Topic 2: Ecosystem Dynamics

an organism that can feed itself – able to convert inorganic carbon-containing compounds into organic compounds – e.g. plants - done thru photosynthesis

light dependent and light independent

the total amount of living tissue in a defined volume or area – often defined as the “dry weight”

the total biomass that autotrophs create through photosynthesis.

the biomass left over after the autotroph has used what it needs itself

organism that cannot manufacture its own food - eats plants/ animals

feeding levels!! - a group of organisms within an ecosystem which share the same relationship to the producers in the ecosystem

producers, primary consumers, secondary consumers (first level that feed on animals rather than producers), tertiary consumers

diagram that shows the linear flow of energy thru an ecosystem

similar to a food chain, but includes many interconnected ones

shows the total biomass of the organisms at each trophic level

the role a species plays in the ecosystem

the pop. size that the environment is able to support - given the availability of food, water, shelter, etc

prevents something from increasing

immigration, emigration, births, deaths

(births + immigration) - (deaths + emigration)

a change in the species structure of an ecological community over time

hardy species which are the first to colonise barren environments

an intermediate stage found in an ecological succession - each stage of succession

the end result of succession is called a climax community (stable, reaching equilibrium). They take a long time to become established and damage cannot be restored quickly (other terms: mature/ old growth)

succession that begins on lifeless ground where there is no soil, or the soil is incapable of supporting life – begins on newly exposed or created ground

• able to fixate nitrogen (or a symbiotic association with something that can) • tolerance to extreme conditions • rapid germination of seeds • ability to photosynthesise

begins in an area where a disrupted community already exists (eg. after a fire)

• stomatal density in plants - as CO2 level increases, density decreases • ice cores - one layer of ice per year - when the layers form, the ice traps samples of the atmosphere in tiny bubbles