Lecture 26- Ecosystem Ecology Flashcards
How is an ecosystem defined?
A biological community of interacting organisms and their physical environment (includes abiotic factors)
What is gross primary production (GPP)?
The amount of chemical energy (typically expressed as carbon biomass) that primary producers create in a given length of time
What is the major reservoir for nitrogen?
Molecular nitrogen in the atmosphere
What is trophic efficiency?
The percentage of energy that consumers in one trophic level gain and convert into biomass from the total stored energy of the previous trophic level
The _____ _______ suggests that the length of a food chain is limited by the inefficiency of energy transfer along the chain
Energetic hypothesis
What is net primary production (NPP)?
The difference between the rate at which the plants in an ecosystem produce useful chemical energy (GPP) and the rate at which they use some of that energy during respiration (stored energy available to the next trophic level)
What is nitrogen fixation?
The chemical process by which atmospheric nitrogen is assimilated into organic compounds, especially by certain microorganisms as part of the nitrogen cycle
What is net secondary production?
The energy content available to the organisms of the next trophic level (heterotrophic equivalent of net primary production by autotrophs)
What is an endotherm?
An organism that is dependent on or capable of internal generation of heat (warm-blooded)
How is assimilation defined?
The biomass of the present trophic level after accounting for the energy lost due to incomplete ingestion of food (total energy used for growth, reproduction, and respiration, excluding energy lost in feces)
What is ammonification?
Process by which organic nitrogen is converted to ammonium
What is an ectotherm?
An organism that is dependent on external sources of body heat
What are detrivores and how do they obtain nutrients?
Decomposers (heterotrophs) that obtain nutrients from dead organic matter (breakdown and recycle organic materials back into environment)
What is nitrification?
Biological oxidation of ammonia to nitrite followed by the oxidation of nitrite to nitrate
True or False: A decrease in moisture in terrestrial systems increases primary production
False; An increase in moisture increases primary production in terrestrial systems
