ENVR1301 Chapter 4

Explain how tolerance limits (fig. 4.2) to environmental factors determine distribution of a highly specialized species such as the saguaro cactus. Compare this to the distribution of a generalist species such as cowbirds or starlings. What would the curve in fig. 4.1 look like for one of these species?
Productivity, diversity, complexity, resilience, and structure are exhibited to some extent by all communities and ecosystems. Describe how these characteristics apply to the ecosystem in which you live.
Resource partitioning (figs. 4.6, 4.7) is an important adaptive strategy. Explain resource partitioning, and think of an example in your local area.
Define keystone species and explain their importance in community structure and function.
All organisms within a biological community interact with each other. The most intense interactions often occur between individuals of the same species. What concept discussed in this chapter can be used to explain this phenomenon?
Relationships between predators and prey play an important role in the energy transfers that occur in ecosystems. They also influence the process of natural selection. Explain how predators affect the adaptations of their prey. This relationship also works in reverse. How do prey species affect the adaptations of their predators?
Competition for a limited quantity of resources occurs in all ecosystems. This competition can be interspecific or intraspecific. Explain some of the ways an organism might deal with these different types of competition.
Each year fires burn large tracts of forestland. Describe the process of succession that occurs after a forest fire destroys an existing biological community. Is the composition of the final successional community likely to be the same as that which existed before the fire? What factors might alter the final outcome of the successional process? Why may periodic fire be beneficial to a community?
Which world ecosystems are most productive in terms of biomass (fig. 4.17)? Which are least productive? What units are used in this figure to quantify biomass accumulation?
Discuss the dangers posed to existing community members when new species are introduced into ecosystems. What type of organism would be most likely to survive and cause problems in a new habitat?

Define:

Species

Population

Biological community

Ecosystem

Biome

Keystone species

Sea otters

Sea urchins

Orca

Tolerance limits

Indicator species

Critical factor

Tolerance range

Adaptation

Evolution

Survival of the fittest

Natural selection

Convergent evolution

Divergent evolution

Gene

Resource partitioning

Generalist (with respect to resource use and tolerance range)

Specialist (with respect to resource use and tolerance range)

Predator

Prey

Predation

Resource Competition

Interspecific competition

Intraspecific competition

Symbiosis

Commensalism

Mutualism

Parasitism

Batesian mimicry

Mimic

Primary productivity

Net primary productivity

Abundance

Diversity

Complexity

Constancy

Climax

Abiotic

Biotic

Extinct

Extant

All individuals and organisms in a community use the resources of that community and therefore affect the ecosystem functions in some way.

What happened to the giant kelp beds in California when sea otters were removed from the system.

Why are sea otters declining in numbers in the Pacific Northwest?

How do tolerance limits affect the ability of a species to live in a given location.

What are some conditions that are called ‘tolerance limits’?

List em.

How is ‘tolerance limit’ related to availability of resources?

Why does the least available resource set the tolerance limits for a species?

How does developmental stage, juvenile vs adult, affect tolerance limits and the conditions that set the tolerance limits?

What is a tolerance range?

How is it related to tolerance limits?

What are ‘indicator species’?

How do we use a species as an indicator?

How do we judge water quality by using ‘indicator species’?

List the conditions that critically limit a population.

What is a ‘critical factor’?

How is a ‘critical factor’ related to tolerance range/limits?

What ‘adaptations’ do species have for various ‘critical factors’?

What condition drives evolution?

How is survival of a particular organism related to evolution?

Describe survival of the fittest.

How is number of offspring produced related to evolution?

What is ‘natural selection’?

How does the environment ‘select’ an organism?

How does natural selection cause a species to be better adapted to its environment?

How is ‘natural selection’ related to ‘tolerance limits’?

How does a cow grazing only ‘tall’ Johnson grass cause the population of Johnson grass to consist of mostly shorter plants?

What is convergent evolution?

List some examples of convergent evolution.

Why do cheetahs run so fast?

How do ‘genes’ determine the ability of an individual to respond to environmental conditions?

How are genes related to tolerance limits?

Describe resource partitioning.

How does developmental stage (juvenile vs adult) affect resource partitioning?

How does feeding behavior affect birds in different parts of a tree canopy?

How is ‘prey’ related to ‘primary producer’?

How is primary consumer related to herbivore?

How is herbivore related to predator?

How is tertiary consumer related to predator?

How does predation affect evolution?

See the above question about cows and Johnson grass.

Compare and contrast Interspecific and Intraspecific competition.

Which one is more crititcal for a aspecies?

Why?

How does resource partitioning affect resource competition (both interspecific and intraspecific)?

What is ‘territoriality’?

How does territoriality affect intraspecific resource competition?

What is symbiosis?

Compare and contrast the different types of symbioses.

Give some examples of different types of ‘symbiotic’ relationships.

What is Batesian Mimicry?

Give some examples of organisms that use Batesian Mimicry.

Compare and contrast Primary productivity with NET primary productivity.

What does ‘primary’ refer to?

What does ‘net’ mean, in this context?

Compare and contrast Abundance and Diversity.

Where on earth is diversity high? Low?

Where on earth is abundance high? Low?

Why?

What is complexity?

How is complexity related to abundance, diversity, constancy, and homeostasis?

Compare and contrast Abiotic and Biotic factors.

What is succession?

What are pioneer species?

What are the characteristics of pioneer species?

Compare and contrast Primary succession and Secondary succession.

What is a ‘climax community’?

Compare and contrast Succession and Climax communities.

What is an equilibrium community?

How is equilibrium related to climax?

What is ‘migration’?

How does the migration of a new species disrupt an ecosystem?

How does the way that a new species uses ecosystem resources change the resource cycles in that ecosystem?

What does ‘extinct’ mean?

How does a migration cause the extinction of a species?

How is ‘extinct’ related to tolerance limits, resource competition, and succession?

Lecture Slides

TC Home | Environmental Science | Faculty | Ralph Hicks