Ecosystem Ecology Flashcards
ecosystem
all the biotic and abiotic components of a region
primary producer
autotroph - organism that can synthesize its own food from inorganic sources (plants, algae, phytoplankton)
GPP
gross primary production - total carbon fixed by primary producers
GPP uses how much solar energy
about 0.8%
NPP
net primary productivity - energy used for growth and reproduction
distribution of GPP
45% to NPP 55% to cellular resipration
NPP=
GPP - respiration
NPP represents the amount of energy
available to other organisms in ecosystem
consumers
eat living organisms
decomposers
detritivores - obtain energy by feeding on the remaining other organisms
organisms that consume energy from the same type of sources occu0py the same
trophic level
brown food webs
rely more on dead material - most of biomass is consumed by decomposers
forests are what type of food web
brown
marine ecosystems are what type of food web
green
biomass declines at each
higher trophic level (10% transfer, but can vary)
where does energy go
maintenance cost of living, growth and reproduction (into mass), excretion (not all energy is obtained from food source)
what type of energy is carried to next trophic level
energy that goes into growth and reproduction
why are sea otters keystone species
great impact on abundance of other species relative to abundance of its own species
trophic cascade
when changes in top-down control affect populations 2-3 links away in food web
how did wolves change the rivers
decrease in lower level consumers, increase in vegetation, soil stabilization, less erosion
