energy flow and food webs

Food chain

Energy stored is passed through the ecosystem in a series of steps of eating and being eaten

Tropic level

Feeding position of an organism

Detritus

Dead organic matter/once living organisms

Autochthonous energy

Energy produced by autotrophs within the system

Alloctonous energy

External energy inputs. Usually most important in faster moving streams/aquatic environments. Energy comes from terrestrial systems

Ecosystem size and amount of energy (primary production)

What two things can cause the number of trophies levels to increase

Disturbance frequency

What can cause the amount of trophies levels to decrease

Some is dispersed, some lost via respiration

Why is not all the energy being transferred from one tropic level to the next (2 reasons)

Food quality, number of consumers, consumer physiology

What does energy transfer depend on (3 reasons)

Tropic pyramid

Stack primary producers on bottom and add other tropic levels above

Tropic efficiency

Amount of energy transferred from one tropic level to the next

Consumption, assimilation, production

What are the three components of tropic efficiency

Consumption efficiency

Proportion of available biomass eaten

Assimilation efficiency

Proportion of consumed energy used by the organism ( much higher in carnivores)

Production efficiency

Amount of energy assimilated used to produce biomass

Food web

A complex representation of how species feed on each other in an ecosystem (food chains linked together)

Tropic cascade

Change in abundances of organisms at one tropic level influences energy flow at multiple levels

Top down control

Consumption by predators changes plant abundance via trophies cascades