Vegetation of even a small plot of land is unusually diverse. And you can observe how very different the plants of the forest are from those that live in a meadow or a lake. Representatives of the flora can only coexist with those species with which they are ready to coexist. That is, plant life is possible when a certain plant community has developed.
Basic concepts
To understand what a plant community is, one must remember the requirements of various plant species for growth and development conditions. Each of them needs a certain humidity, lighting, temperature conditions. Based on this, in nature, individual plant species do not live in isolation from each other, but together, forming thickets called phytocenoses or plant communities.
So, a plant community is a collection of plants that have adapted to the same conditions of existence on a given piece of land and are connected by mutual influence on each other.friend.
The more diverse the species composition of the phytocenosis, the more fully the living space and its resources are used, the richer and more diverse the interconnections become. For example, the forest provides food and shelter for many different animals, and they provide its stability by destroying pests, spreading seeds, and loosening the soil.
All types of plant communities living in a certain area are called vegetation. Depending on the predominance of certain species, phytocenoses are combined into large groups (vegetation types). Each of the groups got its own name, for example, meadow, forest, swamp, steppe, tundra, and so on. All types of vegetation have their own characteristic features, which make it easy to distinguish them from each other.
Types of plant communities
As already mentioned, phytocenosis is characterized by a certain type of soil, level of illumination, humidity and other conditions for the existence of plants. This explains the diversity of plant communities and the specific composition of the flora for each of them.
When they say that a plant community is a forest, a field, a meadow, a reservoir, a virgin steppe, etc., then it is precisely the conditions for the existence of species that are meant.
Sometimes the name of a phytocenosis is given according to the dominant species in it. For example, spruce forest, pine forest, birch forest, oak forest or feather grass steppe. Communities within the same type may differ in species composition, for example, there are sorrel spruce forests or blueberries.
Classify and identify types of plant communitiespossible, given the influence of man on the process of formation of phytocenoses. Based on this, natural and artificial plant communities stand out.
All representatives of the flora of forests, meadows, swamps, lakes, steppes, tundra constitute natural plant communities. A person did not have a direct impact on their formation.
Artificial phytocenoses are created by man. They can be formed in the likeness of natural ones (for example, a forest, a pond, a meadow) or have no analogues in nature (a field, a square, a park). Due to the small species diversity, such plant communities are weaker than natural ones and can exist only when a person takes care of them.
Otherwise, plant communities change. Representatives of the flora of the field can be displaced by the plants of the forest. A similar process is also possible in natural communities. So, the lake, slowly overgrowing, turns into a swamp.
It must be remembered that different types of plant communities attract certain types of animals, bacteria and fungi. Together they form a biocenosis.
Meadows and steppes
Herbaceous and small shrub plants predominate in the steppe. The meadows are characterized by a wide variety of herbs, mostly perennials. The floodplain meadows located in the floodplains of the rivers have the richest composition of species. As well as upland meadows, located far from rivers, in elevated places.
Forest
Multi-tiered plant community, the most complex species composition is the forest. It includes woody, shrubby and herbaceousplants. Forests are divided into deciduous and coniferous. Those, in turn, are divided into broad-leaved, small-leaved, dark coniferous and light coniferous. In addition, there are mixed forests, where both coniferous and deciduous trees are represented.
Walking through the forest, we enter into the possession of a community. A good connoisseur of nature, an experienced picker of mushrooms and berries will go for lingonberries to the thicket of a coniferous forest, for a bouquet of flowers - to clearings and glades, and for strawberries - to sunny hillocks and edges. How do different plants get along? What makes their existence together possible?
A plant community consists of many plant species adapted to the same natural environment but using it in different ways. After all, the requirements for light, moisture, temperature conditions are not the same for them.
For example, how do forest plants use light? Light-loving oaks, ash-trees, lindens carried their crowns to the uppermost tiers. In the second tier, mountain ash, bird cherry, aspen feel comfortable. These trees are less demanding on light. Shrubs are located in the third tier. And the most shade-tolerant, mosses and grasses, are located in the fourth.
The forest plant community has a unique component called the forest floor. Sometimes scientists rank it in the fifth tier. Mushrooms are the main inhabitants of the litter. Together with fungi, small forest inhabitants and bacteria have adapted to the existence in it. Feeding on dead parts of plants, they turn them into humus, and humus– into mineral s alts, which are vital for new plants.
Laying also exists underground. Tree roots are deep. Shrubs took root a little higher, and herbaceous plants near the surface. The tiered arrangement of the roots allows them to absorb nutrients from different soil layers.
Seasonal principle of existence
Getting along with each other in the forest allows not only the tiered placement of aboveground and underground parts of plants, but also their development at different times.
