Energy Flow Flashcards
What do food webs summarize?
Feeding relationship in a community
What are trophic dynamics?
Energy transfer from one part of the ecosystem to another
Through consumption, energy is transferred from the bottom to the top of the food web
Why are there only 3-4 trophic levels?
Energy losses limit number of trophic levels in ecosystems
What is the first law of thermodynamics?
The total amount of energy in the universe is constant
Energy is transformed, but not created
What is the second law of thermodynamics?
Entropy will increase over time in a closed system. When energy is transferred from one form to another, energy is lost, usually as heat
What is entropy?
The degree of randomness
What is a closed system?
An ideal system that does not allow for transfer of energy either in or out
How is energy converted in a food web?
Initially derived from sunlight through primary production
Then converted from one biological form to another
Why is energy lost as heat?
Because organisms are warm and their surroundings are often colder
What is Lindeman’s 10% rule?
Only 10% of energy consumed by a trophic level is assimilated and available to higher trophic levels
What are other limits to energy transfer?
Not all biomass is edible
Not all biomass is accessible to be eaten
High trophic level individuals occur at lower abundances than lower trophic levels
What can we learn from energy budgets?
The trophic bottom of primary producers is relatively big
The organic belowground matter stores a lot of energy
Consumer components = much smaller than the PP component
Ecosystems are inefficient systems
What are allochthonous inputs?
Organic matter derived or created in a community external to the one it is deposited in
What is a trophic cascade?
When a change in the population size of species in one trophic level changes/alters populations in the other trophic levels
What are the primary producers in the kelp forest ecosystem?
Kelp
