What factors determine the distribution of animals?
Biotic factors such as predation, disease, and inter- and intra-specific competition for resources such as food, water, and mates
can also affect how a species is distributed.
What is the distribution of plants and animals?
biogeography, the study of the geographic distribution of plants, animals, and other forms of life.
What are barriers of animal distribution?
The biotic barriers include
food, enemies and competition from other living organisms
. (i) Food: Certain arthropods (Aphid) depend upon a particular species of plant for their food, shelter and breeding place. Hence, absence of that plant in a particular area acts as a barrier for the distribution of such arthropods.
Which of the following factors affect species distribution?
Species distributions are dependent on interactions with
abiotic and biotic factors
in the environment. Abiotic factors like temperature, moisture, and soil nutrients, along with biotic interactions within and between species, can all have strong influences on spatial distributions of plants and animals.
What is geographic distribution of living species?
Biogeography is
the study of the geographic distribution of living things and the abiotic factors that affect their distribution
. Abiotic factors, such as temperature and rainfall, vary based on latitude and elevation, primarily.
Abiotic Factors and Tolerance Limits
Most species appear to be limited in at least part of their geographic range by abiotic factors, such as temperature, moisture availability, and soil nutrients
. No species is adapted to survive under all conditions found on the Earth.
The Geographical Distribution of Animals, with a Study of the Living and Extinct Faunas, as Elucidating the Past Changes of the Earth’s Surface. By
Alfred Russel Wallace
. Two Vols, 8vo. (London: Macmillan and Co., 1876.)
Species distribution models
Based on factors of dispersal, disturbance, resources limiting climate, and other species distribution
, predictions of species distribution can create a bio-climate range, or bio-climate envelope.
Most plants and animals live in areas with very specific climate conditions, such as temperature and rainfall patterns, that enable them to thrive.
Any change in the climate of an area can affect the plants and animals living there, as well as the makeup of the entire ecosystem.
Dispersal
allows animals to avoid competition, avoid inbreeding,
69
and to colonize new habitats
. Animals disperse by leaving their natal area and finding new territories or home ranges. The dispersing animal, like the migrating one, is attempting to improve its lot in life by finding a suitable habitat.
They can also influence the distribution of organisms in an ecosystem. Examples of biotic factors are:
competition for environmental resources
.
grazing – too little leads to dominant plants outcompeting other species, too much reduces species numbers overall
.
Definition of geographical distribution
:
the natural arrangement and apportionment of the various forms of animals and plants in the different regions and localities of the earth
.
The abiotic factors will define which organisms are able or not to live in a specified place. The living organisms will constitute the biotic factors, which define if and how can an organism live in a specified environment. So,
the abiotic factors are controling the biotic factors of an environment
.
External factors include both natural and human factors
. Natural factors refer to the ecological environment, including climate, topography, soil, and other biological factors [11], [12]. For example, many rare and endangered plants are only distributed in narrow area with a special microclimate.
A number of evolutionary processes such as
selection, gene flow, and historical demography
affect the genetic diversity in a population (Hayes and Fox 1991; Boettcher et al. 1995; Bazin et al. 2006). The genetic diversity of individuals within a population affects a range of ecological and evolutionary factors.
Both the biotic and abiotic factors play their role
to create a unique ecosystem
. As it is clear now that the biotic factor refers to a living thing, thus it is obvious that they need a certain amount of energy, food, and environment to function properly. They get their energy and nutrition from their environment.
1.
Brown’s theory of centrifugal speciation
. It has been observed that largest populations of a species exist in the most favourable areas. Due to increasing numbers in these areas a population pressure may build up forcing some pioneers to venture into the peripheral areas which may not be as habitable.
Several factors contribute to species diversity, including
habitat diversity, competition among species, and genetic diversity
. Genetic diversity within a species not only is necessary to maintain diversity among species,
6
but also contributes to the diversity of food, fiber, and medicines available from nature.
External factors include both natural and human factors
. Natural factors refer to the ecological environment, including climate, topography, soil, and other biological factors [11], [12]. For example, many rare and endangered plants are only distributed in narrow area with a special microclimate.
