Flashcards in Week 6 Deck (38)
What is a food chain
A model that shows the flow of energy in an ecosystem
What is the source of energy to producers?
What are levels on the food chain called
What would happen if the producers population size is reduced?
The populations of the consumers would fall
What would happen to the population size if the primary consumer is reduced?
The population of the producers would do well and the secondary consumers will starve and compete more
What happens if the secondary consumer is reduced
If the secondary consumer is reduced the primary consumers will do well and maybe over populate and overeat producers and starve too
If the tertiary consumers were reduced
The secondary consumers would eat more of the primary consumers
How much of the energy pyramid do producers get
What percent do primary consumers get?
How much percent do secondary consumers get?
How much do tertiary consumers get
What percent of energy is transferred to the next tropic level?
What is the other 90% of the energy used for in organisms
The energy is used for living, growing and reproducing
Why are food charts important
They show how organisms depend on each other for energy
What does S stand for?
What does richness measure
Total number of species in an ecosystem
What doesn't richness take into account
Number of individuals proportion or distribution of each species within the ecosystem
What does H stand for?
Shannon diversity index
What is the Shannon diversity index and what does it account for?
It accounts for species abundance by calculating proportion of individuals compared to total number of individuals in the community
What is the formula for H or the diversity index
H= -SUM (Pi * ln (Pi))
What does Pi in the diversity index stand for?
Species abundance/total abundance in the community
What does Ln stand for?
What does E stand for m
Measure my to compare abundances of each species in the community
What does a low value of evenness mean?
One or a few species dominate
What does a high value of evenness mean?
All species in community have similar abundances
What does evenness values range from?
0 to 1
What does a 0 evenness signify?
What does a 1 signify in evenness?
It signifies complete evenness
Why is the formula for evenness?