CH55 Flashcards
Why would a species X be absent from an area?
- Area not accessible or insufficient time to leave area
- If not, abiotic factors such as salinity, temperature, moisture
- If not, biotic factors such a predation, herbivory, competition, pathogens
What are an ecosystem’s emergent properties?
Energy flow and chemical cycling
Define
Stock
Amount of some resource. Measured at a fixed point in time, with units
Define
Flow
A measure of input or output into/from a stock, in units/time
Define
Turnover time
Time it would take to replenish the whole stock
What is the first law of thermodynamics?
Energy cannot be created/destroyed, but only transformed
What is the second law of thermodynamics?
Every energy exchange increases entropy and energy conversions are inefficient
Who are the primary producers?
Photoautotrophs, who fix carbon and nutrients into new material. Support all the layers above
Who are the primary consumers?
Herbivores
Who are the secondary consumers?
The carnivores who eat herbivoes
Who are the tertiary consumers?
The carnivores who eat the secondary consumers
Eaten by quaternary consumers
Describe
Detritivores
- Also called decomposers
- They are linked to every trophic level
- Consumers of non-living material, transform organic matter into organic compounds usable by primary producers
Define
Primary production
The amount of light energy converted to chemical energy (organic compounds) by autotrophs during a given time period
Define
Net primary production
- The amount of plant biomass available to consumers
- Gross primary production - energy for autotrophic respiration
What are the limitations of terrestrial ecosystems?
Nutrient limitation (ammonium and phosphate), as a consequence of latitude
