BIOL378 EXAM QUESTIONS AND ANSWERS WITH COMPLETE
SOLUTIONS GRADED A++
a population is regulated when it shows...
1. persistence
2. boundedness
3. return tendency
tagging and tracking marmots
- mortality acted evenly on all age classes except 1yr
- predation and unsuccessful hibernation = high mortality
- heavier marmots survived better
patch dynamics
- rate of colonisation declines with distance
- risk of local extinction increases with decreasing patch size
- small patches support smaller populations
- patch size and isolation can have compensatory effects
mast seedings
- source of food for eg rats, birds
- climate change effects
- costs for the plant eg delayed reproduction, higher density dependent competition
pesticides
, - accumulate through the trophic levels
- when something is toxic to predators could also be toxic to birds
- bad: persistent and toxic combo
species distribution models
overview --> data --> model fitting --> assessment --> predictions
data used for species distribution models
- species observation points
- range map
- country records
- predicted suitable habitat
effect of diversity on ecosystem functioning (3x hypotheses)
More species = more ecosystem function
Macurthur 1955: diversity stability (gives greater ability to recover from disturbance)
Ehrlich & Ehrlich 1981: ecosystem resistance (declines with species loss)
Walker 1999: ecosystem redundancy (similar functional groups more expendable)
examples of ecosystem services
- provisioning services eg food, water
- regulating services eg biocontrol
- supporting services eg genetic diversity
- cultural services eg aesthetics, mental health
SOLUTIONS GRADED A++
a population is regulated when it shows...
1. persistence
2. boundedness
3. return tendency
tagging and tracking marmots
- mortality acted evenly on all age classes except 1yr
- predation and unsuccessful hibernation = high mortality
- heavier marmots survived better
patch dynamics
- rate of colonisation declines with distance
- risk of local extinction increases with decreasing patch size
- small patches support smaller populations
- patch size and isolation can have compensatory effects
mast seedings
- source of food for eg rats, birds
- climate change effects
- costs for the plant eg delayed reproduction, higher density dependent competition
pesticides
, - accumulate through the trophic levels
- when something is toxic to predators could also be toxic to birds
- bad: persistent and toxic combo
species distribution models
overview --> data --> model fitting --> assessment --> predictions
data used for species distribution models
- species observation points
- range map
- country records
- predicted suitable habitat
effect of diversity on ecosystem functioning (3x hypotheses)
More species = more ecosystem function
Macurthur 1955: diversity stability (gives greater ability to recover from disturbance)
Ehrlich & Ehrlich 1981: ecosystem resistance (declines with species loss)
Walker 1999: ecosystem redundancy (similar functional groups more expendable)
examples of ecosystem services
- provisioning services eg food, water
- regulating services eg biocontrol
- supporting services eg genetic diversity
- cultural services eg aesthetics, mental health
