CH 16
The hypothesis that predicts that intermediate levels of disturbance promote higher levels of diversity.
Intermediate disturbance hypothesis.
A summary of feeding interactions within a community can be diagramed in a ___ ___.
Food web.
Effects of predators on prey that alter abundance, biomass, or productivity of a community across more than one part of a food web.
Trophic cascade
The first organisms to colonize following a disturbance.
Pioneer community
This type of community develops late successionally and can persist until disrupted by disturbance.
Climax community
This is an association of interacting species inhabiting a defined area.
Community
Species, despite low biomass, exert strong effects on the structure of the community they inhabit.
Keystone species
Herbivores are considered _____ consumers and occupy the _____ trophic level.
primary / second
Organisms that influence structure of landscapes, ecosystem or communitites.
Ecosystem engineers
BONUS: example we discussed? Beaver (or humans)
Standing in the shade on a hot summer day would be an example of a _____.
Microclimate
See powerpoint
The right side
Robert Paine removed this keystone species from rocky intertidal habitats to monitor community response.
Pisaster sea star
Which 3 nutrient cycles play prominent roles in ecosystems?
What are the 3 mechanisms of succession models?
Facilitation, Tolerance, Inhibition
What is net primary production (looking for the equation)?
Gross primary production (GPP) - respiration by primary producers.
A disturbance is a discrete event that disrupts an ecosystem. Give a natural disturbance example AND an anthropogenic disturbance example.
Natural: Drought, fire, tornado, tsunami, etc.
Anthropogenic: development, invasive species, pollution, habitat fragmentation, etc.
This occurs when the activities of one species indirectly (through an intermediary species) benefit another species without itself being helped or harmed.
Indirect commensalism
______ controls are influences of physical and chemical factors on ecosystems, while _____ controls are influences of consumers on ecosystem.
Bottom-up / Top-down
What are the 2 characteristics that may result in stability of a community or ecosystem?
Resistance: maintain structure &/or function in the face of potential disturbance
Resilience: bounce back after disturbance.
Give 3 examples of heterotroph categories.
Herbivores, detritivores, carnivores, omnivores.
(for example: autotroph = primary producers)
What are the 3 attributes that make up community structure?
Number of species, relative abundance of species, and kinds of species comprising a community.
What is the main difference between foundation species and keystone species?
Biomass.
FS: high biomass
KS: generally low biomass
____ is a key ecosystem process that breaks down organic matter (& release CO2). During this process _____ can occur (which is the conversion of nutrients from inorganic to organic forms).
Decomposition / Mineralization
Give an example of a landscape and some of the distinctive patches that make up that landscape.
Mountain: forests, meadows, bogs, streams
Urban landscape: parks, industrial districts, residential areas
_____ of the energy of one trophic level is available to the next trophic level.
~10%