tree form with missing algae , moss , lily plants , Iridaceae , Hydrocharitaceae , orchids , Chenopodiaceae , Primelgewächsen and usually also in the Convolvulaceae , bell flowers plants , Cucurbitaceae , Umbelliferae , Saxifragaceae , Papaveraceae , Ranunculaceae or Caryophyllaceae .
Trees occur today within the Nacktsamer (Gymnospermae) on the one hand in the form of the Ginkgoopsida with the species Ginkgo , on the other hand the needle-leaved Nacktsamer ( Coniferopsida , "conifers"). Dominated the species especially of the order Pinales with the families Pinaceae ( spruce , pine , fir , Douglas fir , larch , gold larch ), Cupressaceae ( cypress , cypresses , bald cypress , trees of life , junipers , redwoods ), Podocarpaceae ( Podocarpus , dacrydium ) Araucariaceae ( araucarias , kauri trees ), Taxaceae ( yew trees ) and Cephalotaxaceae ( head yew trees ).
Many tree species are also found within the angiosperms (angiosperms). The different subclasses have produced different types of deciduous trees. The most important of these are the beech family ( Fagaceae ), which, in addition to the beech trees ( Fagus spp.), Also include the oaks ( Quercus spp.) And chestnuts ( Castanea ). Also important are the birch family ( Betulaceae ) with the birch and alder as well as the nut trees ( Juglandaceae ), the elm ( Ulmaceae ) and the mulberry family ( Moraceae ). The rosids include the linden trees from the mallow family , the fruit trees from the rose family (Rosaceae) and the legumes ( Fabales ) with very numerous, especially tropical species. In addition to the genus Dalbergia (rosewood trees), the genus Robinia also belongs to this group. The cedar family ( Meliaceae ) with the genera Entandrophragma (mahogany trees) and Cedrela as well as the Dipterocarpaceae family with the genus Shorea (Meranti, Bangkirai) are economically significant .
The special characteristics of trees
Morphology of tree-shaped life forms
Tree-like life forms show a wide range of variations in their structure ( morphology ). The term tree is associated with the structure of the tree crown, tree trunk and tree roots. The tree-like ferns and most palms have simple trunks that do not form branches, but rather tufted, often pinnate leaves. Above all, they show no secondary growth in thickness and are therefore not real trees.
In real trees, the future tree trunk grows from the shoot of the seedling plant through lengthwise and secondary growth in thickness: The shoot continues to form upright at the top due to the constantly renewing peak bud and becomes a straight tree trunk that extends all the way to the highest crown tip ( Monopodium ). Growth substances ( auxins ) formed in the top bud suppress the activity of the side buds. In many tree species, this dominance of the main shoot diminishes with age and a typical, branched deciduous tree crown forms.
In the case of other woody plants such as the beech or the hornbeam , a sub-terminal side bud takes the lead ( sympodium ). In the case of trees, an upright "apparent axis" ( monochasium ) is created. Later on, the dominance of the leading bud diminishes and further side buds develop into stronger branches that eventually form a crown. This usually happens earlier than with trees with monopodial growth.
Shrubs, on the other hand, are characterized by the complete lack of apical dominance. Numerous soil-borne side shoots form a widely branched habit.
In woody plants, a shoot section (annual shoot) forms on the growth axes during the vegetation period, the beginning of which can be recognized for a long time by the narrow, ring-shaped leaf scars of the former bud scales. Another shoot after the vegetation period is called the St. John's shoot (prolepsis). Tropical species tend to sprout multiple times.
The age of a branch can be determined from the number of annual shoots and the degree of branching. This age determination is made more difficult in numerous species (for example spruce or fir) and regularly in older trees due to the development of so-called preventive shoots that sprout from "sleeping" buds. The regular formation of preventive instincts is called reiteration (read: re-iteration). These repetitive shoots are used to renew the crown and give trees the opportunity to replace aging branches and to react to stress (snow breakage, insect calamities).
Trees can reach an age of several hundred years, in certain locations even several thousand years. The oldest tree in the world (as of 2008) is the 9550-year-old Old Tjikko spruce in the Fulufjället National Park in the Dalarna district of central Sweden . Three other "generations" (375, 5660 and 9000 years old) with identical genetic material were found under this spruce. The number of spruce trees, which are over 8,000 years old, is estimated to be around 20. This means that the spruce is around twice as old as the North American pines, which at 4,000 to 5,000 years have been the oldest living trees. The proven oldest trees in Central Europe are dated to around 600 to 700 years.
