Key Concepts
- Ecology
- Biosphere
- Biotic and Abiotic Factor
- Levels of Organization
- Ecosystem
Session: Ecosystem and Ecology
Introduction
We know that all living things depend on other factors, such as living or non-living, for their survival. So, all living things are interdependent. Interdependency is very important for survival. Each and every day, we share our environment with various organisms such as plants, animals, etc. The study of plants and animals, their eating habits, who eats them is called natural history. The area of biology that is formed from natural history is called ecology. Ecology is the study of communication between organisms and their surroundings.
Biosphere
Living organisms are found in air, water, and land. Biosphere is the area of the earth that supports living organisms. Biosphere supports living organisms in a large variety of situations such as various climatic conditions, soils, plants, and animals. We know that living things are affected by physical surroundings, non-living factors and also by other living organisms. Ecologists study how living organisms reproduce and live in all these different situations (physical and biological situations) in the earth’s biosphere. The lithosphere, hydrosphere, and atmosphere are included in the biosphere.
Ecosystem
An ecosystem is defined as a community of living organisms interacting with each other, including their non-living surrounding.
The hierarchy of an ecosystem is organisms, population, community, biome, and biosphere.
Organism: An organism is any living thing.
Population: It is a group of organisms belonging to the same species. The same species live in the same area at the same time. For example: People living in the same area, zebras living in Savanna in Africa. Savanna is a mixed grassland and woodland ecosystem.

Fig 1. Zebras in Savanna
Community: It is made up of different populations in the same area at a particular time. For example: Various types of flowers grow in the same area. This is called the community of flowers.

Fig 2. Community of flowers
The relationship between different populations and their surrounding atmosphere develops an ecosystem. An ecosystem is made up of different communities in the same population with the community of abiotic factors (non-living things).
Biome: It is the community of plants and animals that occur naturally in an area and generally share common features of that area.
Biosphere is the region that supports living things.

Fig 3. Levels of organization
An ecosystem consists of biotic and abiotic factors.
- Biotic factors: Living organisms make biotic factor. For example: Plants and animals.
- Abiotic factors: Non-living things make abiotic factor. For example: Soil, air, water, sunlight, wind, etc.

Fig 4. Ecosystem and Ecology
The word ecosystem was first used by A.G. Tansley in 1935. He reduced the big word ‘ecological system’ to the ecosystem. According to Tansley, nature work as one system and in that system, organisms and other communities are influenced by many abiotic factors.
Types of ecosystem
On the basis of habitat, an ecosystem is divided into two groups; terrestrial ecosystem and aquatic ecosystem.

Fig 5. Classification of ecosystem
Terrestrial ecosystem: These are located on land. For example: Fields, rotting logs, yards, meadows, volcanoes, garden plots.
Aquatic ecosystem: These occur in freshwater and saltwater. Freshwater ecosystem consists of ponds, lakes, and streams. Saltwater ecosystem consists of wetland, estuaries, and marine ecosystem.
Estuaries: It is an enclosed body where freshwater lakes, ponds, and streams meet saltwater from the ocean.
Organisms in ecosystem
A dog living in a grassland makes its home in a kennel, whereas some species of birds make their nests on the trees. They make their homes in these areas because they find food, avoid enemies, and reproduce. A habitat is a place where an organism lives. For example: For human beings, the house is their habitat. Habitats can change due to natural and human-made causes.

Fig 6. Habitat House
Ecology
Ecology is the study of interactions between organisms and their surroundings. Scientists gain information by observing organisms in their natural surroundings.
Summary
- All living things depend on other factors for their survival.
- Living organisms are found in air, water, and land.
- Biosphere is the area of the earth that supports living organisms.
- The components of an ecosystem are organisms, population, and community.
- The relationship between different populations and their surrounding atmosphere
develops an ecosystem. - An ecosystem consists of biotic and abiotic factors.
- The word ecosystem was first used by A.G. Tansley in 1935.
- On the basis of habitat, an ecosystem is divided into two groups; terrestrial ecosystem
and aquatic ecosystem. - Ecology is the study of interactions between organisms and their surroundings.
Related topics
Character Displacement : Abstract and History
Introduction: CHARACTER DISPLACEMENT Abstract Introduction Character displacement favors the evolution of novel resource use or reproductive traits, drives divergence between sympatric and allopatric conspecific populations, and both initiate and finalize the process of speciation. Despite the significance of character displacement, research has been largely focused on whether it occurs or not. However, it is needed […]
Read More >>Process of Natural Selection and Evolution
Key Concepts • Natural selection • Variation • Adaptation • Process of natural selection Introduction Natural selection is one of the important mechanisms of evolutionary change and is the process responsible for the evolution of adaptive features in various species. It is a force that causes groups of organisms to change over time and it […]
Read More >>Release of Energy – Detailed Explanation
Introduction Release of Energy Food web organisms transmit energy from producers to consumers. Organisms require energy to complete complicated activities. The great majority of energy in food webs comes from the Sun and is turned (processed) into chemical energy via the photosynthesis process in plants. When molecules are broken down during respiration in plants, a […]
Read More >>Formation of Food Molecule – Types, Importance
Key Concepts Food Molecules Carbohydrates Fats/Lipids Proteins Process of photosynthesis Importance of photosynthesis Step involved in photosynthesis Introduction Food Molecules Food is made up of many biological molecules that provide us with energy and include chemicals that we require to develop and repair ourselves and assist our cells to work in our bodies. Carbohydrates and […]
Read More >>Other topics

Comments: