AP Bio Chap 54 Community Ecology
1. What is a community?
2. Interspecific interactions are relationships between species in a community. ______
______occurs when species compete for a resource in short supply.
- can lead to ______or local elimination of a
competitive species
- What does Gause’s Competitive Exclusion Principle state?
- What is the ecological niche of an organism?
- What is resource partitioning?
- What is the difference in a fundamental niche and a realized niche?
- What is character displacement? Give an example.
Question: Two species of Anolis lizards are often found perched and feeding in the same trees, with species I in the upper and outer branches, and species II occupying the shady inner branches. After removing one or the other species in test trees, an ecologist observes the following results: Species I sis found throughout the branches of trees in which it is now the sole occupant. Species II is still found only in the shady interior when it is the sole occupant. What do these results indicate about the niches of these two species?
3. ______in an interaction in which one species kills and eats the other.
- What are some adaptations of the predator to be successful at this relationship?
- What are some adaptations of the prey? Include types of coloration.
- Name the following two types of mimicry and give an example:
- (a) harmless species resembling a poisonous or distasteful species ______
Ex ______
(b) mutual imitation by two or more distasteful species ______
Ex ______
4. ______is a interaction in which an herbivore eats parts of a plant or alga
- List some of the herbivore’s adaptations:
- List some of the plant’s adaptations:
5. ______is a relationship where two or more species live in direct and intimate
contact with one another. Give a + or - or 0 (no effect) for the following types:
a) Parasitism
b) Mutualism
c) Commensalism
- What is the difference in a obligate and facultative mutualism?
Question: Give types of symbiosis. If mututalism, be specific.
______Acacia Tree and Ants
______clown fish and sea anemones
______epiphytes and trees they live on
______cattle egrets and cattle that flush insects
______microorganisms in termites and ruminants
6. Two fundamental features of community structure are species diversity and feeding relationships.
- What is species diversity?
- It has two components: Define each.
a) species richness
b) relative abundance
- Two species can have the same ______but a different ______
______.
- A widely used quantitative diversity index is Shannon Diversity (H). Give the equation and what
each variable represents.
Question: Compute the Shannon Diversity of the sea urchin communities in two tide pools.
Pool 1 has three species with the following numbers: A = 8, B = ^, and C = 6
Pool 2 has four species of sea urchins with the following numbers: A = 14, B = 2, C = 2, D = 2
Which pool has the greater species richness?
Which pool has the higher Shannon diversity?
7. ______is the feeding relationships between organisms in a community.
- ______link trophic levels from producers to top carnivores
- ______diagrams complex trophic relationships
- With a food web, a food chain consists of ______or fewer links. According to the Energetic
Hypothesis, why is this so?
- Only about ______percent of the biomass (total mass of all individuals) of one trophic level is
converted to the biomass of the next level. How does the dynamic stability hypothesis explain this?
Question: Experimental data from tree hole communities showed that food chains were longest when food supply (leaf litter) was greatest. Which hypothesis about what limits food chain length do these results support?
8. Certain species have a large impact on community structure. What is a dominant species?
- Give two hypotheses that explain dominant species?
- How do invasive species become dominant?
- What is a keystone species? Give an example.
- What are facilitators? Give an example.
9. What is the difference in the bottom-up and top-down models of community organization controls?
Question: Many freshwater lake communities appear to be organized along the top-down model. What actions might ecologists take if they wanted to use biomanipulation to control excessive algal blooms in a lake with four trophic levels (algae, zooplankton, primary predator fish, and top predator fish)?
10. Even though it was traditionally thought that communities were in a state of equiblibrium, that idea has changed according to the nonequilibrium model, which describes communities as constantly changing due to disturbances.
- What is the intermediate disturbance hypothesis?
11. What is ecological succession?
- Distinguish whether the following are primary or secondary succession and why.
(a) vegetation on a volcanic island
(b) trees coming back after the fire in the Okeefenokee Swamp
(c) The climax community is the stable final stage of succession. What would be the climax
community in our area?
(d) Sometimes stages of succession can facilitate arrival of other species by improving the
environment. Others inhibit the establishment of later species. Some tolerate changes
from preceding species.
In the moraine succession of glaciers at Glacier Bay in Alaska, how did the Drayas and Alder
Trees impact succession?
(e) Describe dune succession. (You may have to look this up.)
12. Human disturbance to communities usually reduces ______.
We also prevent some naturally occurring disturbances which are important to community structure.
13. Community biodiversity is affected by biogeographic features such as ______
and ______.
a) It generally ______along an equatorial-polar gradients and is especially great in
the ______. .
a) Why do the tropics have greater biodiversity in terms of their climate and evolution?
c) Also, typically, a larger area has ______species.
14. Islands help ecologists to study factors that impact biodiversity. MacArthur came to the following
conclusions about island ecology.
- species richness on islands depends on:
a)
b)
c)
d)
Question:
15. Community ecology is useful for understanding pathogen life cycles and controlling human disease.
Pathogens can alter community structure quickly and extensively. The spread of pathogens has
been increased due to ______. ______
Pathogens have been transferred from animals to humans, called a ______.
This can be direct or through a vector. Examples? ______
Question: Why are ecologists trapping and testing migrating birds in Alaska?