What is an Ecosystem?

Ecosystem = All living (biotic) and non-living (abiotic) things in an area that interact with each other.


Examples: pond, forest, desert, garden, crop field, grassland

Key components:

  • Biotic components
  • Abiotic components

Biotic & Abiotic Components

Every ecosystem has two main types of components that work together.

Important points:

  • Biotic (living)
  • Abiotic (non-living)
  • Balance is important

Food Chain & Food Web

Food chain shows the transfer of energy from one organism to another.

Example: Grass → Grasshopper → Frog → Snake

Key points:

  • Food Chain
  • Food Web
  • Energy transfer

Producers (Autotrophs)

Producers make their own food using sunlight (photosynthesis).

Examples: green plants, algae

Key points:

  • Photosynthesis
  • Base of energy flow
  • Chlorophyll

Consumers (Heterotrophs)

Consumers cannot make their own food and depend on others.

Types:

  • Herbivores
  • Carnivores
  • Omnivores

Decomposers

Decomposers break down dead plants and animals and return nutrients to soil.

Examples: bacteria, fungi, earthworms

Key role:

  • Decomposition
  • Nutrient recycling
  • Cleaners of nature

Energy Flow in Ecosystem

Energy flows in one direction only: from the Sun through producers to consumers and finally to decomposers.

Important rules:

  • Only about 10% of energy is transferred to the next trophic level (10% law)
  • Energy flow is unidirectional – it never goes backwards
  • The Sun is the ultimate source of energy for all ecosystems

Click any dotted line below to see how energy flows and animates!

Sun
Plants
Primary
Consumers
Secondary
Consumers
Decomposers

Click any arrow above

Watch how energy moves through the ecosystem step by step!

Only ~10% of energy passes to the next level — most is lost as heat!

Ecosystem Challenge



× Zoomed diagram