Ecosystem

An ecosystem is defined as the community of plants and animals living together in harmony and interacting with their physical environment.  In other words, ecosystem can also be defined as the interaction or relationship between organisms (plants and animals) and their physical environment.

Components of Ecosystem

The ecosystem is made up of two major components.  These are:

1. Abiotic component: This is the non-living component of the ecosystem. It includes factors or elements like soil, water gases and sunlight.  It represents the physical environment
2. Biotic component: This is the living component of the ecosystem.  It represents the biological component which includes plants and animals.  However, the biotic component can be grouped into three sub-classes which are:

• Autotrophs: They are also called These are green plants which can manufacture their own food from simple inorganic substances through the process of photosynthesis.  These are organism which cannot manufacture their own food but depend directly or indirectly on plants for their own food.  Examples are man, parasites and saprophytes.
• Decomposers: These are micro-organisms that decompose dead organic matter in order to release nutrients required by producers to prepare their food, e.g. fungi and bacteria.

In summary, the components of an ecosystem can also be grouped into the following:

1. Land (soil)
2. Water (lake and oceans)

• Plants

1. Animals
2. Drainage (e.g. river)
3. Climate (Atmosphere)

Interdependence Within Ecosystem

The relationship between the components of the ecosystem can best be described as interdependent.  In other words, all the components in an ecosystem depend on one another and they cannot exist in isolation.  Again, a state of interdependence within the ecosystem is best achieved where the component are undisturbed.

Discussion on interdependence within and between the biotic and Abiotic components are grouped into three classes which are:

1. Interdependence within Abiotic Component
2. Rocks weather to form soil
3. Rocks also change to mineral like coal, petroleum and other soil nutrients

• Water from the seas and oceans evaporate for cloud and rain

1. Soil formation is influenced by climatic factors like rainfall
2. Rainfall and temperature are required for chemical weathering of parent rocks
3. The drainage (rivers, seas and oceans) provides water.
4. Interdependence within Biotic Component
5. Animals depend on plants for their own food
6. The decomposition of dead animals provides manure for plants

• The activities of micro-organism in the soil also provide growth for plants

1. Animals during respiration provide carbon dioxide for plants to carry out photosynthesis
2. Plants also provide oxygen for animals during photosynthesis which they use for respiration
3. Primary consumers (herbivores) in turn are fed upon by secondary consumers (carnivores)

• All consumers and autotrophs are in turn broken down by bacteria during decomposition
• Interdependence Between the Biotic and Abiotic Components

1. The water, carbon dioxide and nitrogen cycles provide energy and nutrients for plants growth
2. Autotrophs depend on soil for support and nutrients

• Autotrophs convert sunlight, energy, water and carbon dioxide during photosynthesis to produce food.

1. All human activities are mainly carried out on the soil
2. Soil, air and water provide habitat for living organisms
3. Oxygen and carbon dioxide are made constant through respiration and photosynthesis by living organisms.

• Food produced form the sue of sunlight, water and carbon dioxide are consumed by primary consumers
• Primary consumers in turn are fed upon by secondary consumers

1. Tertiary, secondary, primary and autotrophs are in turn broken down to form soil by bacteria during decomposition.

Summary of Interdependence between the Abiotic and Biotic Components

1. Plants depend on soil for support and nutrients
2. All human activities are mainly carried out in the land.

• Soil, air, water provide habitat for living organisms

1. Food produced from the use of sunlight, water and other gases are consumed by animals
2. Some gases such as oxygen carbon-dioxide are returned to nature through respiration and photosynthesis.

Dead plants and animals are broken down to form soil by bacteria during decomposition