If the tree grows under climatic conditions that fluctuate in the annual rhythm , an annual ring is created during the vegetation period. With the help of these rings, the age of a tree and its growth conditions in the individual years can be read. The dendrochronology uses this to date old wood and to reconstruct the climate of a region up to several 1000 years.
Its development brings numerous problems and damage to the tree. This mainly includes:
- Fungal attack,
- Insect damage,
- Windbreak (parts of trees break off),
- Windthrow (the tree is levered out of the ground with the roots),
- Snow breakage (parts of trees break off under heavy snow loads),
- Lightning damage (trunk parts are blown off),
- Frost (drought damage through transpiration in frozen ground, trunk cracks).
In the case of young trees, in particular:
Some major diseases that can affect trees are fire, cancer, rust, powdery mildew , red rot, white rot, brown rot, and resin flux. Deformities on trees include the measles heads , witch brooms or weather bushes , as well as galls .
Structure of the tree trunk
A cross-section through a tree trunk, the lignifying main axis (caulom) - called the shaft in dendrology , shows different zones. Innermost are the existing primary tissue from Mark and the dead heartwood . Certain tree species (e.g. beech, ash) optionally develop a false core , which differs in properties from real heartwood. Farther out is the sapwood , which is used for conduction and storage and, in so-called heartwood trees, usually stands out clearly in color from the heartwood. This is very clearly visible in the oak, yew and robinia. The spruce has a colorless core ( frosted wood ).
The outermost layer is the tree bark . It consists of the bast layer , which transports nutrients dissolved in water, and the bark , which protects the trunk from environmental influences (UV radiation, heat, mechanical and biotic damage).
In gymnosperms and dicotyledons, the cambium is located between the bast layer and the wood . This growth layer forms wood ( xylem ) on the inside and bast ( phloem ) on the outside through secondary growth in thickness . The wood is characterized by the storage of lignin in the cell wall. This stiffens the cells and forms a firm permanent tissue. The secondary growth in thickness, the lignification of the wooden cell wall and the reproduction by seeds gave the trees in most biomes of the earth an advantage over other plants and led to the development of large forests there. Exceptions are the deserts, the arctic tundras and the central continental steppes.
With regard to the internal construction of the log to the soft monocots belonging palms of the real trees from considerably. In the former, the vascular bundles are scattered in the base tissue, which is why there is no cambium ring, no wooden cylinder, and thus no continuous secondary growth in the thickness of the trunk. In the case of belonging to the dicotyledons or gymnosperms trees of the strain has already in the earliest youth as a thin stem is below the bark located circle of vascular bundles , of the cortical area of the inner Mark separates. This vascular bundle ring represents the wood in its inner half adjacent to the pith and the bast in the outer part adjacent to the bark ; the cambium ring extends between the two. This is formed from tender, sap-rich, constantly dividing cells and, through its ongoing cell reproduction process, enlarges the tissues adjacent to it on both sides. Every year, a new zone of wood fabric is created on the outside of the wooden ring, creating the annual rings of the wooden body that is strengthened in this way, which can be perceived as concentric lines on the trunk cross-section. On the other hand, the bast lying further outside also receives an annual, albeit much smaller, increase on its inside. In this way the permanent thickening of the trunk and all branches as well as the roots comes about.
The trees also differ from one another in their root formation. In addition to the genetic definition, the requirements for anchoring the tree in the ground as well as the need to supply the plant with water and nutrients control the intensity and type of root growth. Depending on the shape of the rhizome, one speaks of taproot , shallow root or heart root . In the taproot, the main root grows vertically down into the ground, which is particularly characteristic of the oak . Shallow soils and high lying bedrock or groundwater favor z. B. the formation of shallow roots. Dry soils favor the formation of tap roots. The predominant mass of the root stock in the trees is not made up of the woody parts of the roots, but rather the fine roots associated with a mycorrhiza . In the soil, many roots combine symbiotically with fungal mycelia. Trees get minerals like phosphorus from mushrooms, while mushrooms get the carbohydrate products of photosynthesis from trees. The mushrooms can connect different trees together, and a network is formed that carries nutrients and signals. The total root mass often comes close to the mass of the above-ground parts of the plant. In monocot tree-like life forms, the trunk ends near the ground surface and a root system ( homorhizia ) develops .
