Environmental factors have a major impact on all living organisms. All living things are constantly under the influence of both organic and inorganic components of the surrounding nature. Each habitat is distinguished by its own parameters - state of aggregation, density, and the presence of oxygen. What environmental factor is called edaphic?
Definition
Edaphic factors include soil conditions in which a plant grows. This is the presence and amount of water, gas, soil temperature. This also includes the chemical composition of the soil. The edaphic factors include the totality of the physical and chemical properties of the soil cover.
These factors are less important than climatic ones. However, they are important in the life of those organisms whose vital activity is directly related to the soil. Other properties that affect the life of various organisms are the physical structure of the soil (friability or density), slope, granulometry. Also, the specifics of species and the movement of animals are influenced by the relief of the soil, soil features.
Edaphic factor for plants andanimals
Soil properties are important not only for plants and microorganisms living inside them. Even at the most insignificant depth underground darkness reigns. This property is critical for animal species that seek to avoid direct sunlight.
As the depth increases, temperature fluctuations in the soil become less critical. Diurnal changes fade quite quickly, and with even greater depth, seasonal temperature changes also lose their significance. At a considerable depth, habitat conditions become as close as possible to anaerobic. Anaerobic bacteria live there. Earthworms also prefer living conditions where the carbon dioxide content is higher than on the surface.
Vegetation and soils
Some types of ions contained in the soil are also of great importance. In this case, the edaphic factor completely characterizes the type of vegetation on the surface, determining which species will grow and which will not take root in given conditions. For example, those soils that are located on limestone layers are very rich in the CA2+ ion. They develop well specific types of vegetation, which is called calcephytic (edelweiss, as well as some varieties of orchids). There are also types of plants that are called calcephobic. These are chestnut, heather, some types of fern.
Also, some types of soil are rich in sodium ions (Na+) and chlorine (Cl-). Such regions are covered with unusual plant species,which stretch in the form of a ribbon along the entire sea coast - Salsola (hodgepodge), Salicornia (s altwort), aster tripolium (tripolium). Ecologists know that the seeds of these plants, called halophytes, can only grow in soil types that are rich in s alts.
Soil composition
Chemical composition is one of the most important edaphic factors. The presence of certain chemical elements, as well as their quantity, is always a reflection of the geospheres that influenced the formation of the soil. In any soil there are those substances that are common in the lithosphere, atmosphere, hydrosphere.
In the composition of any soil in one quantity or another, you can always find almost all the elements of the periodic table of Mendeleev. But the vast majority of them are still found in the soil in negligible quantities. In practice, ecologists who study this edaphic factor deal with only a few at best - usually sodium, potassium, magnesium, manganese, aluminum, etc.
Also, soils contain substances formed during the decomposition of living organisms. The greater the depth, the smaller the amount of such substances. For example, in a forest, fallen leaves are an important source of certain substances entering the soil. At the same time, it is the deciduous litter in the forest that is richer compared to coniferous. It is used as food by the so-called destructor organisms - saprophyte plants, as well as saprophage animals. Saprophytes are usually fungi and bacteria, but sometimes there are alsoplants - for example, some types of orchids.
Oxygen and carbon dioxide
Many experiments have confirmed the fact that plant roots need oxygen in the soil. Their normal development is possible only in the presence of air. If there is not enough oxygen in the soil, then the plants begin to grow more slowly, and sometimes even die. This edaphic factor is also important for the existence of soil microorganisms. Their vital activity occurs only if there is oxygen in the soil. Otherwise, anaerobic conditions develop in the environment, which lead to acidification of the soil.
Thus, plants and microorganisms can suffer from both the presence of harmful chemical compounds in the soil and the lack of oxygen in it. According to its composition, the air that the roots of plants feed on is poor in oxygen and rich in carbon dioxide. It also contains water vapor, and in some areas - for example, in marshy soils - gases such as ammonia, hydrogen sulfide, methane, and hydrogen phosphide are also present. They are formed as a result of anaerobic processes that accompany the decomposition of dead organic tissues.
Water
An equally important edaphic factor is the water content in the soil. First of all, it is important for plants. S alt compounds dissolve with water and become more available to plants. Most types of plants are negatively affected by drought, when the surface dries out. This edaphic environmental factor is no less important formicroorganisms, the vital activity of which occurs only with a sufficient amount of moisture.
With the naked eye, you can see how different the vegetation is on dry soils and those that are rich in water. The fauna is also sensitive to this factor - animals, as a rule, do not tolerate too dry soil. For example, earthworms and termites sometimes supply their colonies by burrowing deep galleries underground. On the other hand, if there is too much water, the larvae die in large numbers.
