Abstract ecological niches. Ecological niches of animals Description of the ecological niche
Ministry of Education and Science of the Russian Federation
Federal State Budgetary Educational Institution
higher professional education
"Siberian State Industrial University"
Department of Ecology
discipline: Social ecology
on the topic: “Ecological niche”
Completed:
Student gr. ERM-12
Belichenko Ya.V.
Checked:
Assoc. Dugin
Novokuznetsk
Introduction……………………………………………………..……………….…. 3
1. Ecological niche…………………………….………………………............ 4
1.1. The concept of an ecological niche……………….…………………………. 4
1.2. Width and overlap of niches…………………….………………………. 5
1.3. Evolution of niches………………………………………….……………….…10
2. Aspects of the ecological niche…………………………….……………….….12
3. Modern concept of ecological niche……………..……….............. 13
Conclusion……………………………………………………….………………………… 16
List of references………………………………….………...... 19
Introduction
This work discusses the topic “Ecological niches”. An ecological niche is the place occupied by a species (more precisely, its population) in a community, the complex of its biocenotic connections and requirements for abiotic environmental factors. This term was coined in 1927 by Charles Elton. An ecological niche is the sum of factors for the existence of a given species, the main one of which is its place in the food chain.
An ecological niche is the position occupied by a species in a community. The interaction of a given species (population) with partners in the community of which it is a member determines its place in the cycle of substances determined by food and competitive relationships in the biocenosis. The term “Ecological niche” was proposed by the American scientist J. Grinnell (1917). The interpretation of an ecological niche as the position of a species for the purpose of feeding one or several biocenoses was given by the English ecologist C. Elton (1927). Such an interpretation of the concept of ecological niche allows us to give a quantitative description of the ecological niche for each species or for its individual populations. To do this, the abundance of the species (number of individuals or biomass) is compared in the coordinate system with indicators of temperature, humidity or any other environmental factor.
In this way, it is possible to identify the optimum zone and the limits of deviations tolerated by the type - the maximum and minimum of each factor or set of factors. As a rule, each species occupies a certain ecological niche, to which it is adapted throughout the course of evolutionary development. The place occupied by a species (its population) in space (spatial ecological niche) is more often called habitat.
Let's take a closer look at ecological niches.
Ecological niche
Any type of organism is adapted to certain conditions of existence and cannot arbitrarily change its habitat, diet, feeding time, breeding place, shelter, etc. The whole complex of relationships to such factors determines the place that nature has allocated to a given organism and the role that it must play in the general life process. All this comes together in the concept of an ecological niche.
1.1.The concept of an ecological niche
An ecological niche is understood as the place of an organism in nature and the entire way of its life activity, its life status, fixed in its organization and adaptations.
At different times, different meanings were attributed to the concept of an ecological niche. At first, the word “niche” denoted the basic unit of distribution of a species within the space of an ecosystem, dictated by the structural and instinctive limitations of a given species. For example, squirrels live in trees, moose live on the ground, some bird species nest on branches, others in hollows, etc. Here the concept of ecological niche is interpreted mainly as a habitat, or spatial niche. Later, the term “niche” was given the meaning of “the functional status of an organism in a community.” This mainly concerned the place of a given species in the trophic structure of the ecosystem: type of food, time and place of feeding, who is a predator for a given organism, etc. This is now called the trophic niche. Then it was shown that a niche can be considered as a kind of hypervolume in a multidimensional space built on the basis of environmental factors. This hypervolume limited the range of factors in which a given species could exist (hyperdimensional niche).
That is, in the modern understanding of an ecological niche, at least three aspects can be distinguished: the physical space occupied by an organism in nature (habitat), its relationship to environmental factors and to neighboring living organisms (connections), as well as its functional role in the ecosystem. All these aspects are manifested through the structure of the organism, its adaptations, instincts, life cycles, life “interests”, etc. The right of an organism to choose its ecological niche is limited by a rather narrow framework assigned to it from birth. However, its descendants can claim other ecological niches if appropriate genetic changes have occurred in them.