Young adventitious roots are usually found on old trees, replacing old, ineffective roots. In some tree species, roots close to the surface form what is known as root brood , a form of vegetative reproduction . Root trimming as a result of construction work can cause parts of the roots to die off and lead to the penetration of wood-destroying fungi into the tree. This is the most common cause of irreparable tree damage in urban areas.
Trees have deciduous leaves or coniferous leaves that either remain on the tree for several years (evergreen species) or are shed at the end of a growing season (deciduous species). In between there are the semi-evergreen species, which lose only part of their leaves at the end of a vegetation period, but then replace the previous year's when new growth occurs. With the exception of the genera larch ( Larix ) and golden larch ( Pseudolarix ), the conifers are evergreen species. In the boreal and high-montane biomes of the northern hemisphere, the evergreen conifers have established themselves as they can begin assimilation at the beginning of the vegetation period when the temperature is sufficient, without first having to form assimilation organs like the deciduous tree species.
The shape of the leaves ( foliage ) is an important determinant. Arrangement, shape, size, color, veins and teeth as well as haptic properties can be used for differentiation. The (leaf) buds of the tree are no less useful for differentiating in winter conditions . A clear taxonomic identification of the species is only possible on the basis of the flowers or fruits. Some trees have thorns . These are either short branches that end with a thorny tip ( hawthorns , wild forms of fruit trees ) or they are spiky stipules such as those of the common robinia .
A European deciduous tree has an average of 30,000 leaves, which together have an enormous transpiration capacity. On warm summer days, the tree can evaporate several hundred liters of water. Example of an 80-year-old European beech tree standing alone : At this age, the tree is 25 meters high, and its treetop with a diameter of 15 meters covers an area of 160 m². In its 2,700 m³ volume there are 800,000 leaves with a total leaf surface of 1,600 m², the cell walls of which add up to an area of 160,000 m². This beech tree consumes 2.352 kg of carbon dioxide , 0.96 kg of water and 25,435 kilo joules of energy per hour (this is the energy stored in the form of glucose, the radiated solar energy is about seven times greater); In the same period of time, it produces 1.6 kg of glucose and, with 1.712 kg of oxygen, covers the consumption of ten people. The 15 m³ of wood in the tree weighs 12,000 kg dry, 6000 kg of which is carbon .
The blossoms of trees from temperate latitudes are sometimes relatively inconspicuous; in some taxa individual petal circles are reduced. Some temperate tree species have unisexual flowers. The flowers of both sexes sit either on the same tree (single-sexed, for example oak , beech , hornbeam , birch , alder and walnut ) or on different ones (double-sexed), so that one has to distinguish between male and female trees (among others Willows and poplars ). Other trees such as fruit trees, horse chestnut and many trees the warmer climates have hermaphroditic flowers that both dust and carpels formed.
Fruit and seed formation
The fruit and seed formation shows less peculiarities. Most trees ripen in the summer or autumn of the same year; only in the case of the pine species do the seeds and the cones containing them become fully developed in the second autumn after flowering. The fruits are mostly nut-like with a single formed seed, or they consist of several solitary, nut-like parts, as with the maples . Juicy stone fruits , also with one or a few seeds, can be found in the fruit trees, capsules with numerous seeds in the willows and poplars.
Development of tree-shaped plants in the history of the earth
The prerequisites for the emergence and spread of the trees were:
- the development of the corm (differentiation between leaf, shoot and root) as an organizational form of higher plants,
- the development of the seed as a method of reproduction,
- the development of lignin for the formation of permanent tissue,
- the development of secondary growth in thickness for the formation of perennial organisms.
The precursors of the trees are known from the carbon . They belonged to the horsetail family , the bear moss family and the ferns . They had lignified trunks that also showed secondary growth in thickness. Fossil genera are for example Lepidodendron and Sigillaria . The compacted sediments of these forests form the coal .
The further evolution of the plants produced the seed plants in the Permian . The Nacktsamer were the first trees to spread rapidly, reaching their greatest biodiversity in the Triassic (about 200 million years ago) until they were replaced in importance by the angiosperms in the Paleogene (about 60 million years ago) . Of the known 220,000 flowering plants, around 30,000 are wood species, so that about every eighth flowering plant is a tree or shrub. Most tree species are among the angiosperms (angiosperms). The gymnosperms (Nacktsamer) comprise only about 800 species, but still cover a third of the earth's forest area.
