Ecology Summative Projects
For each of these projects you will be in groups.  The group members are responsible for fairly delegating responsibility.  The project serves as your assessment for the ecology unit of this course.  You are only responsible for your topic.  However, connections made to other project topics will be taken into consideration if you have trouble completely fulfilling the requirements in a portion of your project.

If you cannot demonstrate a working knowledge of the ecological principals we have covered and how they apply to your topic, you will be required to complete an alternative project (which will be very similar to this project only there will be more specific guidelines).

-a presentation to last no less than 20 minutes.
-multimedia (i.e. PowerPoint) component.
-written report (typed, w/ bibliography, etc.)

1.Energy and Matter:

Measurements of the growth of tropical trees in Costa Rica show reduced growth that seems to be correlated with increases in average nighttime temperatures thought to be brought on by global warming. The hypothesis offered by the investigators suggests the increase in nighttime temperature has resulted in increased respiration rates in the trees. Unfortunately, the increase in respiration rate does not seem to be counter-balanced by an increase in the rate of photosynthesis. There also seems to be an increase in the rate of respiration of decomposers in the soil. (Scientific American, October 1998)

Describe the relationship between the respiration and photosynthetic rates and the overall rate of growth in the trees described above? How would an increase in respiration rate result in a reduced growth rate?

Include the following concepts in your explanation.

Uptake of CO2
Release of CO2
Net Primary Production
Production of Biomass

2.Energy and Matter:

Explain why minerals are considered to cycle in an ecosystem while energy flows through an ecosystem. Your answer should include an explanation of the concept of decomposition. Specifically describe the role of decomposers in the cycling of minerals. What are the decomposers getting out of decomposition?


a. Select a species of organism (any type you like) and list the factors that determine the biotic potential (intrinsic rate of increase) of a population of these organisms.

b. Explain the distinctions between density dependent factors and density independent factors that affect your population AND list 5 examples of each.

4.Populations: Logistic population growth is represented by an S-shaped curve.

Explain (not describe) why both the birth rate and death rate change from the early, to the  middle, to the late stages of population growth (see graph to the right). In other words, how are individuals affected and by what at these different population densities?

Explain what is meant by the term "carrying capacity" and describe how the changes in birth  rate and death rate relate to the concept of carrying capacity.

5.Ecosystems and Biomes:

a. Select a terrestrial biome. Tell where the biome is located, and provide a brief description of the biotic and abiotic factors in the environment (specifically the temperature, precipitation, soil characteristics, and organisms that make up the food web).

b. Describe the effect of each of the geographical factors in the table below in determining the climatic factors that affect the type of vegetation found in your biome.

23.5 degree tilt of earth
mountain ranges
global air circulation


a. Describe an event that causes a disturbance in an ecosystem of a particular biome (you choose).  Describe how the disturbance affects the plant and animal populations in the area.

b. Describe how the disturbance affects the soil in your ecosystem and how pioneer plants change the physical environment during succession.

c. Predict the fate of this ecosystem. Will it reach a climax community? Is it likely to be disturbed again? Could the term "disclimax" be applied to your description of succession? Why or why not?

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