Ecological niche: models and principles

Ecologists have to deal with different types of organisms: from cyanobacteria to elephants. It is clear that the habitat can be very different. Methods of study are also different. How can we study such heterogeneous phenomena? Is it possible to identify patterns? Yes, there is a special scientific toolkit, based on the concept of "ecological niche." Any branch of the science under discussion deals with this concept. So, let's see what it is.

The term itself was proposed very long ago, in the 20s of the 20th century. It was invented by a representative of a practical nation - American John Grinell. In his understanding, the "ecological niche" is a condition that is normal for living in a particular species. But Charles Elton, a Briton, formulated it, clarifying, in a different way. He said that the niche is a relationship with food and a relationship with natural enemies. There are two different approaches to the definition. In the first case, it means "address" (where he lives), in the second - "profession" (what he is doing in the community). But two different species can have the same function in different communities. For example, in Russia, large herbivores - moose, in Africa - antelopes, in Australia - kangaroos.

Americans did not have enough wide definition of the concept of "ecological niche." Therefore, in the 50's a scientist from this state, George Hutchinson, created a multidimensional model. Under the term, he proposed to consider the entire range of environmental factors in which the species lives. And for a long time. And at the same time it multiplies. Let us take an example of some kind of plant. Let us know that there are upper and lower temperature limits in which this species can live and feel good. These data can be represented as a coordinate system in which one of the axes can postpone the temperature. And the second axis will be humidity, the third, for example, the amount of nutrients. As a result, the graph will become a three-dimensional shape, like a box.

Hutchinson with the help of this model compared niches of different species of organisms. Imagine several such boxes in space. This allows us to clearly demonstrate some of the relationships of animals in space and their competition for food. For animals, the following indicators for the axes are usually used: spatial arrangement, nutrition and seasonality.

Some species are omnivorous and live in different places, and some eat monotonous food and live in strictly defined conditions. The more food options, the more "niche width" ecologists say. Say, a koala loves only the leaves of eucalyptus (and not all of them), and possums eat almost everything. Is it good when the ecological niche is wide? On the one hand, yes, because it allows you to adapt to changes in the environment. But if the environment is stable, then the situation is more profitable for those who use one type of food species. In addition, those who love diversity are usually less able to produce food than "narrow specialists".

Many species with similar niches have to compete hard for food. Therefore, almost never two species with similar niches in one community do not exist territorially, one will inevitably supplant the second. This was established experimentally by a scientist from Russia, Gauze. It turns out that herbivores of one territorial community eat different plants. And different predators - they hunt for completely different kinds of victims.

Often, the niches overlap, but the nutrition of the organisms must be different. Of course, for a normal functioning of the community niches in some respects must overlap, but there must always be room for flexibility, otherwise it is almost impossible for the species to survive.

The ecological niche of man is the widest and most extensive. We need to take care that next to us there is also space for the existence of other species. Nature does not tolerate neglect.