#18-Species Diversity In Communities Flashcards
What is biotic resistance?
When interactions with the native species exclude the invader
What is source partitioning ?
Competing sale dies coexist by using resources in different ways
- reduces competition
- increases species richness
What is resource ratio hypothesis?
Species coexist by using resources in different proportions
What factors can moderate resource availability?
Disturbance
Stress
Predation
- promotes coexistence and diversity
What conditions make coexistence possible?
Changing conditions
- if superior species reaches carrying capacity then coexistence can’t be attained
What is the intermediate disturbance hypothesis?
Species diversity should be greatest at intermediate disturbances
- has the greatest species richness
What is important for maintaining species diversity?
Positive interactions
What are the lottery models?
Emphasize the role of chance in maintaining species diversity
- all species have equal chances of obtaining resources that were made available by disturbance
What are lottery models relevant to?
Very diverse communities
Species overlap in the resources they use
What are un-ideal conditions for lottery model?
Communities with large differences in strength interaction
What is the diversity- stability theory?
Species richness is positively related to community stability
As species richness increases, what happens to plant productivity?
It increases up to a threshold
What are the 4 hypothesis that explain the relationship between species diversity and community function?
- Complementarity hypothesis
- Redundancy hypothesis
- Driver and passenger hypothesis
- A variation of driver and passenger
What is complementarity hypothesis?
As species richness increases, there is a linearly increase in community function
What is the redundancy hypothesis?
The functional contribution of additional species reaches a threshold
