Ecotsystem Ecology Flashcards
Primary producers allow energy to be….
Available to all species in the ecosystem
Why are plants measured by dry mass
Because once you cut the leaf the water is lost
Primary production
The conversion of inorganic material into organic material
Gross primary production
Total primary production
The rate at which energy is captured and assimilated by producers in a given area
GPP=PP
Net primary production
NPP=GPP-R
R=respiration
PP available to consumers
The rate at which energy is assimilated by producers and converted into producer biomass in a given area
Standing crop
The bodies/biomass of the living organisms within a unit of area
Biomass
Mass of organisms per unit area of ground or volume of water
Initial mass and final mass of leaves left in light and in dark
More initial mass in dark (carbon dioxide lost)
More final mass in light (carbons dioxide used to make photosynthetic products)
What percent of NPP is the total solar energy
1% of solar input becomes biomass
PP is affected by what factors
-geographic range
-water
-nutrient levels
-temperature
-photosynthetic efficiency
-vegetative cover
-length of growing season
Lieberg law of minimum
The rate of any biological process is limited by the factor in the least amount relative to requirements for that process
Where is the greatest rate of PP in oceans
Coastlines
-upwelling of nutrients
What does adding nitrate and phosphate do to primary production of algae
Increases it but varies by site
Helps a bit but not much (not as limiting)
The more nitrogen you add, phosphorous becomes _____
The more phosphorous you add, nitrogen becomes _____
Limiting factor
Limiting factor
How limiting are nitrogen and phosphorus in terrestrial, freshwater and marine ecosystems
-N and P are limited equally
-same as above
-N is more limiting
What ecosystem has the most primary production
Swamps and marshes
Two laws of thermodynamics
-total amount of energy in the universe is constant (can’t be created or destroyed, only transferred)
-heat energy moves from warmer body to colder one
_____ increases over time in a closed system
Entropy (amount of disorder)
Trophic level
Position on the food web determines by the number of transfers of energy from primary producers
__________ limit the number of trophic levels in an ecosystem
Energy losses
As energy is transferred from one trophic level to another, there are losses:
-Incomplete consumption
-incomplete assimilation
-respiration by consumers
-heat production
Terrestrial vs aquatic ecosystems biomass
Terrestrials have lots of producers and smaller tertiary consumers
Aquatic has smaller amount of producers that feed a massive biomass of consumers
Terrestrial PP is limited by
Temperature and moisture
Aquatic PP is limited by
Nutrient availability
Green food web
A food web focussed on how the producers obtain energy from photosynthesis and how this energy moves up the food web when producers are consumed.
Brown food web
Focussed on how scavengers, Derrick red and decomposers obtain energy from dead organic matter and how this energy moves up the food web when they are consumed
Egested energy
Assimilated energy
The portion of consumed energy that is excreted or regurgitated
The portion of consumed energy digested and absorbed
Respired energy
The portion of consumed energy used for respiration
Net secondary productivity
The rate of consumer biomass accumulation in a given area
Increase in_____ leads to an increase in NPP
Annual temperature
Consumption efficiency
The percentage of energy or biomass in a trophic level that is consumed by the next higher trophic level
CE=Consumed energy/net production of energy of the next lower trophic level
Assimilation efficiency
The percentage of consumed energy that is assimilated
AE=assimilated energy/consumed energy
Net production efficiency
The percentage of assimilated energy that is used for growth and reproduction
Net production efficiency=net production energy/assimilated energy
Ecological efficiency or food chain efficiency
Net production energy of a trophic level/net production energy of the next lower trophic level
The percentage of net production from one trophic level compared to the next lower trophic level
Which ecosystem typically has more trophic levels
Aquatic
Residence time
The length of time that energy remains in a given trophic level
Ecological stoichiometry
The study of the balance of nutrients in ecological interactions, such as between a herbivore and a plant