Charles Elton.
An ecological niche is the sum of factors for the existence of a given species, the main one of which is its place in the food chain.
The principle of repression
The essence of the principle of repression, also known as Gause's principle, is that each species has its own ecological niche. No two different species can occupy the same ecological niche. Gause's principle formulated in this way has been criticized. For example, one of the well-known contradictions to this principle is the plankton paradox. All types of living organisms belonging to plankton live in a very limited space and consume resources of one kind (mainly solar energy and marine mineral compounds). A modern approach to the problem of sharing an ecological niche by several species indicates that in some cases two species can share the same ecological niche, and in some such combination leads one of the species to extinction.
Filling principle
An ecological niche cannot be empty. If a niche becomes empty as a result of the extinction of a species, it is immediately filled by another species.
Human ecological niche
Man as a biological species occupies his own ecological niche. Humans can live in the tropics and subtropics, at altitudes up to 3-3.5 km above sea level. In reality, nowadays people live in much larger spaces. Man has expanded the free ecological niche through the use of various devices: housing, clothing, fire, etc.
Wikimedia Foundation. 2010.
See what a “biological niche” is in other dictionaries:
Biological psychiatry is an approach in psychiatry, the purpose of which is to study the biological causes (etiology) and mechanisms of development (pathogenesis) of mental disorders, as well as biological methods of their treatment and correction. Research... ...Wikipedia
Ecology (from the Greek οικος house, economy, dwelling and λόγος doctrine) is a science that studies the relationships between living and inanimate nature. The term was first proposed in the book “General Morphologie der Organismen” in 1866... ... Wikipedia
Introduction The modern reader of popular military technical publications is spoiled by an abundance of materials on the history of creation, combat use, and design features of weapons and military equipment. My experience of communicating with fans of military equipment... ... Encyclopedia of technology
Human embryonic stem cells under a microscope. Stem cells are undifferentiated (immature) cells found in all ... Wikipedia
- (from the Greek óikos dwelling, residence and ... Logia) biological science that studies the organization and functioning of supraorganismal systems at various levels: populations, species, biocenoses (communities), ecosystems, biogeocenoses and the biosphere.... ...
- (from ancient Greek οἶκος dwelling, dwelling, house, property and λόγος concept, doctrine, science) the science of the interactions of living organisms and their communities with each other and with the environment. The term was first proposed by the German biologist Ernst... ... Wikipedia
This term has other meanings, see Nature (meanings). Nature is the material world of the Universe, in essence the main object of study of the natural sciences. In everyday life, the word “nature” is often used to mean natural environment... ... Wikipedia
Ecosystem, or ecological system (from ancient Greek οἶκος dwelling, residence and σύστημα system) a biological system consisting of a community of living organisms (biocenosis), their habitat (biotope), a system of connections, ... ... Wikipedia
- (from Bio... and Greek koinós general) a collection of plants, animals, microorganisms that inhabit a land area or body of water and are characterized by certain relationships both among themselves and with abiotic factors (See Abiotic ... ... Great Soviet Encyclopedia
Abstract on ecology
Any species is adapted to certain environmental conditions (factors). When the parameters of at least one of many factors go beyond the body’s tolerance limits, it becomes depressed. The organism's requirements for the composition and parameters of environmental factors inherited from its ancestors determine the distribution boundaries of the species to which this organism belongs, i.e., the area, and within the area - specific habitats.
In other words, any type of animal, plant, or microorganism is capable of normally living, feeding, and reproducing only in the place where evolution has “prescribed” it for many millennia, starting with its ancestors. To designate this phenomenon, biologists have borrowed the architectural term “niche.” Thus, each type of living organism occupies its own ecological niche in nature, unique to it.
Ecological niche - this is the place of an organism in nature and the entire way of its life activity or, as they say, life status, including relationships to environmental factors, types of food, time and methods of feeding, places of reproduction, shelters, etc. This concept is much broader and more meaningful than the concept of “habitat”.