The global distribution of tree species was primarily shaped by climatic conditions and continental drift . For example, while the beech family ( Fagaceae ) is a typical family in the northern hemisphere, the Podocarpaceae family, for example, is predominantly found in the southern hemisphere. Today's natural species distribution was strongly influenced by the Quaternary Ice Ages . The simultaneous penetration of the Scandinavian and Alpine glacial masses of Europe has led to the displacement of numerous species and has caused a conspicuous species poverty in Central Europe compared to North America. For example, the only spruce species native to the montane regions of Central Europe, the common spruce ( Picea abies ), contrasts with numerous spruce species on the North American continent.
As with all plants, metabolism and growth in trees are subject to both endogenous (genetically determined) and external influences. The latter include above all the location conditions, the climate and the competition with other organisms or their harmful effects. During the vegetation period, the tips meristeme and the cambium ensure a constant increase in length and thickness. The beginning and end of the vegetation period are determined by the weather and the availability of water or the length of the day, depending on the tree species. The growth is controlled by phytohormones and the accumulation of biomass is specifically optimized. Trees are able to adapt to changing growth conditions and to create directional strengthening, guiding, storage or assimilation tissues .
The production of new tissue with the secondary growth in thickness and the creation of new annual shoots causes a tree to constantly renew itself from the inside out. The American tree biologist Alex Shigo developed the concept of compartmentalisation, which sees the tree as an ensemble of interacting compartments. Unlike animals and humans, the tree reacts to injuries through isolation reactions and the abandonment of the encapsulated compartments ( CODIT model). It also optimizes its shape through adaptive growth.
Computer modeling by the Karlsruhe physicist and biomechanic Claus Mattheck was able to show that trees strive for a mechanically optimal shape through adaptive growth and, for example, avoid notch stresses in branches, so that the risk of fractures is minimized. These findings have led to optimizations in mechanical engineering, among other things.
The water is transported in the conifers by the tracheids , in the deciduous trees by the more effective vessels (pores). In the case of deciduous trees, the latter are either scattered (e.g. beech, maple, poplar) or in a ring (e.g. oak, elm, ash) in the annual ring . For example, an oak pore with a diameter of 400 µm can transport 160,000 times more water than a softwood tracheid with a diameter of 20 µm in the same period of time.
According to the predominantly represented teaching, the water transport of the trees works by suction stresses in the conducting tissues as a result of evaporation on the stomata of the leaves ( cohesion theory ). Tree heights of over 100 meters must be overcome, which according to this theory is only possible with enormous pressures. Critics of this doctrine claim that even at significantly lower altitudes, the suction tension should lead to the tearing of the water thread in the capillaries. What is certain, however, is that sugar is mobilized in the storage cells in spring and water flows from the roots due to the osmotic pressure built up. In the process, nutrient salts (especially K, Ca, Mg, Fe) dissolved in the soil water are absorbed by the tree. Only after the leaves have differentiated are the assimilates produced in the crown transported down the trunk via the bast and are available for growth in thickness. The ring-pored deciduous trees are an exception, in which the first early wood pores are formed from the reserve materials formed in the previous year .
The sweet “tree sap” was tapped by people by cutting into the bark and then boiled down to make syrups , for example maple syrup or the sap of the manna ash . Palm sugar or palm syrup, however, is an extract from the sap of the nipa and sugar palm (subfamily Arecoideae), agave syrup comes from the "juice" of the perennial agaves , birch sugar was originally obtained in Finland directly from the birch bark .
The hydrology or soil ecology differentiates between the precipitation , which hits the ground in the area of the tree crown ( canopy passage ) and the portion that flows down the trunk ( trunk runoff ). Some of the precipitation evaporates directly from the tree ( interception ) and does not reach the ground.
Wherever trees find sufficient light, warmth and water, they form forests. According to the FAO, 30 percent of the earth's mainland mass was forested in 2000 . Forest trees bind between 60 and 2000 tons of organic material per hectare, making them the largest biomass storage facilities on the continents. The total amount of wood mass accumulated in forests worldwide in 2005 was 422 gigatons. Since about half of the wood substance consists of carbon , forests are the largest carbon sinks in the biosphere after the oceans and are therefore important for the CO 2 balance of the earth's atmosphere .
The competition for resources associated with the formation of trees leads to an adaptation of the habitus compared to the free-standing specimens (solitaires). Natural branch shedding within the shadow crown and the shifting of assimilation into the light crown are optimization reactions of the trees, which lead to a tall, slender growth with small crowns and often to hall-like stands (for example old beech stands).
The current expansion and species composition of the forests is strongly influenced by human economic activity. The transition from the hunter-gatherer culture to agriculture went hand in hand in the densely populated regions with the pushing back of the forests. At first, trees were primarily useful for people as firewood ( coppice forest management ). In the course of development, the extraction of timber from high forests became more and more important. This development continues. According to the FAO, 46 percent of the world's logging (3.2 billion m³) was still being used as firewood at the end of the 1990s; in the tropics it was even 86 percent. The extensive destruction of forests in Central Europe during the Middle Ages has led to the introduction of the principle of sustainable forest management in modern times , according to which only as much wood can be removed as can grow back.
Distribution centers, diversity
The primary forests of the humid tropics have the greatest biodiversity of all forest types. Important tropical families are the spurge family (Euphorbiaceae), soap tree plants (Sapindaceae), Bombacaceae , Byttnerioideae (to the Malvaceae ), meliaceae (Meliaceae), legumes (Fabaceae), Caesalpiniaceae , Verbenaceae , Sterculiaceae , Dipterocarpaceae and Sapotaceae .
In the subtropical zone you can find trees among the evergreen myrtle family (Myrtaceae) and laurel family (Lauraceae) as well as silver tree family (Proteaceae), which are joined by other evergreen trees in the warmer, temperate zone, such as the evergreen oaks , pomegranate trees , orange and lemon trees and olive trees .
In contrast, the deciduous trees are predominant in the temperate zone . Here forests of oak , beech and hornbeam are characteristic. The deciduous trees native to Central Europe include maples , birches , beeches , oaks, alders , ash trees , linden trees , whitebeams , poplars , elms and willows . Typical conifers are the spruce , pine , larch , fir and yew trees . Tree species that occur frequently in Central Europe and are not originally native to this area are the common robinia , walnut tree and many fruit trees . The list of trees and shrubs in Central Europe provides a detailed list .
And although coniferous woods already appear here in contiguous forests, the coniferous forests only become predominant in the subarctic ( boreal ) zone, where the deciduous trees are gradually being displaced. Species diversity as well as the height of the trees decrease with increasing approach to the Arctic Circle . Oak , linden , ash , maple and beech can only be found on this side of the 64th degree north latitude in Sweden . Beyond this latitude, the tree vegetation consists mainly of spruces and firs , which in contiguous forests to the northeast still extend beyond 60 degrees, and of birches , which in contiguous stands extend almost to 71 degrees north, and partly of alders and Pastures .
The height above sea level also has a significant influence on the spread and height of the trees (depending on the geographical latitude). In the Andes there are Polylepis trees up to an altitude of 5000 m . Below 30 degrees north latitude, where the snow line is 4048-4080 m, in the Himalayas , north of India , groups of trees consisting of oak and spruce are still 3766 m high. Likewise, in Mexico , below 25–28 degrees north latitude, the mountains up to 3766 m high are covered with spruce and up to 2825 m high with Mexican oaks. In the Alps of Central Europe, wood growth ends at an altitude of 1570 m, in the Giant Mountains at 1193 m and on the Brocken at 1005 m. Oaks and firs still stand on the Pyrenees up to a height of 1883 m; in contrast, the spruce grows on the Sulitelma in Lapland , at 68 degrees north latitude, barely at a height of 188 m, the birch barely at a height of 376 m.
Trees and people
The scientific study of trees (trees) is dendrology . Planting trees in a systematic or geographical arrangement, the arboretums , are used for observation and experimentation purposes. Trees can be propagated vegetatively , i.e. by parts of plants, or generatively by sowing . In tree nurseries , trees and shrubs are specifically selected, grown and multiplied. In addition to their forestry use, trees are also widely used in gardening and landscaping . With tree care , a separate profession has developed for the preservation and professional treatment of trees in urban regions.
"No other creature is so diverse, so closely linked to the fate of humanity as the tree."
This is what the historian Alexander Demandt wrote and has dedicated an extensive work to the tree with Over all Wipfeln - The Tree in Cultural History . For him, cultural history begins with the fire that lightning struck the trees and with the tools for which wood has always been indispensable.
In addition to the important function of trees in the design of cultural landscapes, the use of wood in particular accompanies human development. Apart from the use of firewood, which is still widespread, especially in developing countries, wood is a versatile building and material, the amount of which is produced far in excess of the amounts produced by steel , aluminum and concrete . Wood is therefore still the most important building and material worldwide; Accordingly, trees are an important source of raw materials.
