Biotic Potential in Population Ecology

The biotic potential is the utmost reproductive capability of living organisms under environmental conditions. The biotic potential is the greatest possible vital index of species, hence, when the species has the highest birth rate and lowest mortality rate. There are primary factors that determine the biotic potential. These factors include organism rate of reproduction and its litter size - the number of offspring produced at one birth.

Under ideal environmental conditions, the capacity of a species to reproduce is known as its biotic potential. Therefore in any way, the food supply will not be limited and there will be no effect on the population of the disease and predation. The number of offspring produced and the frequency of reproduction are the two factors on which the biotic potential depends.

The biotic potential among organisms differs from species to species. Similar to humans, many large organisms produce one offspring throughout the year or during the breeding season. On other hand, insects can produce thousands of organisms each year. Hence, the organisms that are larger have relatively lower biotic potential in comparison to the smaller organisms. 

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Large variations among species are there in biotic potential. For instance, thousands of offspring can be reproduced by insects while it is not possible in the case of mammals. Most organisms are not able to reproduce or fulfill their biotic potential if ideal environmental conditions are not provided which may result in limitation of food or the diseases might kill many members of the population. Humans choose to limit their reproduction frequency and have managed to reduce problems like these. Therefore, humans continue to grow.

Definition Of Biotic Potential

The biotic potential is defined by the ecologist R.N. Chapman has “ the inherent ability of an organism to reproduce and survive”.

Biotic potential was again redefined by the R.N. Chapman in 1993 as: “ it is kind of numerial sum of the number of young once born at each reproduction, the number of reproduction over some time, the sex ratio of the species, and the general capacity to survive under given physical conditions.

Biotic definition - Biology defines anything related to living organisms. The word ‘biotic’ is primarily used to explain affecting factors or situations in the environment of living organisms that are affected by other living organisms or biological entities.

What is the Biotic Environment?

The biological component of the environment is also known as the abiotic component of an environment. This biological component consists of all living organisms like plants, animals, and small microorganisms like bacteria. These biotic components interact with the abiotic components of an environment. The interaction of two components forms varied ecosystems like pond ecosystem, marine ecosystem, and desert ecosystem. The self-supporting large ecosystem of the Earth is known as the Biosphere.  All ecosystems consist of three different types of living organisms namely producers, consumers, and decomposers.

Producers are green plants and other photosynthetic bacterias which produce different organic substances such as protein, carbohydrates, etc. with the help of soil, water, and light energy. Consumers depend for their nutrition on the organic foods produced by green plants. A decomposer is an organism that decomposes or breaks down organic material such as the remains of dead animals and brings about various important minerals for the running of the biogeochemical cycles.

The three components of the environment such as physical, chemical, and biological bring about important zones. These are Atmosphere, Lithosphere, Hydrosphere, and Biosphere. There is constant interaction among these four zones. This interaction involves the transportation of various elements, compounds, and energy forms.  

Biotic Factors

A biotic factor is defined as a living organism that affects other organisms or shapes its environment. These include both animals that consume other organisms within their ecosystem and the organism that is consumed. Biotic factors include pathogens, human influence, and disease outbreaks.  

Living components that are present in the ecosystem are known as the biotic factors as the meaning of the word ‘biotic’ itself is related to a living organism. All living organisms and the physicochemical components constitute the ecosystem. The physical and chemical factors such as sunlight, temperature, and water are referred to as the abiotic factors while living components which include birds, bacteria, along with all the other living organisms that are present around us, are referred to as the biotic factors. 

Biotic Components are Typically Divided into Three Main Categories:

• Producers, also known as autotrophs convert energy into food through the process of photosynthesis 

• Consumers, also known as heterotrophs, depend on food (and often on other consumers).

• Decomposers (also known as detritivores) is a process of breaking down chemicals from producers and consumers (generally antibiotics) into simpler forms that can be reused. 

Biotic Factors Examples

The biotic factor examples in different ecosystems are as follows:

1.  Freshwater Ecosystem

• Fish

• Amphibians

• Aquatic plants

•  Algae

2. Marine Ecosystems

• Algae

• Bacteria

• Plant

• Coral

• Fish

• Sharks

• Jellyfish

• Planton

3. Terrestrial Ecosystem

• Fungi

• Mushroom

• Herbs

• Trees

• Soil Bacteria

• Shrubs

Types of Biotic Factors

Biotic factors on the basis of their distinctive roles are classified into three categories which include producers, consumers, and decomposers.

1. Producers (Autotrophs)

The biotic factors that are responsible for the production of food by using energy sources and inorganic materials are referred to as the producers. These play a very important role in the ecosystem and it might not be possible for life to exist without the biotic factors. These produce complex organic compounds which include carbohydrates, fats, and protein with the help of inorganic compounds which include carbon dioxide and water. Examples of some producers are algae and plants on water and land respectively. Producers can further be divided into two classes-

1. Photoautotrophs

2. Chemoautotrophs

2. Consumers (Heterotrophs) 

The biotic factors on which other living organisms rely upon as a source of food in order to obtain energy and to survive are referred to as consumers. These cannot make their own food and they take nutrition from plants or other animals. Examples of some consumers are bacteria, animals, fungi, and parasitic plants. The consumers can further be classified into primary, secondary, and tertiary consumers. The primary category includes consumers eating plants to survive and they are known as herbivores. The secondary category includes consumers eating herbivores or grass-eating animals only and are known as carnivores. The tertiary category includes consumers that eat both animals and plants and are known as omnivores. Therefore, rabbit is a primary consumer which is eaten by a snake which is further eaten by an owl. Here the snake and owl are secondary and tertiary consumers respectively. 

3. Decomposers

The biotic factors in the ecosystem that are responsible for the decomposition of plants, animals, and their feces are known as decomposers. These are placed at the bottom of the energy pyramid and these include arthropods, bacteria, slugs, and so on.

The quantitative expression of the biotic potential is the ability of an organism to face selection in any environment. The main equation of the specific population is derived by the equation.

Number of Individuals - Biotic/ Potential resistance of Environment (Biotic/ Abiotic).

According to R.N Chapman, a vital index refers to the ratio to find the rate of surviving members of a species, whereas 

Vital Index = Number of Birth/Number of Death × 100.

Did you Know

• A species that attains its biotic potential would exhibit exponential population growth and is said to have high fertility, i.e. the number of offspring produced by the mother.

• The term biotic potential is introduced by the ecologist R.N. Chapman.

• Environment resistance is the sum total of the factors that obstruct populations from continuously growing and hence aims to keep the population at a constant level. These factors are predators, disease, and a lack of supply of any essential requirement such as food, water, shelter, and light (which is specifically important for the growth of the plant).