IB ESS Topic 2.2: Energy Flow

These flashcards cover key concepts related to energy flow in ecosystems, including trophic levels, energy transfer, and productivity metrics.

Trophic Level

A feeding level in a food chain.

Producers

Organisms, such as plants and algae, that convert sunlight into chemical energy through photosynthesis.

Primary Consumers

Herbivores that eat producers.

Secondary Consumers

Carnivores that eat primary consumers.

Tertiary Consumers

Top predators in a food chain.

Decomposers

Organisms that break down dead organic matter and return nutrients to the system.

Food Chain

A simple, linear pathway of energy transfer in an ecosystem.

Food Web

A complex network of interconnected food chains, representing a more realistic depiction of energy flow.

Energy Pyramid

A representation of energy decrease at each trophic level, always upright because energy is lost as heat.

10% Rule

Only about 10% of energy is passed to the next trophic level; around 90% is lost as heat, movement, and waste.

Gross Primary Productivity (GPP)

Total energy captured by producers.

Net Primary Productivity (NPP)

Energy available to consumers after accounting for respiration; calculated as NPP = GPP - R.

Respiration (R)

The process by which organisms convert energy for use, producing heat and utilizing energy.

Ecosystem Efficiency

The measure of how much energy enters an ecosystem and is converted by producers into biomass.

Biomass Distribution

The distribution of biomass, indicating how energy is allocated among different trophic levels in an ecosystem.