Chapter 42: Ecosystems and Energy

Vocabulary flashcards covering key terms and concepts from Chapter 42 on ecosystems and energy.

first law of thermodynamics

The principle of conservation of energy: energy can be transferred and transformed, but cannot be created or destroyed.

law of conservation of mass

Matter can change form but cannot be created or destroyed; in a closed system total mass remains constant.

primary producers

Autotrophs, usually photosynthetic, that form the trophic level supporting all others in an ecosystem.

primary consumer

An herbivore that eats plants or other autotrophs.

secondary consumer

A carnivore that eats herbivores.

tertiary consumer

A carnivore that eats other carnivores.

decomposer

An organism that absorbs nutrients from nonliving organic material and converts them to inorganic forms; a detritivore.

detritus

Dead organic matter.

primary production

The amount of light energy converted to chemical energy by autotrophs in an ecosystem during a given time period.

gross primary production (GPP)

Total primary production of an ecosystem.

net primary production (NPP)

Gross primary production minus the energy used by producers for respiration.

net ecosystem production (NEP)

Gross primary production minus the energy used by all autotrophs and heterotrophs for respiration.

limiting nutrient

An element that must be added for production to increase in a particular area.

eutrophication

Nutrient enrichment (especially nitrogen and phosphorus) of water bodies, causing excessive growth of algae or cyanobacteria.

secondary production

The amount of chemical energy in consumers’ food converted to their own new biomass during a given time period.

production efficiency

The percentage of energy stored in assimilated food that is not used for respiration or eliminated as waste.

trophic efficiency

The percentage of production transferred from one trophic level to the next, typically ~10%.

biogeochemical cycles

Chemical cycles that involve both biotic and abiotic components of ecosystems.

bioremediation

Use of organisms to detoxify and restore polluted or degraded ecosystems.

biological augmentation

Restoration approach that adds essential materials or organisms to a degraded ecosystem.