Field Study Laboratory Report
The Report should consist of the following materials assembled in the order listed.
1) A formal written laboratory report.
2) A data sheet of your group’s measurements.
3) A spreadsheet and a color-coded double pie graph of the relative dominance and frequency of your class
data.
4) A detailed aerial sketch of your forest quadrants with a color-coded key.
5) A data sheet of pond organisms found.
6) A food web of your pond ecosystem. The food web should be color coded by relative population.
7) Sketches of the various pond organisms seen with the microscope. Write down the organism’s pond habitat
and the organism’s niche.
8) A labeled pond sketch including the list of pond plants.
Typed written report
Title:
This should include both studies. Give a brief description. Forest and Pond study is not enough.
Introduction/purpose:
Paragraph 1 – This paragraph is an introduction to the purpose of the forest section of the field study. The field
study was done in order to evaluate relationships between different tree species and both their frequency and
dominance. You must provide an explanation about the types of measurements that were made in order to
determine these relationships, and the way that you did them. Make sure to state that measurements were taken
to determine population size, basal area (area taken up by trunk on ground), and forest layer that trees primarily
occupy. You also need to define terms such as canopy, understory, relative dominance and relative frequency.
The paragraph will include the following things:
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study was done in an even-aged mature forest
A census of tree by species was taken to determine relative frequency (define)
tree circumference was measured to determine basal area and then used to calculate relative dominance
(define)
forest layer by species was determined visually and recorded
The type of relationships that exist among species in regards to dominance and frequency will be
evaluated with the gathered information.
Paragraph 2 -This is the paragraph where you hypothesize on the type of relationship that exists in the forest.
Make sure that your hypothesis is tied into the background information of the first paragraph. The class will
determine the five most significant species in regards to both dominance and frequency from the data analysis
and use these to evaluate the relationship between dominance and frequency. You will use these five to check
your hypothesis in your conclusion. You will choose one relationship for all species
The two relationships are:
A) Strong – dominance and frequency for a species is within 5 %
B) Opposing - dominance and frequency is at least 5% apart from one another for a species.
You must then explain why (most important) you chose that relationship.
Even though forest layer is not directly part of the dominance/frequency relationship, it should be included in
your discussion on why you chose that relationship. The amount of water and soil type are fairly constant for all
species—so do not enter into the hypothesis. Think about what abiotic factor is the biggest variable for the trees.
Do species respond to this factor differently? What determines how big a tree gets in size? What determines
how many individuals of a species occur?
The paragraph will include the following things:
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The purpose is to discover the relationship between relative dominance and relative frequency
The relationship will be based on the five most significant species in the study based on the data
analysis.
Define both relationships and choose one as a hypothesis (strong or opposing)
Explain why that relationship is chosen with your detailed hypothesis
Practice hypothesis….
Conclusion for Forest Study
Paragraph 3 – Evaluate your forest hypothesis and determine whether it is right or wrong for each of the five
top species determined as a class from the pie charts. It may be right for some and wrong for others. You will
need to examine and analyze your dominance and frequency data table and pie graphs. A positive difference
between dominance and frequency means the tree is more dominant than frequent. A negative difference means
it is more frequent than dominant. Do not restate all the numbers from your data section, just make the
statement. You must then explain your data. By doing this you will be stating why your hypothesis is right or
wrong for each of the five top species determined by your class. Discuss each of the three to five species
considering their growth rate, reproduction/germination rate, and light requirement (tolerance – very important).
The Following Should Be Considered and Explained in the Conclusion
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Is the hypothesis correct or incorrect for the 5 species that were chosen
Split the species into canopy and understory species
Define Shade Tolerance
In which forest layer are the shade tolerant species and why?
In which forest layer are the shade intolerant species and why?
How does sunlight affect the dominance for each of the five species (make sure to discuss them
individually!)
How does sunlight affect the frequency for each of the five species (make sure to discuss them
individually!)
Paragraph 3
Explain what was done at the pond study in order to create a pond food web and identify
organisms and their niche. Discuss the concept of food web biodiversity and keystone species.
Discuss the concept o invasive species and how impact the diversity and overall stability of the
pond.
 inventory all the species in the pond and determine relative population size
 create a food web to determine the biodiversity (define), and stability (define) of the
pond, and the presence of a keystone species (define).
Paragraph 4
Make a hypothesis about the health of the pond ecosystem by judging its biodiverstiy based on
your visual observations at the pond. This will be based on your estimate of the number of
organisms from each feeding niche as well as the presence of any keystone species. You are not
quantifying this with numerical values, so it will be your opinion based on your knowledge of
food webs and your observations at the pond.
 hypothesis on whether the pond is ecologically stable based on your observation of its
biodiversity and relative populations sizes of the organisms.
 Predict whether you think a keystone species is present and why. Give the name of the
species if your think there is one.
Procedures
Explain the procedures for both studies separately with the forest study first. They should be in
the form of a numerical list. Include only relevant information involved in data collection. The
determination of relative dominance, relative frequency, and forest layer will be the last step of
the forest procedure. The methods on data manipulation are not needed. The creation of a pond
food web by niche is the last step of pond procedures.
Data
Write the words (See Attached).
Conclusion
Paragraph 1 – Evaluate your forest hypothesis and determine whether it is right or wrong for
each of the three to five top species determined as a class from the pie charts. It may be right for
some and wrong for others. You will need to examine and analyze your dominance and
frequency data table and pie graphs. A positive difference between dominance and frequency
means the tree is more dominant than frequent. A negative difference means it is more frequent
than dominant. Do not restate all the numbers from your data section, just make the statement.
You must then explain your data. By doing this you will be stating why your hypothesis is right
or wrong for each of the five top species determined by your class. Discuss each of the three to
five species considering their growth rate, reproduction/germination rate, and light requirement
(tolerance – very important).
Paragraph 2 – From the analysis of the pond food web, you will determine whether or not your
hypothesis about the ecosystem's health was valid or not. Your conclusion, like your hypothesis,
is still an opinion but can now be supported with example from your web. In order to support
your statements; discuss the numbers of organisms per niche and the number of possible food
sources for consumers in order to justify its stability. Also look at the relative population of
each organism. Discuss the impact of invasive species on the pond stability. Reference the
chemical data of the pond water to assist in making your conclusion. You can now determine if
there are any keystone species present.