Habitat is a spatially limited set of conditions of the abiotic and biotic environment that ensures the entire development cycle of the organism.
The American ecologist Yu. Odum figuratively called the habitat the “address” of an organism, and the ecological niche its “profession.” As a rule, a large number of organisms of different species live in one habitat. For example, a mixed forest is a habitat for hundreds of species of organisms, but each of them has its own ecological niche. An ecological niche is the functional role of a species in its place of residence. On the one hand, the organism is a participant in the general flow of life in its environment, and on the other, it is the creator of such a flow. And this is indeed very similar to a person’s profession.
First of all, an ecological niche cannot be occupied by two or more species, just as there are no two absolutely identical professions. A species occupies an ecological niche in order to perform a unique function in its own unique way, thus mastering the habitat and at the same time shaping it. Nature is very economical - even just two species occupying the same ecological niche cannot coexist sustainably, since as a result of competition one of them will be replaced by the other. This pattern is not without exceptions, but it is so objective that it is formulated in the form of a position called the “principle of competitive exclusion” (the principle of G.F. Gause): if two species with similar requirements for the environment (nutrition, behavior, breeding sites, etc.) enter into a competitive relationship, then one of them must die or change its lifestyle and occupy a new ecological niche . Sometimes, for example, in order to relieve intense competitive relations, it is enough for one organism (animal) to change the feeding time without changing the type of food itself (if competition arises on the basis of food relations), or to find a new habitat (if competition takes place on the basis of this factor) and etc. If organisms occupy different ecological niches, they usually do not enter into competitive relationships; their spheres of activity and influence are separated. In this case, the relationship is considered neutral.
An ecological niche as a functional place of a species in the system of life cannot remain empty for a long time, as evidenced by the rule of mandatory filling of ecological niches: an empty ecological niche is always naturally filled .
Among other properties of ecological niches, we note that an organism (species) can change them throughout its life cycle. The most striking example in this regard is insects. Thus, the ecological niche of the cockchafer larvae is associated with the soil and feeding on the root systems of plants. At the same time, the ecological niche of beetles is associated with the terrestrial environment, feeding on green parts of plants.
Communities of living organisms are formed according to the principle of filling ecological niches. In a natural established community, usually all niches are occupied. It is in such communities, for example, in long-standing (indigenous) forests, that the likelihood of introducing new species is very low. At the same time, it should be borne in mind that the occupation of ecological niches is to a certain extent a relative concept. All niches are usually occupied by those organisms that are characteristic of a given region. But if an organism comes from outside (for example, seeds are introduced) accidentally or intentionally, then it can find a free niche for itself due to the fact that there were no contenders for it from the set of existing species. In this case, a rapid increase in the number (outbreak) of the alien species is usually inevitable, since it finds extremely favorable conditions (a free niche) and, in particular, has no enemies.
An ecological niche as a functional place of a species in its habitat allows a form capable of developing new adaptations to fill this niche, but sometimes this requires considerable time. Often, empty ecological niches that seem empty to a specialist are just a deception. Therefore, a person should be extremely careful with conclusions about the possibility of filling these niches through acclimatization. Acclimatization is a set of measures to introduce a species into new habitats, carried out in order to enrich natural or artificial communities with organisms useful to humans. The heyday of acclimatization occurred in the 20-40s of the twentieth century. However, as time passed, it became obvious that either the experiments were unsuccessful, or, worse, brought very negative results - the species became pests, spread dangerous diseases, etc. It could not have been otherwise: placed in a foreign environment with an ecological niche actually occupied, new species displaced those who were already doing similar work. New species did not meet the needs of the ecosystem, sometimes had no enemies and therefore could reproduce rapidly. But then limiting factors came into play. The number of the species fell sharply or, on the contrary, it multiplied intensively, like the rabbit in Australia, and became a pest.
Each organism is influenced by various environmental conditions during its existence. These can be factors of living or inanimate nature. Under their influence, through adaptation, each species takes its place - its own ecological niche.
general characteristics
A general characteristic of the cell occupied by an animal or plant consists of defining and describing its model.
An ecological niche is a place occupied by a species or individual organism in a biocenosis. It is determined taking into account a complex of biocenotic connections, abiotic and biotic factors of the habitat. There are many interpretations of this term. According to the definitions of various scientists, the ecological niche is also called spatial or trophic. This is because, settling in his cell, the individual occupies the territory he needs and creates his own food chains.
The hypervolume model created by J. E. Hutchence is currently dominant. It is a cube, on its axes there are environmental factors that have their own range (valency). The scientist divided the niches into 2 groups:
- Fundamental ones are those that create optimal conditions and are equipped with the necessary resources to support the life of the population.
- Realized. They have a number of properties that are determined by competing species.
Characteristics of ecological niches
The characteristics of ecological niches include three main components:
- Behavioral characteristic is the way a particular type reacts to stimuli. And also how it gets food, the features of its shelter from enemies, its adaptability to abiotic factors (for example, the ability to withstand cold or heat).
- Spatial characteristics. These are the coordinates of the population location. For example, penguins live in Antarctica, New Zealand, and South America.
- Temporary. It describes the activity of species in a certain period of time: day, year, season.
The principle of competitive exclusion
The principle of competitive exclusion states that there are as many ecological niches as there are species of different organisms. Its author is the famous scientist Gause. He discovered patterns while working with different species of ciliates. The scientist first grew the organisms in monoculture, studying their density and feeding method, and later combined the species for breeding in one container. It was noticed that each species significantly decreased in number, and as a result of the struggle for food, each organism occupied its own ecological niche.
It cannot be that two different species occupy the same cell in a biocenosis. To become a winner in this competition, one of the species must have some advantage over the other, be more adapted to environmental factors, since even very similar species always have some differences.
Law of Constancy
The law of constancy is based on the theory that the biomass of all organisms on the planet should remain unchanged. This statement was confirmed by V.I. Vernadsky. He, the founder of the doctrine of the biosphere and noosphere, was able to prove that with an increase or decrease in the number of organisms in one niche, it is necessarily compensated for in another.
This means that an extinct species is replaced by any other that can easily and quickly adapt to environmental conditions and increase its numbers. Or, conversely, with a significant increase in the number of some organisms, the number of others decreases.
Mandatory Completion Rule
The mandatory filling rule states that an ecological niche never remains empty. When a species goes extinct for any reason, another immediately takes its place. The organism that occupies the cell enters into competition. If he turns out to be weaker, he is forced out of the territory and is forced to look for another place to settle.
Ways of coexistence of organisms
Methods of coexistence of organisms can be divided into positive ones - those that benefit all organisms, and negative ones, which benefit only one species. The former are called “symbiosis”, the latter – “mutualism”.
Commensalism is a relationship in which organisms do not harm each other, but also do not help. Can be intraspecific and interspecific.
Amensalism is an interspecific method of coexistence in which one species is oppressed by another. At the same time, one of them does not receive the required amount of nutrients, which is why its growth and development slow down.
Predation - predator species with this method of coexistence feed on the body of the victims.
Competition can be within the same species or between different ones. It appears when organisms need the same food or territory with optimal climatic conditions for them.
Evolution of human ecological niches
The evolution of human ecological niches began with the period of the existence of archanthropes. They led a collective way of life, using only those abundances of nature that were maximally accessible to them. The consumption of animal food during this period of existence was reduced to a minimum. To search for food, archanthropes had to develop a large amount of feeding territory.
After man mastered the tools of labor, people began to hunt, thereby having a significant impact on the environment. As soon as a person obtained fire, he made the transition to the next stage of development. After the increase in population, agriculture arose as one of the ways to adapt to food shortages in places where natural resources were almost depleted by intensive hunting and gathering. During the same period, cattle breeding emerged. This led to a sedentary way of life.
Then nomadic cattle breeding arose. As a result of human nomadic activity, a huge amount of pastures is depleted, this forces nomads to move and develop more and more new lands.
