Biodiversity & Biogeography
How is biodiversity measured?
species richness - the number of different species
species evenness- similar numbers within each species
What are the 3 categories that would be found on a range of tolerance graph?
optimal range
zone of physiological stress
zone of intolerance
Explain TWO factors that differentiate primary succession from secondary succession.
primary - no soil and takes longer to reach a climax community
List the 4 ecosystem services.
What are provisioning, cultural, supporting, and regulating services?
What is an externality?
the cost or benefit of a good or service that is not included in the purchase price of that good or service or otherwise accounted for.
According to the theory of island biogeography, what type of island would have the fewest number of different species?
Far from the mainland and small in size
What are THREE abiotic factors that a species might experience a range of tolerance for?
pH, sunlight, temperature
Propose a way in which a scientist could determine if an ecosystem was approaching a climax community.
Record the biodiversity present; more biodiversity indicates later stages of succession.
Look for late successional species like oaks, hickory and maple
List 4 examples of a provisioning ecosystem service.
food
medicine
lumber
freshwater
What is an adaptation?
What is a trait that by random chance gives an individual a survival advantage in a specific environment. Over time, this trait will become more prevalent in the population as a whole.
Ecosystem A has 5 different species with the following abundances: A - 20%, B - 15%, C - 20%, D - 20%, and E 15%
Ecosystem B has 5 different species with the following abundances: A - 5% B - 25% C - 25%, D - 35%, and E 10%
Which has the higher biodiversity and why?
Ecosystem A
species richness is the same, but A has a more even distribution of each
What is an indicator species?
The species that experiences the consequences of environmental changes first is the indicator species.
Identify TWO examples of primary succession AND TWO examples of secondary succession.
primary - glacial retreat and volcanic eruption
secondary - forest fire and abandoned agricultural field
What are two examples of cultural services that a freshwater lake ecosystem provides?
recreation, tourism, mental health, spiritual health
What is habitat fragmentation? (do not use the world fragment in your answer)
How do humans cause this?
when a habitat is broken into pieces
deforestation, construction of homes and roads
Why is genetic diversity so important within a population of a particular species?
With higher genetic diversity, there is a higher chance that a favorable mutation will arise. This also increases the chances the population will be able to adapt and evolve in the event of a disturbance.
Explain how population fluctuates between the zones on a range of tolerance graph AND explain what that means for individual organisms.
Optimal - grow and reproduce (numerous individuals)
Stress - survive (few individuals)
Intolerance - death (no individuals)
Describe how the introduction of different plant species impacts the formation of soil during primary succession.
Lichens create soil from breaking down rock, the decay of mosses creates a thin layer of soil with few nutrients. As grasses and flowers are introduced and decay more nutrients are added and soil eventually becomes thick enough to support trees.
What are 2 regulating services that a forest ecosystem provides?
climate regulation (absorbs carbon from the atmosphere)
soil formation
What is the difference between a generalist and a specialist species?
a generalist can survive a wide range of environmental conditions or eat a variety of food (racoon)
- a specialist can only survive in a very narrow range of conditions or only eats one type of food (panda)
Provide an example of the following AND explain what they are.
1) invasive species
2) keystone species
answers will vary
Draw a Range of Tolerance graph.
graph must include the zones, title, axis labels and units, bell curve
Identify correlation between biomass, primary productivity, biodiversity and ecological succession AND explain why.
as succession progresses, all 3 increase
Increased species of plants (especially those larger in size) are more productive. This also supports more species of animals that can find habitats so the biodiversity and biomass go up as well.
Due to changing climate, some ecosystems are shrinking and others are growing.
Provide an example of EACH and explain how it may negatively impact humans.
shrinking - tundra (increased albedo, increased warming due to melting of the permafrost)
growing - desert (decreased productivity and water supplles)
How do environmental stressors affect biodiversity in an ecosystem?
Ecosystems with more species diversity have a better chance at recovery than those with low species diversisty.