What is interspecific competition? Examples

Demecology is a scientific discipline that considersthe variety of relationships between living organisms in different populations. One of the forms of such interaction is interspecific competition. In this article, we will consider its features, patterns of the emergence of the struggle for territory, food and other abiotic factors in organisms living in natural and artificial biogeocenoses.

Kind and its ecological characteristic

During the historical development of biologicaltaxa (groups that have a certain generality) adapt to the abiotic and biotic factors of nature. The former include the climate, the chemical composition of the soil, the water and air environment, etc., and to the second - the impact of the vital activity of some species on others.

Individuals of one species settle on certainareas of biotopes are uneven. Their populations are called populations. Communities of one species are constantly in contact with populations of other species. This determines its position in the biogeocoenosis, which is called the ecological niche.

interspecific competition example

Interspecific competition, an example of which weconsider in the article, occurs directly in places overlapping the range of communities of different species and may lead to the extinction of a population of one of them. For example, in the experiments of the Russian scientist G. Gause two species of infusorians developed on the same nutrient medium. One of them began to multiply actively and grow at the expense of another. As a result, the weaker species completely eliminated (died out) within 20 days.

What is the result of overlapping of areas

If the habitats of two different species aresome areas of the biotope merge, then between the individuals there are quite strong differences in the external structure, the timing of puberty and mating. They are called the displacement of signs.

On the periphery of the range, where organisms live onlyone species, their populations are convergent with communities represented by individuals of a different species. It should be noted that in the second case there is practically no interspecific competition between populations. An example with the finches, observed even by Charles Darwin in the Galapagos Islands, during his round-the-world trip on the Beagle frigate, is a vivid confirmation of this.

interspecific competition

The law of competitive exclusion

The above-named scientist G. Gouse formulated an important ecological regularity: if the trophic and other needs of populations of two different species coincide, then such taxa become competing. This excludes their further coexistence in one area, since inter-species competition arises between them. An example, which illustrates it, is the fluctuation in the number of perch, rudd and roach, feeding in one pond. The fry of the roach is more active and voracious, so they successfully supersede the young perch and ruddings.

 interspecific competition examples of animals and plants

Sympatric and allopatric taxa

They arose from the geographicalspeciation. Consider species called allopatric. In order to explain the fact of their appearance, the data in geology and paleogeography are used. Individuals of such communities compete with each other quite strongly, since they require the same feed resources. It is this feature characterized by interspecific competition.

Examples of animals that have undergone geographic speciation are North American beavers and mink. Several hundred thousand years ago, Asia and North America were connected by a land plot.

 interspecific competition

On the mainland aboriginal species of rodents lived. When the Bering Strait appeared, the Eurasian and American populations of these animals, as a result of divergence, formed new species competing with each other. Differences between individuals of populations are amplified as a result of the displacement of traits.

Is it possible to reduce interspecific competition?

Once again, we will clarify that in demecology the interspeciescompetition is a relationship of organisms that are part of a population of different species and require similar resources necessary for their livelihoods. This can be a biotope space, light, moisture and, of course, food.

In natural conditions, communities of differentTaxa, using a common area of ​​range and food supply, can reduce the pressure of competition in various ways. How does interspecific competition decrease? An example is the division of the range, leading to different types of feeding of waterfowl - cormorant large and cormorant long-nosed. Although they live on a common territory, but the individuals of the first species feed on the bottom forms of invertebrates and fish, and the second - they get food in the upper layers of the water.

For autotrophic organisms is also characteristicinterspecific competition. Examples of plants that confirm the mitigation of the struggle for existence are herbaceous species and tree forms. These populations have a multi-leveled root system, which provides separation of subterranean strata, from which plants absorb water and minerals. Plants forming the forest litter (anemia, butterfly, bearberry, bearberry) have a stem root length from a few millimeters to 10 centimeters, and perennial tree species of gymnosperms and flowering plants range from 1.2 m to 3.5 m.

Interference competition

This form occurs if different speciesuse the same environmental factor or resource. Most often this is a common food base. In insects, as in plants and animals, interspecific competition is also widespread.

Examples, photos and description of the experiment,Below, the study of Park R., carried out under laboratory conditions, explains. The scientist used in the experiments two types of insects belonging to the family of darkling beetles - flour masters (flour crustaceans).

interspecific competition examples biology

Individuals of these species joined each other in competition for food (flour) and were predators (ate other types of hruschaks).

In the artificial conditions of the experiment,abiotic factors: temperature and humidity. With them, the probability of dominance of communities of one or the other kind has changed. After a certain interval of time, only one species was found in an artificial environment (a box of flour), and the other completely disappeared.

Operational competition

It arises as a result of a purposefulthe struggle of organisms of different species for the abiotic factor, which is at a minimum: food, territory. An example of this form of ecological interaction is the feeding of birds belonging to different species on the same tree, but in different tiers.

Thus, interspecific competition is in biology a kind of interaction between organisms that leads to:

  • to the cardinal division of populations of different species according to mismatched ecological niches;
  • to the expulsion of one less plastic species from biogeocenosis;
  • to complete ellimanation of the individuals of the population of the competing taxon.

Ecological niche and its limitations related to interspecific competition

Environmental studies have established thatBiogeocenoses consist of so many ecological niches, how many species live in the ecosystem. The more closely the ecological niches of communities of important taxa in the biotope are, the more bitter their struggle for the best environmental conditions:

  • territory;
  • fodder base;
  • population residence time.

These are the three main parameters of a real populatedecological niche. It fixes the limitations of the mode of existence of the population, such as parasitism, competition, predation, narrowing of the range, a decrease in feed resources.

interspecies competition

The decrease in the ambient pressure in the biotope occurs as follows:

  • tiered in a mixed forest;
  • various habitats of larvae and adultsindividuals. So, in dragonflies naiads live on aquatic plants, and adults have mastered the air environment; in the May beetle, the larvae live in the upper layers of the soil, and the adult insects live in terrestrial airspace.

All these phenomena characterize such a thing as interspecific competition. Examples of animals and plants, mentioned above, confirm this.

Results of interspecific competition

We consider a widespread phenomenonin living nature, characterized as interspecific competition. Examples - biology and ecology (as its section) - present this process to us both in the environment of organisms belonging to the kingdoms of fungi and plants, and in the animal kingdom.

The results of interspecific competition includecoexistence and substitution of species, as well as environmental differentiation. The first phenomenon is stretched in time, and related species in the ecosystem do not increase their number, since there is a specific factor affecting the reproduction of the population. The substitution of species, based on the patterns of competitive exclusion, is an extreme form of pressure of a more plastic and sertile species, which inevitably entails the death of a competitor.

interspecific competition is

Environmental differentiation (divergence)leads to the formation of little-changing, highly specialized species. They are adapted to those areas of the general area where they have advantages (in terms and forms of reproduction, nutrition).

In the process of differentiation, both competing speciesreduce their hereditary variability and seek a more conservative gene pool. This is because in such communities the stabilizing form of natural selection will dominate the moving and disruptive species.

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