UBC BIOL 230: 12.1 Island
Biogeography Theory(78
questions and answers with
all diagrams included)
What is sampling effect?
the larger the area observed the larger the diversity seen
How does sampling effect lead to non linear relationships between species
and area?
The pool of colonists from the mainland was fixed at a certain number of
species - by chance some might get left out in a smaller area. SAmpling
larger area allows more habitats to be viewed and intern more species that
fill the niches of this habitat
Why do larger island tend to contain more species?
Sampling Effect
-Larger area-> more individuals -> more species
Habitat Effect
-Larger area-> more habitats-> more species
What is the habitat effect?
Larger areas observed have a higher diversity of habitats which intern yields
a higher diversity of species
if you compared the species richness of an island to that on the mainland of
the same area, would you expect a different species richness (assuming
immigration levels are the same)?
No, since they occupy the same area, they would have the same amount of
richness
Why is the effect of area stronger for heterogeneous habitats rather than
those that are homogenous (2)?
,more individuals AND more habitat types influence heterogeneous habitats
that are large while homogenous only causes there to be more individuals as
area increasse.
What is the island biogeography theory?
Theory developed by MacArther and E.O. Wilson states that the number of
species established on an island represents a dynamic equilibrium between
the immigration of newly colonizing species and the extinction of previously
established ones
-Immigration only affects species richness if the species is not already
present, which becomes increasingly unlikely as the region fills up with
species
According to the equilibrium theory of island biogeography, island species
richness is affected by what?
-Extinction rates
-Immigration rates
What 2 factors affect island diversity?
-Island Area (Affects extinction rates)
-Island Isolation (Affects immigration rates)
You take a short walk through part of Pacific Spirit Park (PSP) and decide to
keep track of the number of plant species you encounter. On your walk, you
identify 2 species in the first 1 m of the forest and after walking for 5 m, you
have counted 10 unique species. What is the value of z for this 5 m portion
of PSP?
1
What is stock flux?
the number of species on an island can support in term of individuals
-Immigration adds to the stock and extinction removes from the stock
IMAGE
, the species-area relationship typically seen in nature
What does this show?
What determines whether a species is present or absent in a community
according to the lottery model?
random chance
As the number of species increases on an island, ___________ rates go up
extinction
What is the theory of limiting similarities?
coexistence between species is more limited by competitive exclusion when
species share niche properties
Biogeography Theory(78
questions and answers with
all diagrams included)
What is sampling effect?
the larger the area observed the larger the diversity seen
How does sampling effect lead to non linear relationships between species
and area?
The pool of colonists from the mainland was fixed at a certain number of
species - by chance some might get left out in a smaller area. SAmpling
larger area allows more habitats to be viewed and intern more species that
fill the niches of this habitat
Why do larger island tend to contain more species?
Sampling Effect
-Larger area-> more individuals -> more species
Habitat Effect
-Larger area-> more habitats-> more species
What is the habitat effect?
Larger areas observed have a higher diversity of habitats which intern yields
a higher diversity of species
if you compared the species richness of an island to that on the mainland of
the same area, would you expect a different species richness (assuming
immigration levels are the same)?
No, since they occupy the same area, they would have the same amount of
richness
Why is the effect of area stronger for heterogeneous habitats rather than
those that are homogenous (2)?
,more individuals AND more habitat types influence heterogeneous habitats
that are large while homogenous only causes there to be more individuals as
area increasse.
What is the island biogeography theory?
Theory developed by MacArther and E.O. Wilson states that the number of
species established on an island represents a dynamic equilibrium between
the immigration of newly colonizing species and the extinction of previously
established ones
-Immigration only affects species richness if the species is not already
present, which becomes increasingly unlikely as the region fills up with
species
According to the equilibrium theory of island biogeography, island species
richness is affected by what?
-Extinction rates
-Immigration rates
What 2 factors affect island diversity?
-Island Area (Affects extinction rates)
-Island Isolation (Affects immigration rates)
You take a short walk through part of Pacific Spirit Park (PSP) and decide to
keep track of the number of plant species you encounter. On your walk, you
identify 2 species in the first 1 m of the forest and after walking for 5 m, you
have counted 10 unique species. What is the value of z for this 5 m portion
of PSP?
1
What is stock flux?
the number of species on an island can support in term of individuals
-Immigration adds to the stock and extinction removes from the stock
IMAGE
, the species-area relationship typically seen in nature
What does this show?
What determines whether a species is present or absent in a community
according to the lottery model?
random chance
As the number of species increases on an island, ___________ rates go up
extinction
What is the theory of limiting similarities?
coexistence between species is more limited by competitive exclusion when
species share niche properties
