Lecture 25: Ecosystem Ecology Flashcards
Food web
who eats who in the ecosystem; energy transfers
what represents energy transfer?
arrows
what is the first level of the trophic structure?
primary producers/autotrophs; ex: trees, plants
what is the second level of the trophic structure?
primary consumers/herbivores; ex: ant, bees
what is the third level of the trophic structure?
secondary consumers; ex: rat, frog
what is the fourth level of the trophic structure?
tertiary consumers; ex: snake, owl
what is the fifth level of the trophic structure?
quanterriary consumers; ex: eagle
does energy transfer increase or decrease as you go up the trophic structure?
decrease
primary production
process by which organisms create organic compounds from inorganic carbon
inefficiency of energy transfer
limits how many tertiary consumers
trophic efficiency
efficiency of the transfer between trophic structures
energetic hypothesis
idea that the inefficiency of teh transfers limits the higher level species
What are the three biogeochemical cycles?
- carbon cycle 2. nitrogen cycle 3. phosphorus cycle
Carbon cycle
carbon-fixation: process that gets carbon from the inorganic form into living systems
nitrogen cycle
nitrogen fixation: only microbes can do; gets N from nitrogen gas into something useful
phosphorus cycle
P gets locked in physical form to a more dissolved water form–>then living things can pick it up
Benthic Zone
region at bottom of a body of water
stream/river
moving fresh water
pelagic zone
open ocean where there are wind driven currents
lakes
fresh water that doesn’t move
oligotrophic
high oxygen and low organic nutrient content
eutrophic lake
oxygen is depleted and a lot of organic sedimentation
