In ecology, a niche ( CanE , UK: or US: ) is the suitability of species living in certain environmental conditions. Ecological ecologists describe how organisms or populations respond to the distribution of resources and competitors (eg, with increasing resources abundant, and when predators, parasites and pathogens are scarce) and how it in turn alters the same factors (eg, limiting access to resources by other organisms, acting as a food source for predators and consumers of prey). "The types and quantities of variables that comprise the dimensions of an environmental niche vary from one species to another [and] the relative importance of specific environmental variables for a species may vary according to the geographic and biotic context".
A Grinnellian niche is determined by the habitat in which the species live and the adaptation of the accompanying behaviors. An Eltonian niche stresses that a species not only grows and responds to the environment, it can also change its environment and behavior as it grows. Hutchinson's cavity uses math and statistics to try to explain how species coexist in certain communities.
The idea of ​​ecological niches is the center of ecological biogeography, which focuses on the spatial patterns of the ecological community. "The distribution of species and their dynamics over time results from the nature of the species, the variations in the environment... and the interaction between the two - in particular the ability of some species, especially our own species, to change their environment and change the dynamic range of many other species. "The change of ecological niche by its inhabitants is a topic of niche construction.
The majority of species exist in standard ecological niches, sharing behaviors, adaptations, and functional properties similar to other closely related species in the same broad taxonomic class, but there are exceptions. A prime example of a non-standard niche filler species is the non-flying and ground-dwelling New Zealand kiwi, which feeds on worms and other land creatures, and lives its life in a mammal-like niche. The biogeography of the island can help explain the island species and the unfilled niche.
Video Ecological niche
niche Grinnellian
The ecological significance of the niche comes from the meaning of a niche as a recess in the wall for a statue, which may itself derive from the French word Central better , which means to nest . The term was coined by the naturalist Roswell Hill Johnson but Joseph Grinnell was probably the first to use it in a research program in 1917, in his paper "The niche relationship of Thrasher California".
The concept of the Grinnellian niche embodies the idea that the species niche is determined by the habitat of residence and the adaptation of the accompanying behavior. In other words, a niche is the sum of the habitat and behavioral requirements that allow a species to survive and produce offspring. For example, California's thrasher behavior is consistent with the living chaparral habitat - it breeds and feeds in bushes and escapes from its predators by dragging from the bushes into the bushes. 'Niche' is defined by the perfect complement of thrasher behavior and physical properties (color disguise, short wings, strong legs) with this habitat.
This niche perspective enables the existence of ecologically equivalent and empty niches. An ecology equivalent to an organism is an organism of a different taxonomic group that exhibits similar adaptations in the same habitat, for example the different succulents found in the American and African deserts, cactus and euphorbia, respectively. As another example, the anole lizard of the Greater Antilles is a rare example of convergent evolution, adaptive radiation, and ecologically equal existence: the anole lizards evolved in the same microhabitats independently of each other and produced the same ecomorphs across all four islands..
Maps Ecological niche
Niche Eltonian
In 1927 Charles Sutherland Elton, a British ecologist, defined the following niche: "The 'niche' of the animal means its place in the biotic environment, its relationship to food and enemies."
Elton classifies a niche based on feeding activities ("eating habits"):
For example there is a niche filled by birds of prey that feed on small animals such as rats and mice. Inside a niche oak grooves are filled by tawny owls, while the open grassland is occupied by kestrels. The existence of this carnivorous niche depends on the further fact that rodents form a definite herbivorous niche in many different associations, although the actual species of the mice may be very different.
Conceptually, the Eltonian niche introduces the notion of response responses to and effects on the environment. Unlike other niche concepts, he emphasizes that a species not only grows and responds to the environment based on available resources, predators and climatic conditions, but also changes the availability and behavior of these factors as they grow. In extreme instances, beavers require certain resources to survive and reproduce, but also build dams that alter the flow of water in rivers where live beavers are. Thus, the beaver affects the biotic and abiotic conditions of other species living in and near the watershed. In the more subtle cases, competitors who consume resources at different rates can cause different resource density cycles between species. Not only do species grow differently with respect to resource density, but their own population growth can affect resource density over time.
Niche hutchinson
Niche Hutchinson is the "hypervolume n-dimension", in which dimension is the condition of the environment and resources, which determines the individual or species requirements to practice his "way of life, more specifically, for his inhabitants to survive. The "hypervolume" defines the multi-dimensional spaces of resources (eg, light, nutrients, structures, etc.) available to (and specifically used by) organisms, and "all other species other than those considered as part of the system coordinates."
