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What determines what lives where?
- energy flow
- nutrient cycling
- limiting factors / resource tolerance
- competition
- predator-prey relationships
- symbiotic relationships
- succession / disturbance
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Why is there so much stuff that lives by the equator?
- equatorial- constant, high solar energy
- favorable climate with no seasonality
- lots of energy to pass on to next trophic level
- Old and relatively stable
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symbiosis
- an interaction between two organisms living together in intimate association
- evolved together (coevolution)
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Succession
process of change in community/ecosystem structure & function over time
- flora / fauna composition
- soil development
- microclimate
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Primary Succession
- new surface is exposed; not previously vegetated
- soil development begins at the same time
- (sand dunes, plants growing in cracks of pavement, ect.)
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Secondary Sucession
- old vegetation/ecosystem removed
- intact soil exposed (relatively)
- ex: wildfires, volcano erruptions
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benefits of succession:
- soil development
- increased biomass
- increased organic matter / humus
- greater efficiency of nutrient cycling
- increased diversity (animals)
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(I) Disturbance:
"discrete, punctuated killing, displacement, or damaging of one or more populations that directly (or indirectly) creates an opportunity for new populations to become established"
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(II) Disturbance
"a relatively discrete event that disrupts the structure of an ecosystem, community or population & changes resource availability or the physical environment"
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disturbance regime
pattern of natural disturbance for an area
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Intensity of disturbance
physical energy of the disturbance
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Severity of disturbance
ecological effect on organisms, community, &/or ecosystem
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Frequency of disturbance
average number of disturbance events over a given time period
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