Ecosystems, Energy Flow, and Trophic Levels

Vocabulary flashcards covering ecosystem types, energy flow, trophic levels, autotrophs, heterotrophs, and energy pyramids based on the lecture notes.

Ecosystem

An ecological unit consisting of biotic components coexisting with abiotic components.

Closed System

An ecosystem or system where only energy is able to pass in and out.

Open System

An ecosystem or system where both energy and matter are able to pass in and out.

Sunlight

The principal source of energy that sustains most ecosystems, with exceptions such as caves and below light penetration levels in oceans.

Food Chain

A linear sequence of organisms, each feeding on the previous one.

Food Web

A complex network of interconnected food chains, representing all feeding relationships in a community.

Decomposers

Organisms that break down dead organic matter (including faeces, dead parts, and dead whole organisms), releasing energy and recycling nutrients back into the ecosystem.

Autotroph

An organism that uses external energy sources to synthesize carbon compounds.

Carbon Fixation

The conversion of inorganic carbon such as $CO_2$ into organic compounds like glucose ($C_6H_{12}O_6$).

Chemoautotrophs

Organisms that release energy by oxidising inorganic substances and use this energy to convert $CO_2$ into food for habitats that live without sunlight.

Heterotrophs

Organisms that obtain energy and carbon by consuming other organisms or organic matter.

Carbon Sink

An ecosystem that absorbs more carbon than it releases.

Carbon Source

An ecosystem that releases more carbon than it absorbs.

Energy Pyramid

A graphical representation showing the flow of energy across trophic levels, lost energy as heat, and nutrient recycling, starting with producers at $1001\%$ energy down to apex predators at $0.011\%$ energy.

Primary Producers

Organisms at the base of the energy pyramid that convert sunlight into chemical energy ($100\%$ energy level), such as crop plants, trees, grass, flowering plants, corn, lavenders, and mangoes.

Primary Consumers

Organisms that eat primary producers ($10\%$ energy level), such as grasshoppers, bees, ants, butterflies, and fruit flies.

Secondary Consumers

Organisms that feed on primary consumers ($1\%$ energy level), such as rats, sparrows, frogs, dragonflies, and thrushes.

Tertiary Consumers

Carnivorous organisms at the fourth trophic level ($0.1\%$ energy level), such as snakes and owls.

Apex Predators

Top predators occupying the highest level of the energy pyramid ($0.01\%$ energy level), represented by hawks.