Deciduous tree - Mode of operation
A tree is a perennial plant, which consists of a root, stem, branches, twigs and leaves. At our latitude, the deciduous tree sheds its leaves in autumn, so that it does not become parched in the winter. The upright growth habit is contingent to the dominance of the top bud of the final bud, also called the terminal bud. The growth substances formed in this bud, called auxins, prevent the growth of side shoots and thus growth by width. In some species of deciduous trees, this phenomenon subsides over time and the deciduous tree crown forms. Deciduous trees belong to the flowering plant group (angiosperms). Although there are more types of deciduous trees, conifers (gymnosperms) are more commonly found. Deciduous trees belong to the flowering plant group (angiosperms). Although there are more types of deciduous trees, conifers (gymnosperms) are more commonly found. (Repetition in source text.)
The tree and its roots are supplied with water and nutrients. With regard to root formation, there are big differences between the various species of deciduous trees. We differentiate between tap-rooted plants, heart-rooted plants and shallow-rooted plants. The heart root is very frequently represented in deciduous trees. The entire root mass of a tree corresponds to up to 25% of the mass of the other parts of the tree.
The trunk of the tree consists mainly of wood (xylem). Firstly, it has a static function. It connects the roots to the crown and serves as the medium with which the tree grows in height; this is important for the competition for sunlight in the forest. Secondly, the stem and crown are supplied with water and nutrients and then vice versa to the roots with assimilates which form in the leaves. The water rises to the crown in the phloem just behind the bark in the sapwood inside the trunk, and then flows downward. The rising water can reach a speed of up to 50 meters per hour. Crown The crown of the deciduous tree is formed out of twigs and branches. It is the tree's habitat above ground and seeks to absorb as much light (sunlight) through the leaves as possible. There are two types of crowns. The shade crown (e.g. maple, beech, hornbeam) is not leafy inside as opposed to the light crown (such as birch, oak, alder).
The appearance of leaves in terms of shape, colour and size is the main distinguishing feature of trees. Alternatively, the type of tree can be determined on the basis of the buds, flowers, fruit and the habitus. The most important function of a tree apart from the binding of dust particles and the provision of shade is photosynthesis.
There is a green dye in the leaves of trees, called chlorophyll. The chlorophyll is needed to ensure that the leaves can produce nutrients from water and carbon dioxide. The water comes from the root and the carbon dioxide comes from the air. The process takes place in the chlorophyll cells of the leaves, i.e. the chloroplasts. The air is absorbed from the bottom of the leaf, which fills the spaces between the cells. In sunlight, chlorophyll is induced and takes in carbon dioxide from the air. This clogs itself with water to form a chemical reaction which results in the formation of glucose. The glucose gives the tree energy which it uses to live and which can be transported to any part of the tree.