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29 Cards in this Set
- Front
- Back
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What is the difference between energy flow and chemical cycling (carbon and nitrogen) in an ecosystem?
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Chemical cycling can be used over and over again from producers all the way down to decomposers, whereas energy must constantly be flowing into an environment (usually from the sun) in order for an ecosystem to survive
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What does the law of conservation of mass say?
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That mass cannot be created or destroyed, just like energy
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T/F: Although nutrients, etc. can be input or output in a system, most come from recycling.
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True
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Detritivores are... (e.g.)
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Decomposers (e.g., prokaryotes and fungi)
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The amount of light energy converted to chemical energy by autotrophs is an ecosystem's...
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Primary production
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Of all the light that finally goes through the atmosphere and reaches plants, how much of the light on the plants actually gets used in creating organic compounds?
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1%
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Total primary production is known as an ecosystem's...
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Gross primary production
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The amount of light energy that is converted to chemical energy per unit of time is...
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Gross primary production
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What two things can be used to limit or promote primary production in an aquatic ecosystem?
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Light and nutrients
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The element that must be added for production to increase is a...
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Limiting nutrient (nitrogen/iron in marine, phosphorus in freshwater ecosystems)
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T/F: Areas of upwelling (where the bottom, nutrient-rich waters constantly cycle with the top) have exceptionally high primary production
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True, which supports the theory that nutrient availability mostly affects primary production, not sunlight
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When nutrients, especially phosphorus and nitrogen, become highly concentrated in water, leading to excess growth of algae or other primary producers, this is known as...
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Eutrophication
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The amount of water transpired by plants and then evaporated in an ecosystem is...
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Actual evapotranspiration
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What two things can be used to limit or promote primary production in terrestrial ecosystem?
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Temperature and moisture (as well as sunlight availability and nutrients, of course)
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The amount of chemical energy in the food of consumers that is converted to their own new biomass (in a time period) is...
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Secondary production
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What is the term for accumulated biomass (not just newly accumulated biomass)?
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Standing crop
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The percentage of production transferred from one trophic level to the next is...
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Trophic efficiency
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What hypothesis gives a reason for why herbivores only consumes about 1/6 of producers' biomass yearly?
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The green world hypothesis
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Nutrient cycles are also called...
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Biogeochemical cycles
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What is the largest reservoir of carbon?
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Limestone
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Where is the main reservoir of nitrogen?
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The atmosphere
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What is the major pathway for nitrogen to enter an ecosystem?
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Nitrogen fixation by bacteria
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The largest accumulations of phosphorus are in...
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Sedimentary rocks from the ocean
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Why do the rate of nutrient cycles (carbon, nitrogen, phosphorus) vary between ecosystems?
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Because of the rate of decomposition
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What factors limit the rate of decomposition?
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The same as before; temperature, moisture, and nutrient availability
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T/F: The amount of nutrients leaving an intact forest ecosystem is controlled mainly by the plants
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True
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The critical load is...
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The amount of nutrients an organism can absorb without damaging the ecosystem
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When toxins become more concentrated in successive trophic levels, and thus more dangerous, it is called...
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Biological magnification
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T/F: Increased CO2 levels increases plant production, but not by very much
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True
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