BIOL 230 UBC EXAM QUESTIONS AND
ANSWERS GRADED A+ 2026
Beta diversity - ANS The change in species number and composition, or turnover of species,
as one moves from one community to another.
gamma diversity - ANS regional biodiversity over a large area with many types of habitats
alpha diversity - ANS The local species richness in a given location
biotic resistance - ANS ability of resident species to exclude/slow population growth of non-
native species
5 consequences of climate change on species invasion - ANS 1. pathways
2. environmental constraints
3. distributions
4. impacts
5. management effectiveness
resource partitioning - ANS the divergence of niches/resource use. Enables coexistence in a
community.
@COPYRIGHT 2026/2027 ALL RIGHTS RESERVED
1
, INCREASE diversity
REDUCE competition
resource ratio hypothesis - ANS species coexist by using resources in different proportions
Hutchinson's model - ANS tc = time one species to outcompete another
te = time environmental variation to act on growth of competing species
tc<<te, exclusion too fast
tc>>te, exclusion unaffected by environment variation
*tc = te*, coexistence
Intermediate disturbance hypothesis - ANS communities experiencing intermediate levels of
disturbance are more diverse than those at high or low disturbance levels
competitive displacement - ANS The best competitor uses the limiting resources, reducing
the weaker competitor's population growth to the point of extinction
Dynamic equilibrium model - ANS Disturbance freq, intensity + competitive displacement
rate combine to determine species diversity.
Max when disturbance and displacement are roughly equivalent.
Menge-Sutherland Model - ANS Predation + competition + physiological limitations, affected
by level of disturbance.
Predation at low disturbance, competition at intermediate, and physiological limit at high
disturbance.
@COPYRIGHT 2026/2027 ALL RIGHTS RESERVED
2
ANSWERS GRADED A+ 2026
Beta diversity - ANS The change in species number and composition, or turnover of species,
as one moves from one community to another.
gamma diversity - ANS regional biodiversity over a large area with many types of habitats
alpha diversity - ANS The local species richness in a given location
biotic resistance - ANS ability of resident species to exclude/slow population growth of non-
native species
5 consequences of climate change on species invasion - ANS 1. pathways
2. environmental constraints
3. distributions
4. impacts
5. management effectiveness
resource partitioning - ANS the divergence of niches/resource use. Enables coexistence in a
community.
@COPYRIGHT 2026/2027 ALL RIGHTS RESERVED
1
, INCREASE diversity
REDUCE competition
resource ratio hypothesis - ANS species coexist by using resources in different proportions
Hutchinson's model - ANS tc = time one species to outcompete another
te = time environmental variation to act on growth of competing species
tc<<te, exclusion too fast
tc>>te, exclusion unaffected by environment variation
*tc = te*, coexistence
Intermediate disturbance hypothesis - ANS communities experiencing intermediate levels of
disturbance are more diverse than those at high or low disturbance levels
competitive displacement - ANS The best competitor uses the limiting resources, reducing
the weaker competitor's population growth to the point of extinction
Dynamic equilibrium model - ANS Disturbance freq, intensity + competitive displacement
rate combine to determine species diversity.
Max when disturbance and displacement are roughly equivalent.
Menge-Sutherland Model - ANS Predation + competition + physiological limitations, affected
by level of disturbance.
Predation at low disturbance, competition at intermediate, and physiological limit at high
disturbance.
@COPYRIGHT 2026/2027 ALL RIGHTS RESERVED
2
