BIO 171 EXAM 4 PRACTICE QUESTIONS AND
DETAILED SOLUTIONS
◉ Species evenness.
Answer: relative proportions of each species, relative abundance of
each species
◉ Species Diversity.
Answer: combine information on species richness and species
evenness
◉ Ecosystem services.
Answer: services provided to humans by the natural world
Ex: clean water, crop pollination
◉ Aboveground biomass.
Answer: biomass of vegetation above soil surface
◉ Biomass.
Answer: weight of living tissue per area per unit time
◉ Biodiversity impacts on NPP.
,Answer: nutrient additions, disturbances, herbivory
◉ Community Composition.
Answer: Determined by abiotic factors (temp, rainfall, soil, nutrients,
light, CO2 availability) and disturbances, succession, size of area,
geographic location
◉ Highest species/unit area.
Answer: near the equator
◉ Latitudinal species gradient.
Answer: Species richness declines from the equator to the poles
Species richness is highest in the tropics
◉ Latitudinal species gradient Causes.
Answer: Tropics have high rates of NPP-> temps are warm, so lots of
rain fall and lots of light -> high NPP -> high diversity
"tropics are a cradle"-> topical areas are older, more time for
speciation, higher diversity
"tropics are a museum"-> tropical areas have more stable climate, so
lower extinction rate
tropics have stronger biotic interactions->coevolution->drives
speciation
, tropics have a larger area->greater amt of resources->more niches-
>more species
◉ Species-area relationships.
Answer: all else equal, the larger geographic area of a community,
the greater the number of species
◉ Disturbances.
Answer: events that open up space and resources in a community;
tend to remove species, and do so in a density independent way
◉ Severe disturbances.
Answer: high intensity and high frequency
◉ Less severe disturbances.
Answer: low intensity and low frequency
◉ Primary succession.
Answer: destroys the soil community, happens after volcanic
eruption, after glacier moves thru an area, takes very long
◉ Secondary succession.
Answer: does not change soil, ex: fire in Yellowstone
DETAILED SOLUTIONS
◉ Species evenness.
Answer: relative proportions of each species, relative abundance of
each species
◉ Species Diversity.
Answer: combine information on species richness and species
evenness
◉ Ecosystem services.
Answer: services provided to humans by the natural world
Ex: clean water, crop pollination
◉ Aboveground biomass.
Answer: biomass of vegetation above soil surface
◉ Biomass.
Answer: weight of living tissue per area per unit time
◉ Biodiversity impacts on NPP.
,Answer: nutrient additions, disturbances, herbivory
◉ Community Composition.
Answer: Determined by abiotic factors (temp, rainfall, soil, nutrients,
light, CO2 availability) and disturbances, succession, size of area,
geographic location
◉ Highest species/unit area.
Answer: near the equator
◉ Latitudinal species gradient.
Answer: Species richness declines from the equator to the poles
Species richness is highest in the tropics
◉ Latitudinal species gradient Causes.
Answer: Tropics have high rates of NPP-> temps are warm, so lots of
rain fall and lots of light -> high NPP -> high diversity
"tropics are a cradle"-> topical areas are older, more time for
speciation, higher diversity
"tropics are a museum"-> tropical areas have more stable climate, so
lower extinction rate
tropics have stronger biotic interactions->coevolution->drives
speciation
, tropics have a larger area->greater amt of resources->more niches-
>more species
◉ Species-area relationships.
Answer: all else equal, the larger geographic area of a community,
the greater the number of species
◉ Disturbances.
Answer: events that open up space and resources in a community;
tend to remove species, and do so in a density independent way
◉ Severe disturbances.
Answer: high intensity and high frequency
◉ Less severe disturbances.
Answer: low intensity and low frequency
◉ Primary succession.
Answer: destroys the soil community, happens after volcanic
eruption, after glacier moves thru an area, takes very long
◉ Secondary succession.
Answer: does not change soil, ex: fire in Yellowstone
