Unit 3: Ecosystems Flashcards
What are the four main players in ecosystems?
Abiotic Environments
Primary Producers
Consumers
Decomposers
What do decomposers do?
Transfer chemical elements back to soil water or air
Can be prokaryotic or fungal
Are active at all trophic levels
In trophic structures, a food ____ shows the transfer of food energy through trophic levels.
Chain
What are some limits on food chains?
Energetic Hypothesis: 10% of energy is transferred between trophic levels due to inefficiencies
Dynamic Stability Hypothesis: long food chains are less stable than short ones
If approximately 1,000,000 J of sunlight energy is released, approximately how much of that energy (in J) is available for the tertiary consumer?
10 J
Gross Primary Production
Amount of light energy to chemical energy by photosynthesis
Net Primary Production
GPP - energy used by primary producers for cellular respiration
If 200 J of energy was eaten by a grasshopper, 100 is released as feces and 67 is used for cellular respiration, how much is passed on?
33 J
What are some limitations to aquatic ecosystems?
Depth of light penetration
Nutrient abundance
Eutrophication
Influx of nitrogen or phosphorus containing fertilizers in freshwater lakes which can cause algal blooms, resulting in an increase in decomposer population and a decline in fish species
What are some limitations to terrestrial ecosystems?
Temperature
Moisture
If plants were removed from the following chain, would it represent bottom-up or top-down control?
Plants –> Herbivores –> Predators
Bottom-up
Bottom-up food chain
Nutrient supply controls population dynamics via effect on producer productivity
Top-down food chain
Top predators control population dynamics via oscillating cascade effect
Compare the difference in decomposition rates for tropical and temperate forests.
Tropical rainforests decompose organic material in a few months - years.
Temperate forests decompose in about four - six years