The concept of the niche was popularized by zoologist G. Evelyn Hutchinson in 1957. Hutchinson asked the question why there are so many types of organisms in one of the habitats. His work inspires many others to develop models to explain how and how similar species coexist within a particular community, and lead to the concept of a 'niche of bread' (the resources or habitats used by a particular species), the 'partition niche' (resource differentiation by coexisting species), and 'niche overlap' (overlapping resource use by different species).
Statistics introduced into Hutchinson's niche by Robert MacArthur and Richard Levins use a 'resource utilization' niche using a histogram to describe the 'frequency of occurrence' as a function of the Hutchinson coordinates. Thus, for example, a Gaussian might describe the frequency at which a species feeds on a prey with a certain size, giving a more detailed description of the niche than just determining the average or average size of the prey. For such bell-shaped distributions, positions , width and forms of niches corresponding to mean , standard deviation and the actual distribution itself. One advantage of using statistics is illustrated in the figure, where it is clear that for a narrower distribution (above) there is no competition for prey between extreme left and extreme right species, while for wider distribution (bottom), niche overlaps indicate competition can occurs among all species. The resource utilization approach consists in postulating that not only competition can occur, but also that it does not occur, and overlapping in direct resource utilization allows the estimation of the coefficient of competition. This postulate, however, can be misdirected, because it ignores the impact that the resources of each category have the organism and the impact that the organism has on the resources of each category. For example, resources in overlapping areas can be unlimited, in this case there is no competition for these resources even though there is overlapping niche.
Disorder-free organisms from other species may use a variety of conditions (biotic and abiotic) and the resources in which it can survive and reproduce so-called fundamental niches . However, as a result of pressure from, and interaction with, other organisms (ie inter-specific competition) species are usually forced to occupy a niche that is narrower than this, and where they are largely highly adaptable; this is called a realized niche. Hutchinson uses the notion of competition for resources as the primary driving mechanism of ecology, but the overemphasis on this focus has proven to be flawed for niche concepts. In particular, the overemphasis on species dependence on resources has caused too little emphasis on the effects of organisms on their environment, for example, colonization and invasion.
The term "adaptive zone" was created by paleontologist George Gaylord Simpson to explain how a population can jump from one niche to another suitable niche, jumping into the 'adaptive zone', available by modification, or perhaps change. in the food chain, which makes the adaptive zone available to it without any discontinuities in the way of life because the group is 'pre-adaptation' to new ecological opportunities.
"Niche" Hutchinson (the description of the ecological space occupied by a species) is subtly different from the "niche" as defined by Grinnell (ecological role, which may or may not be completely populated by species - see empty niches).
A niche is a very specialized ecospace segment that is occupied by one species. Assuming that no two species are identical in all respects (called the 'axioms of inequality' of Hardin) and the principle of competitive exceptions, some resources or adaptive dimensions will provide a special niche for each species. However, species may share a 'life mode' or 'autecological strategy' which is a broader definition of ecospace. For example, Australian grassland species, though different from the Great Plains grasslands, exhibit similar modes of life.
Once the niche is left empty, other organisms can fill that position. For example, a niche left empty by the tarpan extinction has been filled by other animals (especially small horses, conic). Also, when plants and animals are introduced into new environments, they have the potential to occupy or invade niches or niches from native organisms, often competing with native species. The introduction of non-native species to non-native habitats by humans often results in biological contamination by exotic or invasive species.
The mathematical representation of the fundamental niche of a species in the ecological space, and the subsequent projection back to the geographical space, is the niche modeling domain.
Parameters
Different dimensions, or plot axes, of the niche represent different biotic and abiotic variables. These factors may include descriptions of the life history of organisms, habitats, trophic positions (places in the food chain), and geographical range. According to the principle of competitive exclusion, no two species can occupy the same niche in the same environment for a long time. The parameters of the realized niche are explained by the width of the realized niche of the species. Some plants and animals, called specialists, need habitats and special environments for survival, such as spotted owls, which live exclusively in old growth forests. Plants and other animals, called generalists, are not very specialized and can survive under various conditions, such as dandelions.
See also
- Fitness landscape
- Niche distinction
- Excess Population
- Phylogenetic religious tolerance
- Neutral theory of neutral biodiversity
References
External links
- Ecological niche concept
- Niche Environment - Extinction of Dinosaurs
- The ontology of the niche
- Niche boundaries and segregation
- Goal is blank
- Width width hypothesis
Source of the article : Wikipedia
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