Ecosystem and Ecology – Definition, Hierarchy & Types

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.