How water rises in trees

On the biology of trees



White beech (shrubby), red beech (deciduous tree), silver fir (conifer)


Trees are the largest living things on planet earth. A tree has a lignified one tribewhile getting a shrub already branched at the base and several lignified Trunk trains. The top part of a tree is called Crown, the Branches are long shoots that grow from the terminal buds or short shoots that arise from the lateral buds and which leaves wear. Species like white beech or hazel can grow as a shrub or as a tree. The Conifers (also Conifers, conifers) represent a large order within the naked-seed plants. In these, the ovules sit open on the carpels. The male flowers develop stamens with pollen sacs that release the pollen to pollinate the female flowers. Develop conifers Conesas seed heads from the female inflorescences, one correctly speaks here not of a fruit. The leaves, the needles, are long and narrow in the conifers, the flowers rather inconspicuous. The Deciduous trees do not include an order within the system of seed plants, but rather all trees in the section of flowering plants. In the case of deciduous trees, the trunk branches as a rule from a certain height, in the case of conifers the straight trunk usually does not divide up to the top.


 


The lignified one tribe in trees forms from the shoot. The trunk gives the tree its strength and transports water and nutrients. If you saw up a tree trunk, different zones can be identified. The outermost layer is known as bark. The bark is the outer part of the bark, it protects the tree from the elements. As it grows, it tears open and gives the bark its typical appearance. This is particularly beautiful to see with the silver birch. The bast consists of a fibrous tissue in which the nutrients are transported from the leaves to the other tree organs. In the very thin one under the bark Cambium new cells are formed. From there the growth of a trunk starts. That forms inwardly Sapwood, in which water and nutrients are transported from the roots to the leaves. Inside is the hard part Heartwood, which consists of dead cells and is filled with impregnating substances such as tannins or resins and fats. The softer one mark forms the innermost part of the heartwood. From the pith, the pith rays branch out through the heartwood, within which nutrients and water can be transported horizontally in the trunk.
  
If the tree is supplied with many nutrients for leaf formation in spring, large cells tend to form and the young wood appears rather light. Nutrients are stored in autumn and winter. In the process, rather small, thick-walled cells form, the new wood then appears rather dark, a narrow ring is created. The resulting Annual rings give an insight into the entire life of a tree. If the bark is injured or in young wood, the tree is secreted as a protective measure to close wounds resin from. Turpentine oil can be extracted from this viscous and sticky liquid. This is used as a binder for paints or as a cleaning agent.
 
The transport of water and nutrient salts from the roots to the top of the tree at heights of up to 100 meters is a masterpiece of the trees. The transport tubes in the sapwood are so thin that one Capillary action arises. The phenomenon can be observed in a model experiment: if you hold a thin glass tube in water, the liquid rises a little in the narrow glass tube due to the surface tension of the water. But there is also a second reason for the water transport to great heights: When water is released from the leaves, a gap is created between the root and the leaf Water potential, to balance the pressure, the water is drawn from the roots.
 
Photosynthesis and cell respiration take place in the green leaves. The necessary Chloroplasts in the cells contain the green leaf pigment Chlorophyll. If the incidence of light is low, a tree needs more oxygen than it can produce itself. He then takes in oxygen from the environment. In a large tree like the European beech there are sun and shade leaves. The Shadow leaves can gain energy for their own needs and produce oxygen even with very little light. The Sun leaves on the other hand, they are able to produce as much carbohydrates and oxygen as possible in a lot of light In autumn, deciduous trees such as the maple produce xanthophylls in order to ensure energy generation with reduced radiation. Because of this, the leaves on the deciduous trees turn yellow in autumn. If the dying leaves can no longer process the oxygen, the yellow pigments oxidize and the leaves turn red.Evergreen trees do not shed their leaves in winter, but they regularly - especially in spring and summer - replicate new leaves as soon as some have been shed. Some conifer species such as the silver fir, the spruce or the pine belong to it, while the larch sheds its needles in late autumn and the deciduous trees is assigned.
 
The roots can be seen as a continuation of the trunk into the ground. They absorb water and nutrients and solidify the soil. A large deciduous tree can transport up to 500 liters of water up the trunk per day. Trees like oak, red fir or pine have deep depths Taproots that grow vertically into the ground. Smaller lateral roots form from them, which branch off obliquely or horizontally. The roots are fine with Root hairs Mistake. Most tree species enter into a symbiosis with fungi in their root system. The fungi grow together with the root bark, they take over the function of the root hairs and enable an exchange of nutrients with the plant. The fungus helps the tree with the supply of nutrients and water, in return it gets the carbohydrates produced by the tree through photosynthesis. The nodule bacteria, which are also linked to the root system, convert atmospheric nitrogen into nitrogenous nutrient salts and thus help the tree to get inorganic nutrients, for which they receive organic nutrients from the tree.
 

 

At mono-ewned trees come from one Tree male and female flowersCut in front. These include oak, red beech, white beech, silver birch, spruce and pine. In willow and poplar, the male and female flowers only appear different Trees, this is dioecious trees. At hermaphrodite flowers Male and female sexual organs are simultaneously developed differently on one flower, for example in the horse chestnut or in certain types of maple such as the field maple. The flowers of the covered trees are showy and need pollination to reproduce. The most common are those Wind pollination and the Insect pollination. When the fruit is formed, the tree must ensure that the seed is carried far away so that a newly growing tree does not compete with the old tree. The trees have developed ingenious strategies for this. The winged split fruit of the maple enables propeller flight. The seeds of the chestnut are very large, they roll away from the tree. It is often accepted that the seeds are collected and eaten. Squirrels can often no longer find acorns and hazelnuts in their winter hiding place, so they germinate in spring. Other seeds are so hard that they can be eaten but the seeds they contain cannot be digested.