Biotic bonds in nature. Examples, types of biotic bonds

Biotic factors of nature are relationshipsall living organisms with each other and with the environment. Biotic bonds arise in the biogeocoenosis between different species. The most basic and important form of such connections is food relations, which form food cycles and complex chains.

Neutralism

Biotic relationships in which life activityone organism has no effect on the life of another, is called neutralism. Examples of this relationship are hare and ribbon worm, butterfly-urticaria and flea, as well as an infinite number of others.

Scientists have noticed that during theirvital activity, all living organisms release into the environment solid, liquid and gaseous substances that can affect other plants, animals and microorganisms.

Allelopathy

Biotic bonds, which are due to specific active metabolic products released into the environment, are called allelopathy.

This phenomenon is known for a long time, but only in 1937 the German scientist Molish gave him a certain name.

In more detail this phenomenon has been studied inplant organisms. Isolation of many plants can exert both toxic and stimulating effects on the neighboring neighbors. Examples of biotic bonds in plants can be:

• absintine leaves of bitter wormwood can inhibit the growth and development of many other plants;
• beans slows the growth of spring wheat;
• allocation of roots of wheatgrass badly affect not only other herbs and shrubs, but also trees.

Animals also release substances - pheromones, capable of influencing the behavior and development of individuals of a particular species. With their help, information is also transmitted to other species.

The isolation of biologically active substances is also characteristic of microorganisms. For example, antibiotics such as penicillin and streptomycin are widely known.

Effect group

The group effect is the optimization of allprocesses, which leads to the maximum increase in the viability of individuals in their cohabitation. This feature is manifested in a large number of species that can normally reproduce and develop only if they have merged into small or large groups.

The types of biotic connections depend on the habitat of individuals and the ways in which they exist. For example, in order to survive a herd of African elephants, it must be at least thirty individuals.

Competition

Biotic bonds, during which occurthe relationship between individuals of one or the different species, under which the same resources are used for their significant deficiency, are called competition. Intraspecific competition can significantly increase the intensity of natural selection. The most popular example of this process is the self-thinning of spruce.

But the interspecific type of competition is most oftenis characteristic for ecologically close individuals or populations of different species. Can be both passive and active. The first implies the use of natural resources needed by both species. And during the second there is a suppression of one species by another.

The competition is one of the main reasonsthe fact that several species, characterized by a similar way of life, behavior and specific food, can not cohabit in one community. Such competition can turn into enmity.

Predation

Biotic bonds in nature, whichcharacterized by such a method of food production, as catching, killing and eating the caught individuals, are called predation. The basis of such relationships are food links and food chains. Predator first kills prey, but only then it eats. But before that, you need to catch it. For these purposes, each predator has special adaptations. Historically, the victims have protective elements. For example, carapace, spines, thorns, poisonous glands and protective paint.

Thanks to such mutual adaptations, groups of organisms - predators and prey - were formed. In such relationships, the principles of regulating the size of both components are formed.

Until recently, scientists thought that all predators -harmful inhabitants of the planet, so they need to be exterminated. However, this opinion was erroneous. Such actions will have negative global consequences. There is a risk of damaging not only the wild nature, but the whole economy.

Symbiosis

Biotic bonds in nature, during which one of the partners (or both at once) benefits from relationships with each other, are called symbiosis.

There are a lot of examples in the worldmutually beneficial symbiosis. For example, gastric and intestinal bacteria, without which the digestive process is impossible. Or pollination of some orchids, whose pollen can tolerate only a certain type of insect. Such relationships are successful when they increase the likelihood of both partners to survive.

In other words, it is absolutely any form of relationship between organisms of different species (this includes parasitism - a special kind of relationship that is beneficial to one partner, but harmful to another).

Symbiosis, which will be beneficial for bothrepresentatives, is called mutualism. But commensalism is a relationship that is useful to one, but indifferent to another. Endosymbiosis is the ability of one partner to live within the cell of another.

Mutualism

The most common form of jointcohabitation is considered mutualism. Biotic links in nature (the 9th grade of the school curriculum describes this topic in detail) in the form of mutualism are a prerequisite - the existence of both partners. During this communication, each of the partners receives their benefits. For example, one partner uses the other as a power source, and the other is protected from enemies or under favorable conditions for development and reproduction.

Every participant in a mutualistic couple is selfish, and mutual benefit only arises from the fact that the benefits obtained outweigh all the costs that are required to maintain a relationship.

Mutually beneficial ties are also formed thanks tobehavioral reactions. Examples of biotic links mutualism - birds combine their own food, and at the same time are seed spreaders. Sometimes physical relationships arise.

The close contact of species under mutualism contributes to their joint evolution. Such an example are the devices that have formed in flowers and their pollinators.

Commensalism

Biotic relations (grade 9) distinguish three types of commensalism:

1. Use food of other species.
2. Attached to another organism, which becomes the "owner".
3. Settled in the internal organs of the host.

This type of relationship is very important to nature,as they provide an opportunity to cohabit a large number of species on each piece of the Earth, as well as to maximally master the environment and use food resources.

However, very often this type of communication goes intoother relationships. When eating food begins to harm the owner, the relationship moves to a new level and becomes parasitism or competition.

Parasitism

Parasitism is the kind of relationship in whichthe parasite uses the host as the main residence and source of food. Biotic connections (the table is presented in the article) describe this type of coexistence of individuals as follows: the parasite settles inside the host or on its surface. Parasitism can occur among various groups of organisms (in plants, animals, fungi, and humans).

The physiology of the parasite is subject to lifehost processes. Therefore, for productive existence, it is necessary to use biological resources. The longer the coexistence takes place, the better this type of parasite adapts to its owner and causes him less harm.