Ecosytems Flashcards
Define net primary productivity
Total chemical energy available for plant growth, plant reproduction and energy transfer to other trophic levels after respiratory losses.
Define gross primary productivity
Total chemical energy in plant biomass within a given volume or area
What is the relationship between NPP and GPP?
NPP = GPP -R
What is biomass?
Total dry mass of tissue or mass of carbon measured over a given time in a specific area
Why does biomass decrease at each trophic level?
- Energy lost in nitrogenous waste (urine/ faeces)
- Some of the organism is not consumed
- Energy lost to surroundings as heat
What is teh equation for efficieny?
energy converted into a useful form x 100 / total energy supplied
Define ecosystem
All the living organisms found in one area, combined with non-living aspects of the environment
Define community
All the different species that live in one area and interact with each other
Define population
All the individuals of a species that live in the same habitat at a given time.
Define habitat
The place where an organism lives wihtin the ecosystem
List some biotic factors
predators
disease
Define a niche
The role of a species within its habitat, consisitng of both biotic and abiotic interactions.
What is interspecific competition?
organisms of two differnet species who compete for food/ shelter etc..
What i smeant by primary succession?
Where an area previously devoid of life is colonised by a community of organisms
