Forest Ecology & Population Units
By David J. Kings, Valparaiso High School
Target Grade/Subject: A.P. Environmental Science
Unit Overview
There are two quotes that author Richard Louv presents in his book Last
Child in the Woods. The first is from poet Robert Frost.
When I see birches bend to the left and right . . .
I like to think some boy’s been swinging them.
The second is from a boy named Paul who is a fourth grader in a San
Diego school.
“I like to play indoors better ‘cause that’s where all the electrical outlets are.”
In the years that I have been teaching environmentally related high school
courses a vast majority of my students come into my classroom at the beginning
of the year reflecting the attitude of Paul rather than Robert Frost. There are
many whose attitude towards “the outdoors” is even more negative. Many
students, having spent most of their younger years indoors, are actually afraid of
being outdoors. There are obviously many reasons for this and many fingers to
point in many directions to assign blame. The media bombards us with “gloom
and doom” stories concerning the environment with oil spills, global warming,
recalled food products, invasive species, etc. Students (and in many cases their
parents) by not understanding how the earth’s ecosystems work, tend to
withdraw from it and take refuge in their electronics in the ‘safety’ of their homes
and never come out to get an understanding of the natural world. My goal in this
unit is to take one small step to try to instill that understanding. That goal is really
the goal of the entire course.
This unit is designed for 11th and 12th grade students taking the A.P
Environmental Science class. It is designed to introduce a number of topics early
in the school year that will be built upon both as the unit progresses and later in
the school year. The main topics will include forest ecology, plant identification
and classification, and abiotic and biotic population studies.
This unit is designed to meet the curriculum requirements for both the
Indiana Academic Standards for Advanced Environmental Science and the
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national A.P Academic Standards for A.P Environmental Science. The academic
standards from both of these sources are used to develop the curriculum for the
school.
The unit described in this paper will be an expansion of the current
curriculum covering the topics of forest ecology, plant identification and
classification, and abiotic and biotic population studies. For example, the
activities relating to classification and identification will be introduced due to the
identification of a weakness in these areas that has been recognized in the last
several years. Also, the forest population study is being introduced in order to
add a more “real world” lab to this portion of the curriculum. Due to time
restraints (50 minute periods), I have done proportionately more indoor than
outdoor labs over the last several years. It is a minimum brisk ten minute walk to
our school nature study area. However, I believe that by carefully planning each
day’s activities that occur outdoors the labs can be completed in a timely manner.
Sources Consulted / References
Unit Overview
Louv, Richard. Last Child in the Woods. Algonquin Books, 2008.
Wacky People dichotomous key worksheet
Johnson, Vivian. “Hotchalk LessonPlansPage.” Hotchalk, Inc. 2010.
<http://www.lessonplanspage.com/OWackyPeopleDichotomousKey612.htm
Nature Area dichotomous key activity
Koch, Rita. Presentation on Forest Community Types: Tree, Shrub & Plant ID.
Forest Ecology & Resources Teacher Institute, Michigan Tech University, June
28, 2010.
Shaw, T.E. Fifty Common Trees of Indiana. Division of Forestry, Indiana
Department of Natural Resources, 1981.
Leslie, Clare Walker. Nature Journaling. Storey Books, 1998.
Leslie, Clare Walker. Nature Drawing. Prentice Hall, Inc, 1980.
Tree Measurements Lab
Nagel, Dr. Linda. Presentation on Forest Ecology. Forest Ecology & Resources
Teacher Institute, Michigan Tech University, June 28, 2010.
Rivard, Jim. Presentation on Forest Measurements. Forest Ecology &
Resources Teacher Institute, Michigan Tech University, June 30, 2010.
Glenn, David, David Dickmann, and Donald Dickman. Forestry Field Studies.
NSTA Press, 2009.
Teaching and Learning Objectives
There are a number of objectives for this unit. The unit is designed to be
presented within the first few weeks of the school year.
The number one objective is to have the students become comfortable in
and start to understand the outdoor environment that they will be working in for
the entire school year. One of the final projects of the year involves the students
preparing and presenting environmental education programs for grade school
classes in our school system. Each group of two to three students must prepare
forty five minute to one hour program to classes ranging from kindergarden to
fifth grade. Last year the students presented to twenty seven classes and a total
of over seven hundred grade schoolers. Half of their grade comes from a critique
sheet done by the grade school teacher. Last year a number of the teachers
complained that while the presenting students knew their presentation, they did
not seem to have a great deal of knowledge of the area they were presenting in.
Plant identification was one weakness that was mentioned a number of times. I
hope to eliminate the problem in that area with these activities.
The second objective is to start to have students working in teams. One of
the things we have been hearing from interactions with the business community
in our city is that, while our students are academically prepared after graduation,
they do not work well in group, problem solving situations. Group observations
will tell if the lab and classroom activities in this unit will start this process
forward.
The third objective, since this is an A.P. class, is to make the A.P. required
content of this class more relevant to the students than strictly classroom
presentations could. I have heard a number of comments from students after
taking the A.P. test along the lines of “I kinda remembered us talking about that
last semester but I didn’t remember much of it”. I hope the more hands-on
approach will make the lessons and activities in this unit more memorable. Next
spring’s A.P. test scores will tell the tale.
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Content Benchmarks Addressed
The content benchmarks for this unit conform to Indiana’s Academic
Standards for Science as adopted by the Indiana State Board of Education in
March 2006. As of today, new standards have been written but have not been
formally approved by the Indiana State Board of Education so have not yet been
adopted by schools in the state of Indiana.
Env.1.3 Understand and explain that ecosystems have cyclic fluctuations, such as
seasonal changes or changes in population, as a result of migrations. This ties
in with the non-stationary aspects of the Parking Lot Lab.
Env.1.4 Understand and explain that human beings are part of Earth’s ecosystems and
give examples of how human activities can, deliberately or inadvertently, alter
ecosystems. The Tree Measurements Lab will look at areas that have been
impacted by human activities.
Env.1.8 Recognize and describe the difference between systems in equilibrium and
systems in disequilibrium. The maple forest part of the nature area is in
equilibrium. The over mature oak-hickory portion is not. The differences will be
explored and studied in the tree measurement lab.
Env.1.10 Identify and measure biological, chemical, and physical factors within an
ecosystem. Biological and physical factors will be explored in the tree
measurement lab.
Env.1.12 Explain the process of succession, both primary and secondary, in terrestrial
and aquatic ecosystems. Comparisons of the two plot types in the Tree
Measurements Lab will highlight how succession has caused the differences in the
plots.
Env.1.19 Demonstrate and explain how factors such as birth rate, death rate, and
migration rate determine growth rates of populations. Part of the Parking Lot
Lab analyzes these factors.
Env.1.23 Recognize and describe the role of natural resources in providing the raw
materials for an industrial society. Measurements done in the Tree Measurement
Lab will be analyzed partially to identify the economic value of the timber in the plots.
Env.1.26 Identify specific tools and technologies used to adapt and alter environments
and natural resources in order to meet human physical and cultural needs.
The measurement techniques in both the Parking Lot Lab and the Tree
Measurements Lab will highlight the tools and technologies used for this.
Env.1.27 Understand and describe the concept of integrated natural resource
management and the values of managing natural resources as an ecological
unit. This is one of the main goals of the Tree Measurements Lab.
Materials
Wacky People dichotomous key
Wacky People dichotomous key worksheet
Field sketchbook
Tree Dichotomous Key
Fifty Common Trees of Indiana book
Field sketchbook
Parking Lot Population Lab
No special materials required
Tree Measurements Lab
100ft/30m Fiberglass tapes Keson open reel (Forestry Suppliers #39970)
Diameter tapes (Forestry Suppliers # 39480)
Biltmore Sticks (Forestry Suppliers # 59760)
Yellow flagged utility stakes
Red flagged wooden stakes
Field sketchbook
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Classroom / Field Activities
The activities described here are sequential but do not necessarily follow in a day
to day order. Auxiliary materials and lesson components (textbook materials and
readings, lecture, and videos), in some cases, are added between the various
segments of the unit.
1. Plant Identification / Classification
1a. Dichotomous Key Use (1 class period)
The use of a dichotomous key is essential in studying the components of
any ecosystem, both biotic and abiotic. The first exercise is an in class, simple
lesson in how to use a dichotomous key. The object of this lesson is to either
refresh old freshman biology memories in the use and construction of a
dichotomous key or introduce them to those students who have never used or
constructed one.
A Wacky Dichotomous Key
•
The purpose of using the key is to name the creature shown.
Stick with one character until the name is reached, then go to the
next.
