4.2 Energy Flow

conversion of light energy from the sun into chemical energy

the position an organism occupies within a feeding sequence (food chain) producers occupy the first level and from then on then primary consumers occupy level 2 as they feed on them, etc.

further down in the chain, the carnivores eating each other less energy and biomass

the producers, the beginning of the food chain more biomass here

a model that represents how nutrients and energy are passed from producer to primary consumer and so on in a community

a diagram that shows how food chains are linked together into more complex feeding systems, representative of the feeding pathways in an ecosystem

chain is a simplified illustration of energy flow, while a food web is a more realistic depiction of an ecosystem. in a web, organisms can have more than one food source/predator, and can occupy more than one trophic level.

the arrows always point in the direction of nutrient and energy flow (not in the direction of who eats who)

sugars and lipids, released by cell respiration to produce ATP

heat

kinetic, electrical and light energy

energy of motion

energy caused by the movement of electrons.

energy produced by the vibrations of electrically charged particles

chemical reaction in which energy is primarily given off in the form of heat

the total mass of a group of living organisms biomass diminishes along food chains as less energy is stored expressed as dry weight per unit area

kJ m^-2 year^-1, the measurement in a pyramid of energy

the rate of generation of biomass in an ecosystem, expressed in units of mass per area per time

the production of light energy converted to chemical energy in organic compounds by autotrophs.

the amount of chemical energy as biomass that a producer creates in a given length of time

the amount of chemical energy that is NOT consumed by respiration (NPP = GPP-respiration)

sunlight is the initial form of energy in almost all communities (in some they use energy derived from chemical processes). light energy is converted into chemical energy via photosynthesis

energy flows through the ecosystem through the different trophic levels in the food chains

not all energy stored in organic molecules is transferred, but instead becomes lost by excretion, being unconsumed, respiration and heat energy (as it cannot be converted)

energy transformations are only about 10% efficient as 90% is lost between the trophic levels

the increase of a substance in a particular organism (the zoomed in version of biomagnfication)

the increase of a concentration of a substance at a particular trophic level (the zoomed out version of bioaccumulation)

a model of the amount of energy at each trophic level of a food chain and the flow of energy each level is one tenth of the size of the preceding level

a model that depicts the number of organisms at each trophic level in an ecosystem, similar to the energy pyramid

a model representing the dried mass of the living organisms at each trophic level of an ecosystem