BI 341-Ecology

Assessment 1 Sample

  1. A student who had been studying the climates of the world went on a backpacking trip in the Andes (mountains near the equator). She noticed that the changes in the vegetation as she went from low to high altitude were similar to those seen when going from low to high latitude. Explain her observation.


  3. Refer to the graphs you received. (Would be provided in advance)
    1. Describe the pattern you see in graph A.


    3. Explain the pattern you see in graph A


    5. Identify a data point that does not seem to fit the pattern and offer a possible explanation.



  4. Interpret the climograph provided. What things can you tell about the climate at this location. What can you infer about the soil there? What would you predict the plant life is like? Briefly explain your reasoning.
  5. Sally student went on a cross country trip during her break. She collected soil samples from all over the United States and carefully sealed them for analysis. Unfortunately, she labeled them with Post-it notes and she can no longer tell which samples came from where. Sally visited Konza Prairie in Kansas, the Mojave Desert in California, and a pine forest in Colorado’s Rocky Mountain National Park. Which sample came from where? Label the columns as Konza, Mojave or Pine and save Sally!













    N level




    Soil Depth

    0.5 M

    0.1 M

    3 M


  6. Below are 6 facts in no particular order. Make a causation map of the system with the independent variable(s) at the top and arrows from cause to effect. Remember that your map may not be a single straight line. (You can write out the facts or just use the numbers.)
  1. The Waskaganish area is very cold in winter.
  2. Winds blowing from the west pick up water vapor over Hudson Bay.
  3. The Waskaganish area lies at approximately 52o N. Latitude, east of Hudson Bay.
  4. Air arriving over the cold landmass in the Waskaganish area cools.
  5. The trees of the Waskaganish area are shaped like cones to shed snow.
  6. The Waskaganish area gets a lot of winter snowfall.


Assessment 2 Sample:

Life History

Data (would be provided in advance):

Figure 1. Survivorship curves for a population of Adelie Penguins at Cape Crozier 1967-1969.


In Class Questions (These would not be available to you in advance):

  1. Does banding seem to affect survivorship for Adelie Penguins? If so, when does it affect them most?



  2. What is the probability that a banded penguin of age 2 will survive to age 16?



  3. What are the most dangerous ages for an Adelie penguin?


Data (would be provided in advance):


Two barnacle species are found on the rocks in this area. Experimenters removed all individuals of species 1 in some plots. In others, they used cages to exclude barnacle predators. Each plot started with 60 barnacles of species 2.


No Predators


(predators present)

Barnacle 1 removed



Control (Barnacle 1 present)



The experiment is repeated above the high-tide line, an area that gets more sun and less water.

The same procedure is followed, but the results are different:


No Predators


(predators present)

Barnacle 1 removed



Control (Barnacle 1 present)




In Class Questions (These would not be available to you in advance):

  1. Make hypotheses that would explain the results of the first experiment.


  3. Make hypotheses that would explain the results of the second experiment.



Assessment 3 - Sample

1. Productivity and Biomass

DATA (provided in advance)

A pack of 15 wolves killed approximately 200 kg of prey per day. Their main prey, moose, only produce one or two young per year (mean = 1.2). Only 80% of the females breed per year. Assume the average moose killed by wolves weighs approximately 600 kg. The territory of this pack was 25,000 ha.

Questions: (not provided in advance)

    a. How many moose would it take to provide a stable food supply for a wolf pack this size?

    b. How densely would the moose have to be concentrated to support this population in this territory?

    c. If the moose ate several species living in this habitat (moose, elk, deer, and caribou), would their territory size increase or decrease?


    2. a. Describe the likely steps necessary to produce a highly toxic plant and an herbivore that specializes in eating that plant.



    b. How does that process lead to diversity in types of toxins?



    3. Why do oceans have such low diversity? Why do forests have such high diversity?



    4. How does removal of the top predator in a food web affect diversity?



     5. If temperature alone affects productivity, and precipitation alone affects productivity, why consider them together?



    Information for Final Assessment

    Review these data.
    You will be asked to evaluate the data and speculate on their meaning, just as you have done on the past two assessments.

Alewives (Alosa pseudoharengus) are small, herring-like fish that eat zooplankton. They are native to the ocean, but have been introduced to freshwater lakes, including the Great Lakes. A classic paper examined some aspects of their affect on native fauna. The researchers measured the average frequency of Daphnia (large zooplankton) and Bosmina (small zooplankton) in lakes. An additional lake (Crystal Lake) was surveyed before and 20 years after the introduction of alewives.

Frequency of individuals found in water samples:


Lakes without alewives (average of 4 lakes)

Lakes with alewives (average of 4 lakes)

Crystal Lake Before alewives

Crystal Lake 20 years after alewives introduced

Daphnia spp.





Bosmina spp.






Final Assessment


REREAD the questions AFTER you have answered them. Use only the space given.


  1. You have two study sites. One is a lake high in the Rocky Mountains. It is surrounded by rocks and the occasional pine tree. The other is a lake in a Milwaukee Park. Describe some of the major differences you would expect to find between your two sites.



  3. You have been asked to consult with the Nature Conservancy about designing a reserve for an endangered species. They have a limited budget.
    1. What are your 3 major criteria in deciding on what land to buy?


    3. Explain why these 3 things are so important.


  4. You have worked hard on your independent research project. This information will be archived on the internet where other students could use it. If another student had access to your data and others like it from other schools or years, describe one meta-analysis she could do.


  6. Use the data set you were given in advance to answer the following questions:
  7. a. Describe some major trends that you see.



    b. Using ecological concepts, make a hypothesis to explain these patterns.


    c. How could you test your hypothesis?


  8. Choose either oxygen or nutrients and explain:
  1. How does the level of this change as one goes from the ocean surface to the ocean bottom?

  3. Why do we see this pattern?



Note: Self assessments are provided with each assessment.

Last update: 8/31/04 by Rebecca Burton, Dept. of Biology, Alverno College