In addition to the use of wood, trees are primarily used to obtain flowers, fruits, seeds or individual chemical components ( turpentine , sugar , rubber , balsams , alkaloids and so on). In the forestry of industrialized countries such uses would play a subordinate role. Only fruit growing as part of agriculture is an important economic factor in many regions. The cultivation takes place in the form of plantations . Quality fruits are usually by budding or grafting refined. This is done by using selected types of fruit, whereby the known and desired properties of the fruits of a type of fruit are transferred to a young tree. On the other hand, the use of orchards , which used to characterize the landscape in many areas of Central Europe, has decreased.
According to this meaning, a diverse tradition is associated with the tree. This ranges from the tree that has to be planted for the birth of a child, to the maypole , which in some regions is worshiped on the night of the first of May for loved ones, to the fairground tree and Christmas tree under which one celebrates, and the topping-out tree on the roof truss of a newly built house to the tree that will be planted on the grave. Nations and peoples are assigned certain trees that are characteristic of them. Oak and linden are typical “German” trees. The birch symbolizes Russia, and the baobab is considered the typical tree of the African savannah. Law was pronounced under the court linden tree (see also → Thing ) and celebrated under the dance linden tree.
Since 1989, the tree of the year has been determined every year in October for the following year , initially by the “Verein Baum des Jahres e. V. ", since 2008 by the" Dr. Silvius Wodarz Foundation ”and through its advisory board, the“ Kuratorium Tree of the Year ”(KBJ). In 2000 the foundation chose the ginkgo tree ( Ginkgo biloba ) as the tree of the millennium as a memorial for environmental protection and peace.
Mythology and religion
Numerous myths tell of a tree of life or world tree that represents the world axis in the center of the cosmos. Among the Nordic peoples, for example, it was the world ash Yggdrasil , under whose crown the sir held their court. Thus the tree plays a role in the myths of the peoples as the tree of life like the sycamore in the Egyptians or in Jewish mythology. Celts , Slavs , Germanic peoples and Balts once worshiped trees in groves of gods, and the felling of such idolatrous trees is the subject of numerous legends that tell of the proselytization of Northern and Central Europe.
In many ancient cultures and religions, trees or groves were worshiped as the seat of gods or other supernatural beings. Such ideas have been preserved to this day as a sunken religious asset. The peach tree in China is considered the tree of immortality. The bodhi tree , under which Buddha found enlightenment, is a symbol of awakening in Buddhism .
Trees are also mentioned again and again in the Bible . Tanach as well as the New Testament name different tree species, such as the olive tree or the fig tree , with whose relatively large leaves the first human couple Adam and Eve covered their nakedness after their fall according to Genesis 3: 7 . In the first book of Moses , the Genesis , it is reported in chapter 1 in verses 11 and 12 that God brought the trees and especially the fruit-bearing trees in his creation of the world. Two trees play a decisive role in the creation story: the tree of life and the tree of the knowledge of good and evil .
The tree has a special meaning in Christian iconography . The tree as a symbol of the fall of man, around whose trunk a snake winds, is often juxtaposed with the wooden cross as a symbol of redemption. A dry and a green tree symbolize the old and the new covenant in the dogma allegories of the Reformation period . In the plant symbolism, different tree species as well as their leaves, branches and fruits have a special meaning. The acacia indicates the immortality of the human soul, the olive tree indicates peace and is an ancient Marian symbol for the Annunciation to Mary. The cone of the pine indicates the life-giving grace and power of God, the holly , from whose branches the crown of thorns was made, according to legend , to the passion of Christ .
In the history
Memorial trees are trees that were planted to commemorate an event or in memory of a person.
- The tallest tree in the world is the " Hyperion ", a coastal redwood tree ( Sequoia sempervirens ) in the Redwood National Park in California with a height of 115.5 meters.
- The tallest tree in Germany, perhaps even on the continent, is the "Waldtraut vom Mühlwald", a 63.33 meter (as of August 18, 2008) high Douglas fir ( Pseudotsuga menziesii ) in the Freiburg-Günterstal arboretum , part of the Freiburg city forest.
- The most voluminous tree in the world is said to be the General Sherman Tree , a giant sequoia in Sequoia National Park , California, USA: volume about 1489 cubic meters, weight about 1385 tons ( US ), age about 2500 years.
- The thickest tree is the " tree of Tule ", a Mexican bald cypress ( Taxodium mucronatum ) in Santa María del Tule in the Mexican state of Oaxaca . Its diameter at the thickest point is 14.05 meters.
