2.2 communities and ecosystems Flashcards
ecology
- study of ecosystems
- major input/output is energy
inputs
majority of ecosystems gain input of energy as light from the sun via photosynthesis
- carbon dioxide + water → glucose + oxygen
outputs - heat energy
- living organisms can’t convert heat to other sources of energy –> lost bc of second law of thermodynamics
- energy leaves areas of high concentration (living things) and moves towards a more equal concentration (out into space)
- means that energy trapped by photosynthesis is lost at every trophic level; energy flows through ecosystems, not recycled
trophic level
describes the role an organism plays in food chain
trophic level one
primary producer: organism that nourishes itself using an inorganic form of energy (sunlight/chemical compounds)
- e.g: plants, chemosynthetic bacteria
trophic level two
primary consumer: animal that feeds off primary producers
- e.g: deer, cow
trophic level three
secondary consumer: animal that feeds off primary consumer
- e.g: lion, wolf, humans
decomposers
consume dead and non-living material
- e.g: worms, maggots
pyramids of energy
represent the energy that moves between trophic levels
productivity
- conversion of energy into biomass over a period of time
- enables ecologists to compare the efficiency of photosynthesis between different biomes
GPP - gross productivity
amount of energy that enters a trophic level
NPP
- is GPP - R
- the amount of energy left over for growth and reproduction and available for consumers
GSP - gross secondary productivity
- the total energy/biomass taken by consumers
- equation: food eaten - ‘fecal loss’
NSP - net secondary production
equation: GSP - R
MSY - maximum sustainable yield
max amount that can be taken (yield)
