Introduction

Ecology is the science that deals with the mutual relationship between plants and animals and their relationship with the environment. There are 6 levels of ecological organization. These are as follows

1. Organisms
2. Populations
3. Biological community
4. Ecosystem
5. Biome
6. Biosphere.

These six levels of ecological organization are discussed in detail below.

Ecology critically analyzes the interpretation of all aspects of the biosphere. Ecological organization is a study of how organisms interact with each other and with their environments. So the levels are discussed in these interactions.

Basically, scientists study ecology at various levels of the organization. Ecological organization is a theoretical approach in social science. The environment is full of living things and their interactions. So they are discussed at different levels. The ecological levels are discussed by discussing ecology at different levels (1).

Definition

Ecological levels of the organization are defined as how the biological world at and above the level of the individual organism is organized into a social order, which provides a specific structure of reference to the study of ecology.

1. Organism

Definition

In the language of biology, all entities in the known universe that possess and exhibit the characteristics of life are called organisms.

Description

The main characteristics of organisms are movement, nutrition, excretion, reproduction, sensation, respiration, growth, and adaptation. Organisms consist of one or more cells containing protoplasm. They can reproduce by giving birth to new life similar to themselves. Organisms need food, water, and air to sustain their existence. So organisms are interdependent with non-living things in the environment.

Interesting facts

• Many organisms live on the earth’s surface.
• Every organism in the environment is different from the others in some way.
• Their structural characteristics are different.
• Each organism can be considered a life system.
• Their characteristics are such as response to stimuli, growth, development, reproduction, regulation, and energy processing.
• Organisms can be classified as prokaryotes and eukaryotes.
• Prokaryotes are those organisms whose body is made up of only one cell with no well-organized nucleus. The mechanism of action of prokaryotes organisms such as protozoa, algae, etc. is different from that of a normal cell.
• Bacteria, archaea, etc. are single-celled organisms. So they do not have membrane-bound organelles. All their functions are completed in one cell.
• Eukaryotic organisms consist of multiple cells. In eukaryotes, special types of cells form tissues with special characteristics in terms of structure and function.
• Tissues of eukaryote organisms collectively form organs. Organs form organ systems and organ systems form an organism.
• Every organism exchanges energy and matter with its surrounding non-living environment (through the intake of food and excretion of waste products) and thus the organism develops a functional relationship with its environment.
• Eukaryotes are organisms whose cells contain a nucleus and other membrane-bound organelles. They may be either single-celled or multi-celled (2).

2. Population

Definition

All organisms belonging to the same species collectively form a population. In biology, a population is all organisms of the same group or species that live and reproduce in a given geographic area.

• A sexual population area is an area where inbreeding is possible within a pair and is more likely than interbreeding with species from other areas.
• Each population is reproductively and biologically distinct from other populations.
• Population refers to the collection of people.
• Demography is a social science that involves the statistical study of the population.
• When considered on a large scale, a population can be defined as all individuals of a particular species living in a specific geographic area.
• Organisms make up a population.
• Biotic and abiotic components of a region are the main limiting factors for the growth of a population.
• The growth of the population is high due to birth or immigration and low due to death or emigration.
• The population is the study that discussed various factors that impact population growth, reproduction, risk of extinction, etc.
• This ecological level is the whole number of inhabitants occupying an area (3).

3. Biological Community

Definition

All the interrelated plant and animal groups in a particular habitat are collectively called biological communities. That is, the plants and animals that live in the same environment and maintain their individual existence by adapting to the environment and also maintaining interrelationships with other groups is known as community.

According to Grubb, “Community is a collection of plant populations found in one habitat type in one area and integrated to a degree by competition, complementarity and dependence”.

Example

The tropical rainforest is the largest biological community region in the world. Fish, salmon, herring, etc. coexist in a defined place forming a biological community.

Interesting facts

• Nowhere on the earth’s surface does the flora or fauna consist of only one species. That is, no single organism is purely present in any place. Different populations of organisms usually live together as a community.
• A community is formed by the collection of several populations.
• Considerable variety and diversity can be observed in a community. The community can be of various extents. For example, the fauna of a pond and the fauna of the Amazon River basin.
• A community like an organism adapts itself through constant interaction with its environment. Thus the community reflects its environment.
• The adaptation of a community is the overall result of the adaptation of each individual organism. But from a holistic point of view, the adaptation of the community is of a very high level.
• Adaptation of the entire community to the environment controls the structure and function of the community.
• A certain structure, development history, and ritual use can be observed in the community.
• The diversity of the community is variable with respect to the environment.
• Communities sustain their existence by adapting to the local environment.
• The growth and formation history of all communities is different (4).

4. Ecosystem

Definition

In 1935, A.G. Tansley was first used as an ecosystem term. The word ‘eco’ means environment, and ‘system’ means interdependent.

The special system in which the organisms of a habitat form a stable system or unit through mutual interaction with each other and with inorganic and organic components in the environment is called an ecosystem.

