[Biology Class Notes] on Biotic and Abiotic Factors Pdf

The term ecosystem was coined by A.G Tansley, an English botanist in 1935. It is known as both structural and functional units of the environment where both biotic and abiotic factors interact with each other to form a complete ecosystem. Thus we can say that ecosystems are made up of two components: they are biotic factors and abiotic factors and both these factors are equally important to maintain stability in the ecosystem. 

 

All living beings present in an ecosystem are known as biotic components whereas non-living components are known as abiotic components like physical conditions (temperature, humidity, salinity, sunlight, pH, etc). Interaction of both biotic and abiotic components are necessary to stability and chain linkage of the ecosystem and both of them are interdependent on each other for easy survival. Due to this reason, only extinction on any one component leads to an imbalance in the whole ecosystem.

 

Biotic Factors

The term biotic is made up of two terms: “bio” means living organism and “ic” means like, thus combined they are known as living organisms. Therefore it can also be defined as all living organisms present on earth are known as biotic components. 

 

Example: Plants, animals, human beings, decomposers, yeast, insects, etc. All these biotic components interact to develop new generations i.e to reproduce new organisms to maintain stability in the food chain. 

 

Examples of Biotic Factors

As biotic factors are in living form so there examples are also in living form. Some of the examples of biotic factors are listed below.

1. Producers are organisms which can make their own food by photosynthesis. Like plants, algae, bacteria.

2. They obtain their source of energy from abiotic factors like sunlight, humidity, water, etc. As all these factors are important for proper synthesis of food. 

3. Chlorophyll is present in the procedure and they absorb all these abiotic factors for synthesis of food. Part of synthesized food is utilized by producers only for their proper functioning and growth.

1. Organisms that feed on producers are known as consumers. 

2. Consumers are further divided into three or more types.

1. Primary Consumers: One who directly feeds on procedures are primary consumers. Example: cow, goat, etc. 

2. Secondary consumers: Consumers one who feeds on primary consumers are known as secondary consumers. Example: lion, tiger, etc.

1. Living organisms that break or decompose the dead bodies of plants and animals are known as decomposers.

2. They are heterotrophic in nature.

3. Example: fungi, bacteria, etc. 

4. Decomposers secrete enzymes of the decaying process due to this reason they are known as reducers.

1. An Organism who feeds on dead and decaying organisms are known as detritivores.

2. They get the least amount of energy after feeding. 

 

Abiotic Factor

Nonliving parts of an ecosystem are termed abiotic factors. They play a crucial role in shaping ecosystems as both biotic and abiotic factors interaction is a must for the stability of the ecosystem. 

 

Examples of Abiotic Factors

Most of the common examples of abiotic factors are air, weather, water, temperature, humidity, altitude, pH, level of soil, types of soil and more, water flow rate, water depth, etc. 

 

Energy Flow In Ecosystem

1. Energy flows from one trophic level to another trophic level is termed as energy flow and this flow of energy is always unidirectional in nature. This means the flow of energy takes place in sequential order i.e from producer’s primary consumers to secondary Consumer’s decomposer’s detritus. Due to this reason, energy cannot be reversed back. 

2. At the end of energy flow, it gets converted into minerals that can be used again and again.

3. Only 10% of total energy is used at each trophic level. Due to this Autotrophic organism gets the highest amount of energy in comparison to heterotrophs, decomposers, etc. As they directly feed on producers. This 10% law was given by Lindeman (1942 ).

 

Difference Between Biotic and Abiotic Components:

Brief Look at Some Abiotic Factors of an Ecosystem

Abiotic Factors are an important part of the ecosystem because of the roles they play in facilitating the flow of energy within the ecosystem. Given below are some brief descriptions of
Abiotic Factors in an ecosystem and their roles.

The climate refers to the weather conditions and general temperature of an ecosystem. This plays a huge role in the maintenance of the ecosystem through the regulation of the temperature and weather conditions. Any organisms living in a particular ecosystem evolve to suit that ecosystem, so even minute changes in climate can seriously impact the lives of the organisms living there. 

The pH balance of an ecosystem refers to the general level of acidity or alkalinity present in the environment. It is a scientific method of measuring whether a particular mixture or solution is acidic, neutral, or alkaline. Pure water has a pH of 7, meaning it is neutral. Acidic mixtures have a pH balance of less than 7 while alkaline mixtures have a pH balance of more than 7. This also affects the organisms in an environment, because many creatures or plants, or microorganisms cannot survive in certain pH ranges.

It may be interesting to note that even something as simple as the level of light present in an environment or ecosystem can greatly affect the organisms in that ecosystem. As you know, photosynthesis is the main form of energy consumption for plants, which means that all plants need a certain level of light to create their own food. Some plants in dark ecosystems have evolved to a point where they make do with minimal amounts of light, such as the plants found deep in the oceans where light doesn’t reach.

In an underwater or ocean ecosystem, water currents play a huge role in the regulation of the ecosystem. Water currents are some of the most important and useful parts of an oceanic ecosystem and at the same time also one of the most destructive. They are important because they redistribute minerals, nutrients, heat, oxygen, etc. However, strong ocean currents can also uproot and carry away plants and other organisms, which simultaneously destroys part of the ecosystem and also delivers a source of food to another part of the ecosystem.