Feeding Relationships in an Ecosystem

There are two types of food relationship in an Ecosystem namely: Food Chains and Food webs.

1. Food Chain

A food chain is a simple feeding relationship showing how energy passes from one organism to another.
General pattern of a food chain:
Producer → Primary Consumer → Secondary Consumer → Tertiary Consumer

Example:
• Cabbage → Butterfly → Lizard → Snake

Key Points
• Begins with a producer. Eg plants
• Shows one feeding pathway that is each organism has only one source of food and if a consumer organism is killed; the food chain will be destroyed or disrupted.
• Energy flows in one direction originates from the sun
• Usually contains 4–6 organisms.

Trophic Levels
• A trophic level is the feeding position occupied by an organism.
• Using the pattern Producer , Primary consumer ,Secondary consumer , Tertiary consumer
• The 10% Rule meaning Only about 10% of the energy at one trophic level is transferred to the next. Around 90% is lost as heat, movement, respiration and waste.

2. Food Web
A food web is a network of interconnected food chains where energy and matter are transferred from green plants through a series of animals.

Advantages

• More stable than a food chain.
• Organisms have alternative food sources.
• Less likely to collapse if one organism disappears.