Download Chapter 48 - Community Ecology

Chapter 54 - grading rubric – 15 pts total
1. Explain the differences between competition, predation, parasitism, mutualism, and
commensalism and give an example of a pair of species that illustrates each.
½ pt definition, ½ pt example, 5 pts total
Competition – negative for both species, Example
Predation – beneficial to one species and detrimental to the other, Example
Parasitism- beneficial to one species and detrimental to the other, Example
Mutualism – beneficial to both species, Example
Commensalism – beneficial to one species and neutral to the second, Example
2. Describe the differences between Batesian and Müllerian mimicry. 1 pt total
½ pt – Batesian – a mimic looks like a toxic model
½ pt – Müllerian – two toxic species mimic each other.
3. Search for information on the internet on the relationship between Monarch and Viceroy
butterflies. Is this a case of Batesian or Müllerian mimicry? Explain your reasoning and give
the citation of your web resources.
½ pt – Although originally considered an example of Batesian, this example is probably better
explained as an example of Müllerian as both species are toxic to some degree.
½ pt – web citation
4. Explain the Competitive Exclusion Principle and how it relates to the concept of the
ecological niche. 1 pt total
½ pt - CEP – two species cannot overlap in requirements or one will die out and the other live.
½ pt - Niche – is the total requirements for the species. When expanded to the CEP, two species
cannot overlap in their niches without one dying and the other living.
5. Discuss if the Competitive Exclusion Principle explain the spacing of fast food restaurants on
the “strip” in most towns.
½ pt – Yes, fast food restaurants must use different niches in terms of food product, services,
toys etc. in order to exist with each other and compete for the same resource (money).
6. According to the principle of competitive exclusion, what outcome is expected when two
species (or business) with identical niches compete for a resource? Why? 1 pt total
½ pt – once species will survive, the other will go extinct (same with businesses)
½ pt - CEP says that two species cannot overlap in their niche and have both survive.
7. Describe what is meant by a “foundation” species and identify one example.
½ pt – a foundation species is one that alters the environment in a way that significantly impacts
other species in the community
½ pt – example – beaver, bison, elephant, other
8. Describe what can happen when a keystone species is removed from a community. Identify an
example of a situation where this has happened. 1 pt total
½ pt – the effect on the community is varied, but strong. The removal causes great problems.
½ pt – proper example
9. Discuss the differences between Primary and Secondary Succession. 1 pt total
½ pt - Primary – no previous life or soil
½ pt - Secondary – had previous life and/or soil
10. Choose an example of primary succession and describe the changes in the plant communities
and soil from the beginning community to the climax community. 1 pt total
½ pt – correct secondary succession example
½ pt – soil becomes richer in N, deeper, better water retention etc.
11. Discuss if “Smokey the Bear” is a good ecological concept for all communities (that is, always
prevent all fires and never allow burning).
½ pt - No - some communities require fire (prairies, chaparral, some forests).
12. Most prairies experience regular fires every few years. Speculate on what might happen if the
City of Muncie prohibits the burning of the tall grass prairie in Christy Woods for 25 years.
½ pt – the prairie would probably be replaced with trees or forest. Fire is needed to keep out
the woody plants and to replenish the nutrients from the standing dead grasses.
13. Discuss the most plausible hypothesis for why species richness is higher in tropical forests than
in temperate forests.
½ pt – energy levels are higher in the tropics due to increase sunlight. The higher energy levels
allows more species to share resources giving a result of higher species richness.
(or other acceptable answers).