Levels of Organisation – Levels and Types of Ecosystem

Levels of Organisation 

Introduction

We know that all living things depend on other living or non-living factors for their survival. Thus, all living things are interdependent. Interdependency is very important for survival. Every day we share our environment with various organisms such as plants, animals, etc. The study of plants and animals, and their interaction with the surroundings, is called natural history. The area of biology formed from natural history is called ecology. Ecology is the study of communication between organisms and their surroundings.  

Levels of Organisation in Ecosystem

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. 

Organism: It is the lowest level of organization. An organism is any living thing. For example, one orange color fish in Fig. No.1 is an organism.  

Population: It is a group of organisms that belong to the same species and live in the same area at the same time. For example, a group of orange color fish is a population (Fig. No. 1). Members of the population may struggle for food, shelter, mate, and other resources. When the supply of resources is less, the competition among population increases. Certain species have adaptations with the environment that reduces the chances of competition in population. For example, in the life cycle of a frog, the young tadpole and adult frog have different food requirements. Tadpole eats algae whereas adult frogs eats insects. Hence the competition for food is not seen at this stage.

Community:  

Generally, species do not live alone. Every population shares its surroundings with other population. The combination of various populations results in the formation of biological community. Changes in one community may lead to changes in other communities too. For example, if there is a slight increase in the number of snakes within a community, then the number of rats will gradually decrease.  

Some extreme changes can also be seen in a community. For example, if the population of one organism grows faster, then it may threaten the survival of other populations. In forest community, there are many populations, and they depend on each other for food. Such as birds eat insects, squirrels eat nuts, fungi grow on dead and decaying matter of leaves and stem. These populations depend on each other, and they get affected by abiotic factors such as soil, water, temperature, etc. Such a relationship between different populations leads to the development of an ecosystem. 

Ecosystem: 

The relationship between different populations and their surrounding atmosphere develops an ecosystem. An ecosystem comprises of different communities within the same population and the abiotic factors (non-living things) that affect them. The word ecosytem was first used by A.G. Tansley in 1935. He reduced the word ‘ecological system’ to ecosystem.  According to Tansley, nature works as one system and in that system organisms and other communities are influenced by many abiotic factors.  

Ecosystem consists of biotic and abiotic factors.  

Biotic factors: Living organisms make biotic factors. For example, plants, animals, and microorganisms. 

Abiotic factors: Non-living things make abiotic factors. For example, soil, air, water, sunlight, wind, etc. 

Types of ecosystem 

On the basis of habitat, ecosystem is divided into two groups—terrestrial ecosystem and aquatic ecosytem.     

Terrestrial ecosytem: These are located on land. For example: Fields, rotting logs, yard, meadows, volcanoes, garden plot. 

Aquatic ecosystem: These occur in freshwater and saltwater. Freshwater ecosystem consists of ponds, lakes and streams. Salt water ecosystem consists of wetland, estuaries, and marine ecosystem. 

Biome: It is the community of plants and animals that occur naturally in an area, and generally share common features of that area. 

Biosphere: 

Biosphere is the area of 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 surrounding, 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. Lithosphere, hydrosphere, and atmosphere are included in biosphere.