Ecological groups of plants: characteristics, examples
Living organisms interact with their environment. In order to withstand adverse conditions and apply them with maximum benefit, they develop certain morphological, anatomical, physiological and reproductive functions. A collection of species with similar characteristics and environmental requirements forto anyfactor is called an environmental group. Ecological groups of plants are distinguished in relation to light, water, and soil.
What is the adaptation of organisms
Any feature of the organism or its part, which allows it to exist in its own habitat conditions, is called adaptation. Each individual develops in a certain adaptation, as well as in the community. The completion of a life cycle is the result of a number of adaptations that are important for survival.
Classification of plants in relation to the soil
Mechanisms for adaptation include functions such as preventing the destruction of vital vegetative tissues, production assistance and the effective distribution of reproductive organs. Ecological groups of plants and animals are divided into hydrobionts (capable of swimming or living in water), terrestrial and soil organisms.
The Danish scientist, botanist and microbiologist Johannes Eugenius Warming in 1895 for the first time determined the influence of controlling or limiting factors on the flora. He identified several ecological groups of plants in relation to water and based on the nature of the substrate in which they grow.
Warming has systematized plants based on a natural substrate (soil) into the following groups:
- plants of acidic soil (oxylophyte);
- plants of saline soils (halophytes);
- growing on sand (psamofity);
- growing on the surface of rocks (lithophytes);
- growing in the crevices of rocks (Hazmofity).
Epiphytes are not included in the above systematization due to the fact that they do not have a permanent connection with the land.
Classification of plants in relation to moisture
The second classification of Johannes Warming, established in 1909, is based on the relation of the ecological group of plants to water.
Organisms are divided according to the need for moisture and soil as follows:
- Hydrophytes - growing near the water.
- Xerophytes - adapted to survive in conditions of a small amount of moisture in habitats.
- Mesophytes - growing in an environment that is neither very dry nor very wet.
What ecological groups of plants are isolated from drought-resistant organisms? Xerophilous individuals are additionally classified based on their habitats:
- oxylophytes (grow on acidic soils);
- halophytes (on saline soils);
- litofity (on the rocks);
- psammofity (on sand and gravel);
- hersophytes (in wastelands);
- Eremophytes (in steppes);
- psychrophytes (on cold soils);
- psilophytes (in the savannah);
- sclerophitis (trees and shrubs).
Features of hydrophytes
Hydrophytes (from the Greek. Hudor - water and Phyton - plants) - an ecological group of plants that grow in wet places or in water. The stems and leaves of such individuals may be partially or completely submerged in water. Examples of aquatic organisms: pemphigus, valisneria, lotus, water hyacinth, duckweed.
The peculiarity of adaptation in the aquatic environment is that the conditions of this environment change regularly. Plants have to grow with a minimum of nutrients in a dissolved state. With increasing depth of water bodies, light and oxygen becomes less and less.Zonality of aquatic vegetation with increasing depth is a device for maximum utilization of light energy.
In the aquatic environment, there is constant movement, starting with a small vertical circulation, ending with a strong current. Since moisture makes up most of the body of plants and animals (from 70 to 90% of water in protoplasm), it affects all life processes directly. For hydrophytes, the rate and extent of photosynthesis, respiration, absorption of nutrients, growth and other metabolic processes depend on the amount of available water. Low relative humidity of air increases moisture loss due to transpiration and affects the growth of organisms. Conversely, individuals in regions with high humidity show a decrease in transpiration.
Some aquatic groups of higher plants probably originated from mesophytes. In the course of evolution, changes in physiology, morphology, and behavior related to aquatic lifestyle have influenced the mesophytic individuals to adapt to life in a moist environment.
Features of xerophytes
Xerophytes are an ecological group of plants that grow in dry habitats.
Drought-resistant areas can be of the following types:
- Physically dry, where the moisture holding capacity of the soil is very low, and the climate is dry.
- Physiologically dry, where water is present in excess, but can not be absorbed by plants. Such places may be too salty, sour, hot or cold.
- Habitats are dry both physically and physiologically.
Xerophytes are characterized by growth in desert and semi-desert areas, but they can grow in places where water is available in sufficient quantity. These organisms withstand extreme dry conditions, low humidity and high temperatures.
When growing in a favorable environment, plants develop special structural and physiological features that are mainly aimed at the following goals:
- to absorb as much water as they can get from the environment;
- to retain moisture in their bodies for a very long time;
- to reduce the coefficient of transpiration dominium.
Xerophytes are divided into several ecological groups of plants,depending on the degree of resistance to dry conditions:
- Refugioxerophytes or drought-avoiding organisms are short-lived xerophytes. In critical periods, they survive in the form of seeds and fruits that have a hard and stable outer layer. With the emergence of favorable conditions, the seeds germinate in new plants of small size, completing the life cycle in a few weeks. Such individuals remain unchanged in extreme conditions. They are common in the semi-desert zone, where the rainy season does not last long.
- Sclerophic plants are small plants that can tolerate or tolerate a lack of moisture and flow into anabiosis.
- Drought-resistant individuals can withstand extreme drought.
Xerophytes grow on various biotopes. Some - on stony soils and in deserts, on sand and gravel.
Features of mesophytes
Mesophytes are an ecological group of land plants whose habitats are neither excessively wet nor too dry. These plants are not able to be in water or on marshy soils and cannot survive in dry places. In other words, mesophytes are organisms that grow in those regions where climate and soil are favorable. The flora of forests, meadows and cultivated fields belongs to this category.
Environmental groupsplant mesophytescan be classified into two main categories:
- trees and shrubs.
The first category includes annual or perennial grasses. Tothe second are representatives of forests.
Classification of woody plants
A group of woody plants inturn divided bythe following classes: mesophytes, deciduous forests andtropophytes. Mesophilic spaces, covered with shrubs,arise where temperature andother conditions are notare favorable for forest development. Inmany places are xerophytic andmesophytic spaces merge with eacha friend.
Deciduous forestsare situated inareas where precipitation is quite high (about 75year) anduniform as welltemperature is average. Such places characterize trees that get rid offoliage incertain periods of the year. Leaves are saved infor about 5months. This phenomenon is characteristic of moderate andcold regions. Most plants are pollinated by the wind. The soil is very rich in microflora. Deciduous forests are named inhonor of the dominant trees of these specific communities: oak forest, birch forest.
Features of tropophytes
Tropophytesinteresting group of tropical organisms that can be included inmesophyte group. As a rule,tropical regions, the climate remains more or less uniform infor a year butIn some regions, there is an alternation of wet anddry season. Plants growing insimilar conditions, developed structural changes, thanks to which they learned to withstand a regular cycle of favorable andadverse seasons. Tropofit able to behave like a mesophyte inrainy season andlike xerophyte indry season. Scattering of leaves can occur inearly winter or summer.