Communities to Ecosystems Flashcards
How is an ecosystem different from a community?
Ecosystems include abiotic factors
What is the difference between a food web and a food chain?
A food chain is the flow of energy from prey to predator, food webs are side by side interconnected food chains
What can food webs describe?
Community interactions, competition, predation, parasitism, mutualism based on food acquisition
What are the 3 species levels in a food web?
Basal species: don’t feed on others and are fed upon
Intermediate species: feed on other species and are fed upon
Top predators: feed on others but are generally not fed upon
What is a guild?
A group of organisms that make their living in a similar way
What are competitive asymmetries?
Strong competitors create competitive hierarchies
What are keystone species?
Species with a disproportionate effect on the community relative to its abundance
Why are highly numerous species that the ecosystem depends upon not keystone species?
Their impact comes from their numbers
What happens when a keystone species is removed?
Trophic cascades, loss of diversity
What is an ecosystem engineer?
A species whose activities create or maintain new habitat (beavers)
In what order does energy proceed through the trophic levels?
Sun -> plants -> consumers -> decomposers
In what order do nutrients proceed through the trophic levels?
Inorganic nutrient pool -> producers -> consumers -> decomposers -> back to nutrient pool
How much energy is passed on to each trophic level?
10%
How is the end result energy and nutrients different once it reaches decomposers?
Energy flows and gets released as heat, nutrients get recycled
Which nutrient limits primary production in aquatic systems and in terrestrial systems?
Phosphorus in aquatic, nitrogen in terrestrial
