STRUCTURE AND FUNCTIONOF AN

ECOSYSTEM

BY

ABHISHEK GARG

ECOSYSTEM•An ecosystem is a community of

living organisms in conjunction with the nonliving components of their environment, interacting as a system

• Ecosystem consists of two Words :

Ecosystem

EcoEnvironme

nt

System Interaction

• According to E.P.Odum, an American ecologist, the ecosystem is the basic functional unit of organism and their environment interacting with each other and with their own components.

• e.g. Grassland, Forest, Aquarium, Pond, Lake, River and Ocean.

Ecosystem - Definition

Grassland Ecosystem

Forest Ecosystem Ocean Ecosystem

Structure of Ecosystem

Ecosystem

Abioticnon-living

Eg. soil, water, light,

inorganic nutrients

and weather

Bioticliving

Eg. producers

and consumers

BIOTIC LIVINGBiotic Resources are based on living organisms. These are obtained from the biosphere. E.g Consumers,Producers and Decomposers.

Consumers: Producers are any kind of green plant. Green plants make their food by taking sunlight and using the energy to make sugar.

Producers :Consumers have to feed on producers or other consumers to survive. Deer are herbivores, which means that they only eat plants (Producers). Bears are another example of consumers.

Decomposers: Decomposers are the garbage men of the animal kingdom; they take all the dead animals and plants (consumers and decomposers) and break them down into their nutrient components so that plants can use them to make more food.

ABIOTIC COMPONENT• In Biology and Ecology abiotic components or abiotic

factors are those non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems.

• These are obtained from the lithosphere. E.g : soil,  temperature, humidity.

• Habitat is considered as abiotic componenet,

• A Habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant, or other type of organism

The components of the ecosystem are seen to function as a unit when we consider the following aspects:

•Productivity

•Decomposition

•Energy flow

•Nutrient cycling

Function of Ecosystem

• Productivity - The rate of biomass production is called productivity.

• Gross primary productivity - The rate of production of organic matter during photosynthesis is called gross primary productivity.

Gross PP (GPP) = total energy fixed

Secondary productivity – The rate of formation of new organic matter by consumers is called secondary productivity .

PRODUCTIVITY

• The breakdown of complex organic matter into inorganic substances like carbon dioxide, water and nutrients and the process is called decomposition.

DECOMPOSITION

Steps in decomposition

Fragmentation

Leaching

Catabolism

Humification

Mineralization

• The flow of energy is one way direction from producer to consumers, and ends in decomposition process.

•However, a part of the energy is lost as heat and agrees with the phenomenon of second law of Thermodynamics.

ENERGY FLOW

NUTRIENT CYCLE

• A nutrient cycle (or ecological recycling) is the movement and exchange of organic and inorganic matter back into the production of living matter.

• The process is regulated by food web pathways that decompose matter into mineral nutrients.

• Nutrient cycles occur within ecosystems.

NUTRIENT CYCLE