Ecosystem

Summary

An ecosystem is a functional system in which organisms interact with one another and with abiotic surroundings.

Core idea

Understand the system

An ecosystem is a functional system in which organisms interact with one another and with abiotic surroundings.

Why and how it happens

Causes and context

An ecosystem is a functional system in which organisms interact with one another and with abiotic surroundings. The governing relationship is: Energy flows mainly from sunlight through trophic levels, while nutrients cycle between biotic and abiotic components.

How it works

Energy flows mainly from sunlight through trophic levels, while nutrients cycle between biotic and abiotic components.

Key facts

• Producers capture energy; consumers transfer it; decomposers recycle matter.
• Food webs are more realistic than single food chains.
• Ecosystem boundaries can be open and defined at different scales.

Important terms

• biotic
• abiotic
• trophic level
• food web
• decomposer

Examples and case studies

• A mangrove ecosystem links salinity, sediment, plants, fish, microbes and human livelihoods.

Causes and components

• Key components: biotic, abiotic, trophic level.
• Energy flows mainly from sunlight through trophic levels, while nutrients cycle between biotic and abiotic components.

Effects and significance

• Food webs are more realistic than single food chains.
• Ecosystem boundaries can be open and defined at different scales.
• Application: A mangrove ecosystem links salinity, sediment, plants, fish, microbes and human livelihoods.

Geography connection

A mangrove ecosystem links salinity, sediment, plants, fish, microbes and human livelihoods. This illustrates how ecosystem varies by location, scale or environmental context.

Bangladesh connection

The Sundarbans, haor wetlands, floodplains and coastal estuaries are major Bangladesh ecosystem examples.

BCS preliminary facts

• Producers capture energy; consumers transfer it; decomposers recycle matter.
• Food webs are more realistic than single food chains.
• Ecosystem boundaries can be open and defined at different scales.

BCS written analysis

Build an analytical answer

• An ecosystem is a functional system in which organisms interact with one another and with abiotic surroundings.
• Energy flows mainly from sunlight through trophic levels, while nutrients cycle between biotic and abiotic components. Use a mangrove ecosystem links salinity, sediment, plants, fish, microbes and human livelihoods. as a named application in a comparative answer.

Common misconceptions

• Energy flows one way while nutrients cycle.
• An ecosystem is not only its organisms; abiotic conditions are essential.

Quick revision

• Ecosystem
• Producers capture energy; consumers transfer it; decomposers recycle matter.
• Food webs are more realistic than single food chains.
• biotic / abiotic
• Definition → process → spatial example