3-Ecosystem Flashcards
ECOSYSTEM
a biotic community and its abiotic environment
- can be small or large
-
ecosystem ecologists ask:
- how does energy flow through a system
- how do nutrients cycle between the abiotic and biotic components of a system?
PRODUCERS
- aka autotrophs
- obtain their energy by using photosynthesis to convert solar energy to chemical energy
CONSUMERS
- aka heterotrophs
- obtain energy by eating other organisms
what are the two types of consumers that eat dead organic material
-
detritvores—ingest dead organic material, break down material internally
- earthworms, slugs
- decomposers—break down dead organic material, then absorb nutrients
FOOD CHAIN
the linear transfer of food energy from one trophic level to the next trophic level
food web
food web—series of interlocked food chains that allow for the possibility of omnivores (consumers of multiple trophic levels)
primary productivity
- rate of conversation from solar energy to chemical energy by producers
- biomass/area/time
- energy/area/time
gross primary productivity (GPP)
absolute rate of primary productivity
net primary productivity (NPP)
rate of primary productivity after accounting for cellular respiration
ten percent rule
approximately 10% of the chemical energy at one trophic level is transferred to the next trophic level
why is energy lost between trophic levels?
- not all of the organisms at one trophic level are consumed by organisms at the next trophic level
- ~90% of producer biomass is consumed by detritivores and decomposers
- not all food eaten is completely digested
- energy is lost as heat (by-product of metabolism)
- energy used for hunting
- this creates a biomass pyramid
- it takes MAAANY primary producers to support only a few teritary consumers
what are the nutrients that are chemicals needed for growth and maintenance for life
- N (nitrogen)
- P (Phosphorus)
- C (Carbon)
- O (Oxygen)
- Fe (iron)
nutrients do not come from outside the earth and instead have to be recycled
pools
where nutrients are stored
fluxes
movement in and out of pools
Carbon
- essential nutrient that is required for growth and reproduction
- basic building block of organic molecules
- mainly stored in oceans and atmostphere
- soils, living organisms, and fossil fuels are also important pools of C