First, before the leaves bloom, wind-pollinated ones bloom. While the tall trees have not yet blossomed, the wind will freely carry the pollen.
The snow hasn't even melted yet, and insects have already awakened on the warm forest floor below. Now, when the bare branches of the forest let a lot of sunlight down, insect-pollinated primroses are blooming.
Shrubs have turned green, and primroses have had time to fade, accumulate nutrients in rhizomes. Their life fades away until next spring. And other herbs take their place. As long as there is a lot of light in the forest, the grass cover becomes thicker, more diverse, and the process of photosynthesis is actively going on.
Under the blossoming green tent, when it gets warmer and the wind subsides, insect-pollinated plants of the undergrowth will bloom. Thus, the conditions necessary for the life of all its representatives are consistently created in the forest.
Spruce forests
Spruce forests usually grow on heavy loamy soils. Spruce needles, falling off, decompose slowly. Accumulating over the years, it forms a litter,which affects the humidity, temperature regime of the soil and some of its other characteristics. There is little light in the spruce forest, the humidity is high. Even on a hot summer day it is cool here. The grass cover is not rich in species. Shade-loving oxalis, various types of mosses, blueberries, lingonberries grow under dense fir trees.
Pine forests
Forests where the main representative is pine are called pine forests. They prefer light sandy soils. There is enough sunlight in them, but due to the lack of nutrients, the diversity of plants is small. The soil here is covered with mosses and lichens. Bone, blueberries, lingonberries, and some types of ferns grow among them.
Broad-leaved forests
The plant community of broadleaf forests is generally associated with soils rich in minerals. The species composition here is varied. Of the trees you can find oak, linden, elm, maple. Of the shrubs, hazel, forest honeysuckle and euonymus most often come across. The herbaceous cover is rich in species: hoof, raven eye, gout, several varieties of bluebell, anemone and many others.
Swamp
This plant community is represented by unique species that can exist in conditions of excessive soil moisture and lack of oxygen in it. In Russia, swamps are most widespread in the north of the forest zone and in the forest-tundra.
They are divided into lowlands, which, in turn, are sedge and moss, and upland. Each of them has a characteristic composition of plant forms.
Lake
The plants of the lake are different, butlive in the same natural environment. Just use it differently.
At the shore, where it is not deep, there are reeds, cattails, reeds. Their stems and leaves are placed above the water. They get carbon dioxide from the air and a lot of light. The egg-pods also grow here. Their stems are rooted at the bottom, and their long petioles carry the leaves to the light.
But there are plants that do not rise to the surface. They take nutrients directly from the water and are content with diffused light. The deeper, the less. The plant composition is also changing: there are few higher plants, mainly microscopic algae.
In nature, every plant community is associated with a community of animals that inhabit the same area. So the coastal thickets sheltered many inhabitants of the lake, since there is enough light, heat, and food resources in shallow water.
The life of the reservoir would be impossible without the activities of its inhabitants. They clean the lake, participate in the cycle of substances, in a word, with their vital activity they maintain the constancy of the habitat. They are interconnected by this environment. The established community creates the conditions necessary for the life of all its members.
Tundra
Tundra plant communities are in special conditions. There is little heat here, frequent strong winds, permafrost.
Tall trees do not grow in harsh conditions, but this does not mean that they do not exist in the tundra, they are just very small, undersized. Onlyhere you can see boletus trees that are taller than a birch. Or a tree along with a cloudberry bush.
Polar trees grow very slowly. Annual rings are distinguishable only with a magnifying glass, their width is calculated in hundredths of a millimeter.
Tundra plants adapt differently. For many, pillow growth is characteristic. This form helps to withstand hurricane winds. The inside of the pillow retains heat better. Mosses and lichens, flowering shrubs, and herbs grow in the tundra.
Human influence on plant communities
The formation of a certain plant community takes more than one millennium. And, once formed, it can persist for a long time until its interconnections are broken.
Failure in the life of even a small area of the forest can not pass without a trace. For example, a corner near a forest river was a favorite place for tourist h alts. The grass cover and young forest growth died from many fires. The shrub that protected the slope from landslides was cut down. Having lost its green protection, the river began to dry up.
Changes in the life of the plant community have led to undesirable changes in the natural environment.
Inhabitants of the tundra are well aware of the laws of nature of their land. So, for example, driving herds of deer from place to place, they preserve vegetation. After all, moss pasture eaten by deer is restored in 15–20 years. The layer of soil that thaws in summer is very thin, the bottom is permafrost and the vegetation cover is thin.
Tundra natureunusually vulnerable. And every abrasion inflicted on the vegetation here takes a long time to heal.
Any activity of people on earth cannot but affect the life of plants. And if a person knows what a plant community is, according to what laws it develops, then he will act carefully and reasonably.
