Part 10
The role of the soil layer in forest life is great and diverse. It is most noticeable in relation to green forest dwellers. The properties of this layer primarily determine the type of forest, many features of forest phytocenosis. Where the soil is sandy, nutrient-poor and dry, pine forests usually develop. Clayey soils contain more nutrients and moisture, which results in the development of completely different forest types under these conditions.
The roots of forest plants, penetrating the soil, take water and necessary nutrients from there. The main mass of roots is concentrated in the upper layer of the soil, i.e. in the soil itself. The soil near its surface is the most saturated with roots, as it is here that the most nutrients are found. The number of roots decreases sharply with the depth of the soil.
Soil-ground layer is important not only as a source of water and mineral nutrients for green plants, but also as a source of decomposition products of dead plant residues, which are absorbed by the soil. Consequently, the soil layer not only gives away, but also receives. There is a continuous exchange of substances between this layer and the plants.
Soil is also of great importance in the life of forest fungi, soil microorganisms and many representatives of forest fauna. This layer is necessary for the life of earthworms, mouse-like rodents, moles, numerous insects, etc. Various mammals, such as foxes, badgers, etc., are dug out in the soil layer.
A very important role in the life of the forest is played by litter - a layer of fallen leaves or needles, which covers the surface of mineral soil. Litter is one of the most characteristic features of the forest, its essential part. It is well developed in many types of forests. Many of the processes taking place in the forest are somehow connected with litter. It affects the life of plants and small animals, the water regime and the nutrient properties of the soil.
The composition of litter in different types of forests varies greatly. This depends primarily on which trees form the forest - conifers, deciduous or both. The litter of all types of forest includes not only leaves and needles, but also thin dead tree branches, bark pieces, remains of plants growing on the
soil, etc.
The capacity of litter also varies greatly in different types of forests. This is best seen in summer. In linden forests, for example, there is almost no litter at the end of summer. The reason for this is that linden leaves decompose very quickly on the ground. During the time that passes after the autumn foliage, the leaves have time to decompose almost completely.
We can see a completely different picture in summer in many of our northern spruce stands. Here the bedding layer is very powerful - sometimes it reaches 10 cm thick. It also has its reasons. Fallen pine needles are slowly decomposing by nature. Especially its decomposition slows down at low temperature and high humidity. These are the conditions in the northern spruce woods.
Formally, the litter belongs to the soil, is the uppermost soil horizon. But in fact, it is a very special formation, which is like a link between living green plants and the mineral soil.
The importance of litter in the life of the forest is that it is a kind of piggy bank of nutrients for green plants. Leaves and needles that fall off trees contain a known amount of nitrogen, phosphorus, potassium, calcium and other elements necessary for the life of green forest dwellers. Leaves bring these nutrients with them when they fall to the ground. The bedding is relatively rich in plant nutrients, and there are incomparably more of them here than in the mineral horizons below. However, nutrients are in a tied condition, they are part of complex organic compounds and are almost inaccessible to green plants. In the process of decomposition of decay, the nutrients become available and they reach the roots. Decomposition of the litter is relatively slow and the nutrients are released gradually, in small quantities. This allows plants to make the most of their nutrients.
The litter in the forest serves as a layer in which many thin suction roots of various forest plants are concentrated. The root system of some forest herbs is almost entirely in the bedding: acidity, buttercupus, etc. Such plants are called root litter plants. In some types of forests, litter serves as a place of concentration of tree roots (e.g., when permafrost is close to the ground). In this case, it becomes particularly important in the life of the forest.
The role of litter in the forest is diverse, for example, the litter layer prevents the germination of fallen seeds of pine, spruce and some other trees with fine seeds. Where the soil is covered with bedding, there is very little growth of trees. But if this obstacle does not exist, the teenager appears in a large number of cases.
The continuation should be...