Community-level systems Flashcards
What is an ecosystem
Community + habitat
What abiotic factors affect communities
Light intensity (photosynthesis)
Temperature (metabolism (enzymes))
Moisture level
Soil pH
What do plants need to survive
Shelter
Breeding partners
Food
Water
Space
What do plants need to survive
Co2
Water
Light
Minerals
Space
What are the three main ecological relationships
Predation - predator and prey, directly affected populations
Mutualism - both benefit
Parasitism - parasite feeds off host
How do you calculate biomass and what is a biomass pyramid
Number of organisms * average mass
A diagram showing the biomass at each trophic level
How do you calculate efficiency of biomass transfer
100 * (bm available after transfer)/(bm available before)
How is biomass lost between trophic levels
Not entirely consumed , eg bones
Some used in respiration
Egestion , eg hair and teeth
Waste , eg urine
Summarise the water cycle
Transpiration and evaporation, condensate, cool, precipitate (repeated)
Explain briefly the nitrogen cycle
Ammonia become nitrated (nitrifying bacteria), which can then be absorbed by plants or released (denitrifying bacteria) later absorbed by nitrogen-fixing bacteria. These become plant proteins, are later eaten, excreted/ decay, becoming ammonia (decomposers)
Explain briefly the carbon cycle
Into atmosphere:
Burning fossil fuels, respiration
Out:
Photosynthesis -> decomposition -> fossil fuels
What factors affect the rate of decomposition
-Warm temperatures
-Moisture
-Oxygen
What is the difference between a decomposer and a detritivore
DC - microorganisms, decay dead organic material at microscopic level
DV - small animals, give DC larger surface area
How do decomposers release nutrients
Release enzymes which break down matter making it soluble for them to absorb
