1. Competitive exclusion: One of the species disappearsfrom that area
2. Character displacement: both species continue to exist, but they divergeto occupy slightly
different ecological niches within the shared habitat
3. Co-existence at reduced carrying capacity: both speciescontinue to livein the area, but at
lower numbers of individualsper species
Deciduousvs. Coniferous: Example of competitive exclusion
Deciduous: Dominant here because of seasonal temperature variationand even precipitation among
-Outcompete conifers in summerbecause largerleaves meansgreater photosynthetic capacity.
Measuring Population Density:
Population at timetwo=Population at time one +births - deaths+ immigrants-emigrants
Intermediate Disturbance Hypothesis: Predicts that the highest speciesrichness occurs at an
intermediatelevel of natural disturbance. Low levelsof disturbance result in a lowamount of
habitats, whereas highlevelsof disturbance eliminatetoo manyhabitats to support diversity.
• Floods, forest fireetc. are large,infrequent disturbances that are often catastrophic.
• Natural disturbances playan important role in shaping landscapes and influencing ecosystem
Ecosystem Function: Includes the exchange of nutrients and energyamong plants, animals, and
their environments. End result of ecosystem processes.
• In a woodlot, there isusually a lot of carbon and leaf litter that decomposes to produce
• This results in a ton of organismslikeinsects, bacteria and fungi to exist to keep the logs and
branches from pilingup on the woodlot floor.
• Measure and compare growth rates of forest as compared to the age of the forest to calculate
the forest biomass.
• Can also measurethe lightto see the structure of the canopy and how much light isabsorbed
by the canopy and leaf biomass.
• Researchers are studying the relationship between productivity and biodiversity.There are • Researchers are studying the relationship between productivity and biodiversity.There are
many factors beyond control, so new project has seedlingsplanted under controlled
conditions to compare growths.
Ecosystem Service: Processes within ecosystems that provide resources likewater, clean air or
• Woodlots providecarbon recycling, animal waste filtering and filtering of watersheds.
• Alsodefined as benefits people obtain from ecosystems that can be put in one