Human ecological niche
The ecological niche of a person changes along with changes in the way people live. Homo sapiens differs from other living organisms in its ability to articulate speech, abstract thinking, and a high level of development of material and intangible culture.
Man as a biological species was distributed in the tropics and subtropics, in places where the altitude above sea level was up to 3-3.5 km. Due to certain features endowed with man, his habitat has greatly increased in size. But as far as the fundamental ecological niche is concerned, it has remained virtually unchanged. Human existence becomes more complicated outside the original space; he has to confront various unfavorable factors. This is possible not only through the adaptation process, but also through the invention of various protective mechanisms and devices. For example, man invented different types of heating systems to combat such an abiotic factor as cold.
Thus, we can conclude that the ecological niche is occupied by each organism after competition and adheres to certain rules. It must have an optimal area of territory, suitable climatic conditions and be provided with living organisms that are part of the food chain of the dominant species. All living beings that are within a niche necessarily interact.
Ecological niche — the place of a species in the biogeocenosis, determined by its biotic potential and the totality of environmental factors to which it is adapted. This is not only the physical space occupied by an organism, but also its functional role in the community (position in the food chain), and its place relative to external factors.
There are 3 components in the structure of an ecological niche:
- Spatial niche (habitat) is the “address” of an organism;
- Trophic niche - characteristic feeding habits and the role of the species in the community - “profession”;
- A multidimensional (hyperdimensional) ecological niche is the range of all conditions under which an individual or population lives and reproduces.
Distinguish fundamental (potential) niche, which an organism or species could occupy in the absence of competition, predators, in which abiotic conditions are optimal; And realized niche- the actual range of conditions for the existence of an organism, which is less than or equal to the fundamental niche.
The rule of obligatory filling of the ecological niche.
An empty ecological niche is always and always naturally filled. In saturated biogeocenoses, life resources are used most fully - all ecological niches are occupied in them. In unsaturated biogeocenoses, vital resources are partially utilized; they are characterized by the presence of free ecological niches.
Ecological duplication- occupation of a vacated ecological niche by another species capable of performing the same functions in the community as the extinct species. It follows from this that knowing the distribution of species by ecological niche in a community and the parameters of each ecological niche, it is possible to describe in advance the species that will be able to occupy a particular niche if it becomes vacant.
Environmental diversification- the phenomenon of division of an ecological niche as a result of interspecific competition. It is carried out according to three parameters:
- by spatial arrangement
- according to diet
- according to the distribution of activity over time.
As a result of diversification, a shift in characteristics occurs—individuals of two closely related species are more similar to each other in those parts of their ranges where they are found separately than in areas where they live together.
Characteristics of an ecological niche:
1. Width
2. Overlapping a given niche with neighboring ones
Ecological niche width- a relative parameter that is assessed by comparison with the width of the ecological niche of other species. Eurybionts usually have wider ecological niches than stenobionts. However, the same ecological niche can have different widths in different directions: for example, in spatial distribution, food connections, etc.
Overlapping the ecological niche occurs when different species use the same resources when living together. The overlap can be complete or partial, according to one or more parameters of the ecological niche.
If the ecological niches of organisms of two species are very different from each other, then these species, having the same habitat, do not compete with each other (Fig. 3).
If ecological niches partially overlap (Fig. 2), then their joint coexistence will be possible due to the presence of specific adaptations in each species.
If the ecological niche of one species includes the ecological niche of another (Fig. 1), then intense competition occurs; the dominant competitor will displace its rival to the periphery of the fitness zone.
Competition has important environmental consequences. In nature, individuals of each species are simultaneously subject to interspecific and intraspecific competition. Interspecific in its consequences is the opposite of intraspecific, since it narrows the area of habitats and the quantity and quality of necessary environmental resources.
Intraspecific competition contributes to the territorial distribution of species, that is, the expansion of the spatial ecological niche. The end result is the ratio of interspecific and intraspecific competition. If interspecific competition is greater, then the range of a given species decreases to an area with optimal conditions and at the same time the specialization of the species increases.