•
A dichotomous key gives instructions in pairs of statements. With
each character, start with the first pair of statements. Decide
which description describes your chosen character best and
follow the line to the right. There will either be a number or a
name. If it is a number, go to the pair of steps with that number,
for example, if the number is 3, go to steps 3a and 3b. If the line
ends in a name you have identified your character, so write it
down by the creature. Continue until each creature has a name.
There is only one creature per name, and no creature has two
names.
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1a Two feet
1b Some other
number of feet
Wacky People Key
2
3
2a Does not look 4
at all human
2b Looks a lot like 5
a human
3a One leg
3b Three or four
legs
6
7
4a Fly-like
4b Not fly-like
Mosk Cara
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5a Seems to be a Rita Nita
girl
5b Not a girl
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6a Leg is curled , Ru-ela.Brella
two feet
6b Leg is straight, Giggles
one foot
7a Three legs
7b Four legs
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8a Has webbed
feet
8b Clawed feet
Hex Oculate
9a Curly hair, no
toes
Lugio Wirum
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9b Wiggly looking C. Nile
mouth, three toes
on feet
10a Very long
Elle E. Funk
nose, open mouth
10b Some other 13
appearance
11a Has duck bill, Tri D. Duckt
two pinchers
11b No arms or
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pinchers
12a Has ears, tail, Grif Leon
and beak
12b Four eyes on Eggur Ondy
stalks
13a One eye,
webbed feet
13b Four stalked
eyes, four
pinchers
Cue Kide
14a Three toed
feet, nose like a
flower
14b Spider-like,
has spots
Tunia petalos
Quadrumenox
Patterned mulywumpus
Following the completion of the Wacky People Key, students will be
instructed to construct a dichotomous key in their field sketchbook using the
physical characteristics of each student in the class with the end point target of
each individual students name.
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1b. Tree Dichotomous Key (2 class periods)
This activity takes the previous exercise to the next level. The class will be
taken outdoors to our 7 acre district nature study area. This area is an old farm
woodlot that has not changed substantially in over 100 years. The area is
bisected from northeast to southwest by a stream. South of the stream is mainly
mature and over mature oak-hickory forest while north of the stream is mainly
regenerated maple forest.
This will be a two day outdoor activity. The class will be divided by lab
partner group into two groups. Each group will spend one day in the north part of
the nature area and one day in the south part of the nature area. Each lab group
of two students will have a copy of The Fifty Common Trees of Indiana book.
The book contains a dichotomous leaf key for the fifty trees described in the
book. All of the trees found in the nature area are found in the book. Trees to be
identified will be marked with plastic marker tape with a I.D. number written on
each. Each lab group will be instructed to identify the marked tree species found
in each of the two areas by using the dichotomous leaf key and recording its
identity by the corresponding number. Each student will make a field sketch of
each leaf in their field sketchbook using any of the techniques we have
previously used from Claire Walker Leslie’s books Nature Journaling and Nature
Drawing. These sketches can then be used for the lab practical test that will
follow.
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Forest Ecology / Population Studies
There are two outdoor lab experiences involved in this section. The first
involves introducing the students to population data collection and analysis. The
second takes that knowledge and expands it into a study of the population
characteristics and ecological implications of identically sized, scattered tree
plots.
2a. Parking Lot Population Lab (4 class periods)
This lab involves introducing the students to population data collection and
analysis through the use of the vehicles in the six acre student parking lot at our
school. Each lab group will count and collect data on every vehicle in four
parking lots that make up the student parking area. Due to the fact that data
collection takes place over two days, a number of characteristics of a biotic
population can be mimicked including migration and fact that all individuals in
many biotic population studies are not counted.
The first class period is spent explaining the lab and having the students
construct the data tables they will use when collecting data over the next two
days.
The second and third day are spent outside collecting data.
The fourth day is spent back in the classroom tabulating and analyzing the
collected data.
Lab reports will be prepared independently.
Parking Lot Population Lab
During this lab you will be studying and collecting data from an abiotic population and relating
your findings to the population characteristics of a biotic population.
This lab will take place in the student parking areas to the west of the school. The parking
areas are divided into four sections. (See attached map) Area #1 is the area south of the field
house. Area #2 is west of the field house. Area # 3 is north of the field house. Area #4 is the
northwest lot. (Affectionately known as the “Pot Lot”)
I will demonstrate the method for determining the length of your stride. Once you have
calculated your stride length, pace the length and width of each of the four parking lots.
