Chapter 31 - Ecosystems Flashcards
Look @ food webs
pls
What percent of solar energy arriving at the earth’s surface is converted into chemical energy through photosynthesis?
1%
Primary producers manufacture … of new biological material per year
150 billion metric tons
Define: GPP
Gross Primary Productivity (GPP)
– Rate at which producers convert solar energy
into chemical energy (kcal/m2/yr) / new
biomass (g/m2/yr)
Define: NPP
Net Primary Productivity (NPP)
– Chemical energy from gross primary
productivity minus energy used for metabolism
– 50-90% of gross primary productivity
What do ecosystems vary in? (Very very general)
They vary in productivity and their contributions to earth’s total productivity
What are the 5 limiting factors of primary productivity?
– How much photosynthetic tissue is present – Temperature – Sunlight – Nutrients – Water
Standing crop biomass and NPP of tropical rainforests
450
22.0
Standing crop biomass and NPP of boreal forest
200
8.0
Standing crop biomass and NPP of extreme desert, rock, sand, ice
- 2
0. 03
Standing crop biomass and NPP of swamp and marsh
150
20
Standing crop biomass and NPP of world in freshwater ecosystems
36
3.3
Define: Secondary productivity
Some energy transferred from producers to
consumers is stored in new consumer biomass,
called secondary productivity
What is some energy used for in secondary productivity? (2)
Maintenance and locomotion
What is energy lost as during energy transfers?
Heat
“Thinking in Scale: Different taxa vary in their
contributions to Earth’s productivity rates”
True or false
True
How much energy is converted to biomass when transfered between levels?
5-20%
Pyramids of energy generally have…
Broad bases and narrow tops
In what ecosystems are pyramids of biomass usually inverted?
Aquatic ecosystems
Terrestrial ecosystems have inverted pyramid of biomass.
True or false?
False
What does a general pyramid of numbers look like?
Normal pyramid
How do consumers influence primary productivity?
Through food preferences and by the numbers
Earth is almost a … system with respect to…
closed
matter
What groups do nutrients cycle between? (2)
Abiotic environments and living organisms in biogeochemical cycles
What does water circulate through?
atmosphere, oceans, and
terrestrial and freshwater ecosystems, and back
to oceans
Water … from the oceans and continents and falls as …
Evaporates
Precipitation
What returns excess precipitation from land to oceans?
Runoff and streamflow
What was the carbon cycle created by?
Created by common atmospheric pool of CO2
How are terrestrial and aquatic ecosystem linked
Thrrough the atmospheric pool of CO2
What does respiration do?
It returns CO2 to the atmosphere
What is the largest resivoir of carbon?
Sedimentary rock
What does the nitrogen cycle do?
It moves nitrogen between living organisms and atmospheric nitrogen gas
What organisms make nitrogen available to the food web (2) and through what means? (3)
Bacteria and cyanobacteria
Nitrogen fixation
Ammonification
Nitrification
What does denitrification do?
It returns nitrogen compounds to N2 so it can return to the atmosphere.
What two ecosystems does phosphorous move between in a sedimentary cycle?
Terrestrial and marine
Dissolved phosphates ... out of seawater, forming ... that are eventually uplifted by ...
precipitate
insoluble deposits
tectonic processes
How is phosphorous released from rock
By weathering and erosion
Weathering and erosion of
rock release phosphorus
which is … from soil
and carried to …
leached
oceans
Define: Biota
The species occuring in a specified area
Define: Biomes
The habitats or areas defined by their
biota
Define: Ecozones
Extensive ecological regions
typically consisting of more than one biome
What are biomes and ecozones terms for? (long)
Identifying categories of habitats, often connecting the species to the prevailing climatic and topographic conditions
