APES Unit 1 (Module 7 - Trophic levels, energy flow/10% rule, food chains/webs)

consumers

aka heterotrophs, incapable of photosynthesis and must obtain energy by consuming other organisms

primary consumers

consumers that eat producers are primary consumers, or herbivores 

carnivores

 consumers that eat other consumers

secondary consumers

carnivores that eat primary consumers

tertiary consumers

carnivores that eat secondary consumers 

trophic levels

successive levels of organisms consuming one another

food chain

sequence of consumption from producers through tertiary consumers

scavengers

organisms that consume dead animals

detritivores

organisms that break down dead tissues and waste products into smaller products

decomposers

fungi and bacteria that complete the breakdown process by converting organic matter into small elements and molecules that can be recycled back into the ecosystem

ecological efficiency

 proportion of consumed energy that can be passed from a trophic level to another

10% rule

total biomass available at a given trophic level, only about 10% can be converted into energy at the next highest trophic level

trophic pyramid

distribution of biomass, numbers, or energy among trophic levels 

food web

model of how energy and matter move through two or more interconnected food chains

positive fluctuations

in the abundance of one species, causes positive feedback loops on some species 

• Can have a direct positive effect on a species, leading to an indirect positive/negative effect for another 

negative fluctuations

in the abundance of a species, causes negative feedback loops on some species

• Can have a direct negative effect on a species, leading to an indirect positive/negative effect for another