- The oldest trees in relation to a single tree trunk are - according to a guaranteed annual ring count - more than 4800 years old long-lived pine ( Pinus longaeva , formerly regarded as a variety of the Common Pine ) in the White Mountains of California.
- The oldest tree in relation to the living organism is the American trembling aspen colony " Pando " in Utah, USA, whose age is estimated to be at least 80,000 years. Again and again new, genetically identical tree trunks sprout from the roots ( vegetative reproduction ), which are around 100–150 years old. In an individual of the species " Huon Pine " in Tasmania, which is at least 10,500 years (perhaps even 50,000 years) old, the oldest tree trunk is about 2000 years old. The oldest trees in Europe are in the Dalarna province in Sweden. In 2008 about 20 Norway spruces were dated to over 8,000 years, the oldest to 9,550 years. The individual tree trunks die off after about 600 years and are rebuilt from the roots.
- The hardest trees are the Dahurian larch ( Larix gmelinii ) and the East Asian dwarf pine ( Pinus pumila ): They withstand temperatures down to −70 ° C.
- The Dahurian larch is also the tree species that can survive furthest north : 72 ° 30 'N, 102 ° 27' E.
- The trees at the highest altitude are found at an altitude of 4600 meters in the eastern Himalayas in Sichuan , where the scalloped fir ( Abies squamata ) thrives .
- The wood of the lowest density is that of the balsa tree .
- Trees that could previously colonize bare areas , so-called pioneer plants , are, for example, certain types of birch , willow and poplar .
- In bonsai art one tries to imitate the image of an ancient and raised tree in a small shell.
- The oldest tree species on earth and probably the oldest living fossil in the plant world is the ginkgo tree ( Ginkgo biloba ).
- Germany's oldest trees. Documentation, 45 minutes. A film by Jan Haft . Production: Bayerischer Rundfunk, broadcast on April 23, 2007.
- Planet earth : forest worlds . Documentation, 45 minutes. A film by Alastair Fothergill . Production: BBC, 2006, German first broadcast: ARD , on March 26, 2007.
Introductions / overviews
- Horst Bartels: Wood science. Introduction to dendrology. 1st edition. Ulmer, Stuttgart 1993, ISBN 978-3-8252-1720-4 (excellent introduction, consisting of a systematic part and a dictionary of dendrology).
- Helmut Josef Braun : Construction and Life of Trees. 4th edition. Rombach, Freiburg 1998, ISBN 978-3-7930-9184-4 (generally understandable and richly illustrated introduction to tree anatomy and physiology).
- Alex L. Shigo : The New Tree Biology. Technical terms from A to Z. Haymarket Media Verlag Bernhard Thalacker, Braunschweig 1990, ISBN 978-3-8781-5022-0 (illustration of the compartment concept and the wound reactions of trees, numerous illustrations).
- Claus Mattheck : Design in nature - the tree as a teacher. 4th edition. Rombach, Freiburg im Breisgau / Berlin 1997, ISBN 978-3-7930-9470-8 (introduction to tree mechanics).
- Peter Schütt , Hans Joachim Schuck, Bernd Stimm: Lexicon of forest botany. Morphology, pathology, ecology and systematics of important tree and shrub species. 1st edition. ecomed, Landsberg / Lech 1992, ISBN 978-3-609-65800-1 .
- Dietrich Böhlmann: Why trees don't grow into the sky. An introduction to the life of our trees. Quelle & Meyer, Wiebelsheim 2009, ISBN 978-3-494-01420-3 .
- Andreas Roloff , Andreas Bärtels: flora of woody plants, determination, properties and use. 2nd Edition. Ulmer, Stuttgart 2006, ISBN 3-8001-4832-3 (The current and at the same time the most comprehensive woody flora, with a winter identification key by Bernd Schulz).
- Ulrich Hecker: BLV Handbook Trees and Shrubs. BLV, Munich 1995, ISBN 3-405-14738-7 (identification book and reference work in one).
- Alan Mitchell, John Wilkinson, Peter Schütt: Parey's Book of Trees. Conifers and deciduous trees in Europe north of the Mediterranean. ( The Trees of Britain and Northern Europe ). Paul Parey, Hamburg / Berlin 1987, ISBN 3-490-19518-3 .
- Alexander Demandt : Above all tops. The tree in cultural history. Böhlau, Cologne 2002, ISBN 3-412-13501-1 .
