#20-Energy Flow And Food Webs Flashcards
What are tropic levels?
Describe the feeding positions of groups of organisms in ecosystem
What are detivores?
Consumes feces and dead organisms
What is allochthonous?
External energy inputs coming outside of the system and going into the system
What is autochthonous?
Energy produced from within a system
Energy _____ with every tropic level
Decreases
What is a trophic pyramid?
Portrays the relative amounts of energy or biomass of each trophic level
Are the pyramids in terrestrial and aquatic system ps the same?
Aquatic pyramid is inverted
- inverted pyramids occur when productivity is the lowest
Do land herbivores consume more or less autotroph biomass than aquatic herbivores?
Yes
What is herbivor production limited by?
By the food available
3 reasons why herbivores don’t consume more biomass?
- Constrained by predators
- Autotrophs have defences against herbivory
- Phytoplankton is more nutritious for herbivores then terrestrial plants
What is trophic efficiency ?
Amount of energy at one level divided by the amount of energy at the trophic level immediately below it
What is consumption efficiency?
Proportion of available energy that is consumed
What is assimilation efficiency?
Proportion of ingested food that is assimilated
What is production efficiency?
Proportion of assimilated food that goes into new consumer biomass
Where does consumption efficiency the greatest?
Aquatic ecosystems
Higher carnivores
What is assimilation efficiency determined by?
Food quality
Physiology of consumer
- more likely in carnivores
Who digests food more efficiently?
Endothermic
- higher assimilation efficiency
Where do endothermic allocate most of their energy to do?
To heat production
- less room for growth and reproduction
What happens to the surface area to volume ratio as body size increases?
The ratio decreases
What is bottom up control?
Resources that limit NPP determine energy flow through an ecosystem
What is top down control?
Energy flows as governed by predator consumption rates at the highest trophic level. Which influence multiple trophic level below them
How can the troop levels change?
By addition or loss of a top predator or s predator in the middle of the chain
What are 3 factors that can control the number of trophic areas?
- Amount of energy entering via primary production
- Frequencies of disturbance
- Ecosystem size
- larger populations = more species diversity
What are food webs?
Conceptual model of the trophic interactions of organisms in an ecosystem
-more species = more complex web
Bioaccumulation
Can stay in the environment for a very long time
-in the tissues of organisms
Biomagnification
Transferred up and can increase concentration a they are consumed
What are ecological roles ?
Organisms are determined by their tropic interactions
- what they eat and what eats them