Factors or components

The components of the ecosystem are mainly divided into two types.

a. Abiotic components

Abiotic components are three types. These are inorganic components (carbon dioxide, oxygen, phosphorus, calcium, etc., organic components (carbohydrates, proteins, fats, humus, etc.), and physical components (water, wind, humidity, rainfall, topography, etc.

b. Biotic components

Biotic components are two types. These are Autotrophs and heterotrophs. Heterotrophs are of two types, consumer and decomposer. And consumers are three types, primary consumer, secondary consumer, and tertiary consumer. Autotrophs are the producers of the ecosystem.

Types

Ecosystems are two types. These are natural ecosystems and artificial ecosystems. Natural ecosystems are two types, such as terrestrial (forest, grassland, desert, etc.) and aquatic ecosystems.

Interesting facts

• The interactions and interrelationships of various living and non-living elements within an ecosystem proceed in a very complex type.
• An ecosystem is an open system. Because the system that operates within the ecosystem is a continuous exchange of energy and matter with the environment.
• It has a specific area.
• The supply and production of energy and matter in the ecosystem are active at all times.
• Sun is the only source of energy in the ecosystem.
• The size of an ecosystem can range from very small to large.
• The ecosystem has a well-organized specific structure.
• In an ecosystem, food chains, food webs, ecological pyramids, etc. can be observed. So every organism is related to each other through the food chain. No species present here can survive in isolation from each other (1) & (3).

5. Biome

Definition

The word biome comes from ‘bio’= life’, and ‘ome’= ‘mass’ or ‘body’.

In general, a complex region consisting of different plant and animal groups belonging to the same climatic zone is called a biome.

According to Whittaker, “biome is a grouping of terrestrial ecosystems on a given continent that are similar in vegetation structure, physiognomy, features of the environment and characteristics of their animal communities”.

A biome is the largest unit in an ecosystem. Plants and animals form biomes based on interactions with soil and climate. It is one of the largest ecosystems where different animals, plants, and insects live in the same climatic zone.

Interesting facts

• All the plants and animals in a region interact with each other and with the environment to form a biome.
• The role of climate in determining biomes is direct.
• A biome may be restricted to only one region.
• Homogenous biomes are observed in the presence of similar natural environments in different regions of the world.
• Biomes spread over a wide area.
• Terrestrial biomes are demarcated mainly on the basis of vegetation and the natural environment.
• Each biome has more producers.
• Ecotones are observed in the region between the two biomes.
• A single ecological biodiversity can be observed within a biome.
• Aquatic biomes are formed based on the assemblage of plants and animals in the water.
• All the animals, plants, and soil in an ecosystem help to make up the biome of a place.
• In terms of nature, regions of the world that share similar ecological characteristics belong to the same biome.
• There are mainly two categories of the biome. These are terrestrial biomes and aquatic biomes.

Importance

The biome is the largest unit of the ecosystem. A biome has a higher number of producers. Herbivores consume producers as food. And carnivores consume herbivores as food. In this way, food is transferred in a chain and ecosystems develop. The role of the biome behind the development of the ecosystem is very high (2).

6. Biosphere

Biosphere is the specific area on earth suitable for living organisms. In fact, the biosphere is from the level of the seafloor to the level of the atmosphere above the earth’s surface where the presence of living organisms can be observed.

Definition

The part of the crust, hydrosphere, lithosphere, and atmosphere where the creation, growth, and existence of living things can be observed is the biosphere.

According to J. Tivy, “The biosphere is that part of the world containing living organisms, the biologically inhabited soil, air and water”.

Interesting facts

The biosphere is the single largest ecosystem because there are many small ecosystems in it. It has no boundaries. The concentration of organisms is highest at an altitude of 300 m above the surface and at a depth of 200 m in the sea. It extends up to 10 m deep in the soil. In fact, the biosphere, like the lithosphere, the atmosphere, or the hydrosphere, has no definite boundaries.

The biosphere consists of living and nonliving elements. Just as the flora and fauna have evolved their natural environment through their millions of genes and species, they also maintain the balance of the environment by interacting with the inert elements. It is organized as an open system because the flow of energy in the biosphere is constantly regulated.

Nutrient transfer and transport occur in cyclical pathways as a result of interrelated interactions between living and nonliving components in the biosphere.

Sun is the main source of life for all living organisms in the biosphere. Green plants gather life-sustaining energy with the help of solar energy. Later it spread to all living communities in the biosphere. Biodiversity is the main characteristic of the biosphere. Each species in the biosphere develops in specific habitats through interbreeding, reproduction, distribution, etc (2) & (4).

Q&A

1. How many levels of the organization are ecologists concerned with?

Five levels of the organization are ecologists concerned. These are organisms, populations, communities, ecosystems, and the biosphere.

2. What is the simplest level of ecological organization?

The organism is the simplest level of ecological organization.

3. What are the levels of ecological organization in order?

Organism, population, community, ecosystem, biome, and biosphere are the levels of ecological organization in order.

4. What are the levels of ecological organization?

The six levels of the ecological organization are Organism, population, community, ecosystem, biome, and biosphere.

5. List the levels of ecological organization from largest to smallest?

Biosphere, biome, ecosystem, community, population, and organism.

6. Which of these levels of ecological organization is most inclusive?

The biosphere is the most inclusive level of ecological organization.

7. Which level of ecological organization is each statement describing?

The ecosystem is what each statement describes.

Written By: Manisha Bharati