- Doris Laudert: The myth of the tree. What trees mean to us humans. History, customs, 30 tree portraits. BLV, Munich 1998; New editions there in 1999 and 2001, ISBN 3-405-15350-6 .
- Graeme Matthews, David Bellamy: Trees. A trip around the world in fascinating photos. ( Trees of the World. ) BLV, Munich 1993, ISBN 3-405-14479-5 .
- Gerd and Marlene Haerkötter: The secret of the trees. Legends - history - descriptions. Eichborn, Frankfurt am Main 1989, ISBN 3-8218-1226-5 .
- Fred Hageneder: The wisdom of the trees. Myth, history, healing power. Franckh-Kosmos, Stuttgart 2006, ISBN 3-440-10728-0 .
- Klaus Offenberg: The Millennium Meeting: A Tree Fairy Tale. Agenda Verlag, 2011, ISBN 3-89688-437-9 .
Information about different tree species:
- Tree list
- Federal Office for Forests Austria
- Trees - for children and young people
- 680 Tree Fact Sheets , University of Florida (English)
- GlobalTreeSearch , Botanic Gardens Conservation International (BGCI) (English)
Information about rare Central European tree species:
- to this: Andreas Gruhn: Bureaucrats-German: What is actually a large green in Rheinische Post from July 26, 2007 online
- The dictionary of origin (= Der Duden in twelve volumes . Volume 7 ). Reprint of the 2nd edition. Dudenverlag, Mannheim 1997 ( p. 67 ). See also Friedrich Kluge : Etymological dictionary of the German language . 7th edition. Trübner, Strasbourg 1910 ( p. 42 ).
- Oldest living tree is 9550 years old. In: scienceticker.info. April 16, 2008, accessed February 1, 2017 .
- Simon Egli, Ivano Brunner: Mycorrhiza - a fascinating community in the forest. In: waldwissen.net. October 25, 2011, accessed March 8, 2019 .
- Marcel GA van der Heijden: Underground networking . In: Science . tape 352 , no. 6283 , April 15, 2016, ISSN 0036-8075 , p. 290–291 , doi : 10.1126 / science.aaf4694 , PMID 27081054 ( sciencemag.org [accessed March 8, 2019]).
- Ed Yong: Trees Have Their Own Internet. April 14, 2016, Retrieved March 8, 2019 (American English).
- Peter Wohlleben: How trees send out news bulletins. September 6, 2016, accessed March 13, 2019 .
- Sample , first from Aloys Bernatzky (1966): Climate impacts of green spaces and their relationship to urban planning. Anthos, Journal of Landscape Architecture 5 (1): 29-34. since then reproduced many times
- Burkhard Büdel: Plant ecology I - flora and vegetation history . Lecture notes TU Kaiserslautern.
- Nadja Podbregar: World map reveals tree species diversity. In: Wissenschaft.de . February 22, 2019, accessed February 23, 2019 .
- Tree of the Year - Dr. Silvius Wodarz Foundation. Online at Baum-des- Jahres.de, accessed on February 1, 2017.
- Tree of the Millennium - Ginkgo biloba. Online at Baum-des- Jahres.de, accessed on February 1, 2017.
- Claudia Füßler: City Freiburg, Mooswald, Sternwald. The master of the dream of all foresters. From Freiburg-Dreisamtal.de, accessed on January 21, 2017.
- Claudia Füßler: The master of the dream of all foresters. In: The time. November 24, 2011, online at Zeit.de, accessed on January 21, 2017.
- Now it's official: Germany's tallest tree is in Freiburg. August 18, 2008, online at Baden-Wuerttemberg.de, accessed on January 21, 2017.
- Strasburger: Textbook of Botany. Spektrum, Heidelberg 2008, ISBN 3-8274-1455-5 , p. 423.
- Quaking Aspen ( Memento from February 1, 2017 in the Internet Archive )
- Chau Tu: Earth's biggest living thing might be a tree with thousands of clones. In: PRI Science Friday. May 5, 2015, accessed May 1, 2017 .
- Methuselah spruce: The oldest tree in the world is in Sweden ( Memento from April 20, 2008 in the Internet Archive )
- Karin Wikman: World's oldest living tree discovered in Sweden. (No longer available online.) In: Umeå University. April 16, 2008, archived from the original on April 20, 2008 ; accessed on January 21, 2017 .
- Swedes find 'world's oldest tree'. In: BBC. April 17, 2008, accessed May 1, 2017 .