Succession
What is the term for a relatively stable, mature community at the "end" of succession?
Climax community
What are the three main types of population dispersion?
Clumped, uniform, random
What is the difference between an endangered species and a threatened species?
Threatened species are at risk of becoming endangered, endangered species are at risk of becoming extinct.
What is biocapacity?
The ability of an ecosystem or region to generate resources.
What are two reasons clumped dispersion might occur?
Resource availability, social behaviors, predation, protection, etc.
What type of succession occurs after a glacier retreats and exposes bare rock? Why?
Primary succession because there is no preexisting soil/life
What is the common reason for uniform dispersion? Give an example.
Territorial behaviors: Birds nesting
Why are specialist species often more vulnerable to extinction than generalist species?
They depend on a narrower range of habitats or resources.
What does a population pyramid with a relatively narrow base and a wider middle generally indicate?
Declining birth rates and slower population growth.
What is the term for the disappearance of a species from one particular area, even though it still exists elsewhere?
Extirpation
An abandoned farm begins undergoing succession. Put these organisms in the order they would most likely appear: shrubs, hardwood trees, grasses.
Grasses → shrubs → hardwood trees
Is food availability an example of a biotic or abiotic and density-dependent or density-independent liming factor?
Biotic and density-dependent.
A habitat contains 12 different species and 300 total organisms. Calculate its biodiversity index.
12 / 300 = 0.04
Why might a country with a wide-based population pyramid continue to experience rapid population growth even if birth rates begin to decline?
A large proportion of the population is young and will soon enter their reproductive years.
What term describes the role of a species in its ecosystem?
Niche
How could an invasive plant species affect the process of ecological succession?
It could outcompete native species and change the types of organisms that establish during succession.
What population dispersion do dandelions display and why?
Random because their seeds are wind-dispersed, so as long as there are enough resources, they can grow
Two islands are the same size, but Island A is closer to the mainland. Which island would generally have a higher immigration rate, and how would this affect its equilibrium species richness?
Island A would have higher immigration, generally resulting in higher equilibrium species richness.
A population of 1,200 individuals decreases by 15% in one year. How many individuals remain?
1,020 individuals
A population of rabbits has a high birth rate but continues to decrease in size. Give TWO possible explanations.
High mortality, increased predation, disease, etc.
A volcanic eruption destroys a forest. Under what circumstances could the area undergo secondary succession instead of primary succession?
If soil remains after the eruption, secondary succession can occur, but if the lava formed new rock, it would be primary.
True or false (and explain): A stable population will never exceed its carrying capacity.
False, a stable population doesn't necessarily stay at exactly carrying capacity, it can fluctuate around it.
Why might a population that has recovered from a bottleneck event still be at greater risk of extinction?
Its genetic diversity may remain low, making it more vulnerable to disease and environmental changes.
A country's population is growing at 1.4% per year. Using the Rule of 70, approximately how long will it take for the population to quadruple?
100 years (50 years to double, then another 50 years to double again).
A country has a stable population, but its ecological footprint continues to increase. Give TWO possible explanations.
More resource consumption per person, more waste production, more resource-intensive lifestyles, etc.