ecosystem Flashcards
what is stratification
vertical distribution of different species occupying different levels.
what are the aspects of an ecosystem
- productivity
- decomposition
- energy flow
- nutrient cycle
what is the direction of energy flow in the environment
it is unidirectional towards the higher trophic level
what is primary productivity?
the amount of organic matter produced per unit area over a time period by plants during photosynthesis. measured in weights and energy
what is the formula to calculate GPP
npp + r
r is respiration loss
what is net primary productivity
amount of biomass available for the consumption of heterotrophs
what is secondary productivity
rate of formation of new organic matter by consumers
what is the annual NPP?
170 billion tonnes
the productivity of the oceans is
55 billion tons
what is leaching?
water soluble inorganic matter go down into the soil and precipitate as unavailable salts
what is catabolism?
bacterial and fungal enzymes break down detritus into simpler inorganic substance
what are the steps that occur simultaneously on the detritus?
fragmentation leaching catabolism
what are the steps that occur during decomposition in the soil?
humification and mineralisation
what serves as a reservoir of nutrients and why ?
humus as it is colloidal in nature
decomposition is largely a _ requiring process
oxygen