Convert these measurements to feet and then calculate the area of each parking lot. Convert
the area of each lot to acres by dividing the area by 43,560 which is the number of square feet
in an acre.
The population you will be studying is the vehicles in these four parking areas. You and your
lab partner will collect data from every vehicle in these areas. The data you collect will include
the following.
1. Vehicle Type (Car, truck, or van - An SUV will be considered a truck)
2. Vehicle Manufacturer (Ford, GM, Chrysler, Honda, etc.)
This should be manufacturer not model. i.e. Chevy is manufactured by GM. List GM not
Chevy.
3. Vehicle Color (Just the eight basic colors - no aquamarine indigo, etc.)
With your lab partner, design and create a data sheet to record the three data categories for
each of the four parking areas as well as a place to tabulate your data for the entire parking lot
area.
You will have two class periods to complete the data collection portion of the lab. You and
your partner will be assigned a starting parking lot number. When you complete that lot you
will move, numerically, to the next lot. (i.e. if you are assigned Lot #3 as your starting lot you
will progress next to Lot #4, then Lot #1 and finish in Lot #2)
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Assessment
1. Normal Lab Report Format (one for every person - not one per lab team)
2. Data Tables (in pencil with rulered lines)
3. Lab Report Conclusion
a) What you learned, problems encountered, how could problems be solved, how could lab be
improved
b) Write a discussion covering the following topics:
1.
2.
3.
What problem(s) does gathering data over two days present?
What are the sources of error in this lab and how could they be minimized?
Explain how this lab resembles a biotic population study.
2b. Tree Measurements Lab (8 class periods)
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The purpose of this lab is to give students hands on experience in the
collection of tree stand data and the subsequent analysis of that data to
determine the health and viability of the forest where the data is collected. Part
of the A.P. Environmental Science curriculum is to impart the knowledge
necessary to determine the factors that make up a healthy ecosystem. The
intent of this lab is to provide that necessary knowledge. It is preceded by
classroom activities involving the class textbook, lecture and several video
segments pertaining to the topic.
The first day will involve going to each of the six plot so the students are
aware of their locations. The center point for each plot will have already been
made so as to avoid the overlapping of one plot with another. I will give a
demonstration of how to lay out each plot and the operation of the diameter tape
and Biltmore stick.
The second and third days will involve each lab group laying out and
marking the dimensions of their plot and practicing the use of the diameter tape
and Biltmore stick.
The fourth and fifth days the members of each lab group will identify,
measure and record the DBH and height of each of the trees greater than 4”
DBH in their plot.
The sixth and seventh days the lab groups will move to their second plot
(which, by now, have already been laid out by an earlier group) and repeat their
activities from days four and five.
The eighth day will be back in the classroom where students will tabulate
and analyze their data and do a formal lab report.
Tree Measurements
Objectives: To learn how to properly measure tree diameters, tree heights,
install fixed area plot for over-story and understory vegetation analysis, and
identify common sources of error associated with these activities and learn how
to avoid them.
Background: Trees are normally the dominant form of vegetation in the forest.
They serve many functions, including: wildlife habitat, water/soil quality, CO2
sequestration, and timber production. In order to develop a management
prescription for the forest, no matter what your goals, it is important to first have a
objective measurement of what is there. In addition, the cutting of trees is one of
the most important tools we have when it comes to furthering our management
objectives (better habitat, high quality timber production, diversity, etc.). Timber
management techniques are often used to facilitate non-timber related objectives
(i.e. snag creation, tree planting, stream crossing/water quality improvements,
etc.). When working with a plot it is important for you to be able to look at the
forest, take some measurements, and determine what options are available and
what the cost might be.
Once you become proficient, you should be able to look at a tree and make a
good determination of the DBH and number of sawlogs and/or in the tree. This
takes time and experience.
Materials: Diameter tape, reel tape, Biltmore stick, yellow flagged utility stakes,
red flagged wooden stake.
Measuring Diameter: We will use d-tapes to measure tree diameters. Please
note the importance of pulling the tape taut and making sure it is level on the
tree. Letting the tape droop low on the backside of the tree is a common source
of error. The formula for circumference of the tree is built into the tape.
Measuring Height: Biltmore sticks will be used to measure tree heights. Refer
to the attached handout for the proper use of the Biltmore stick for measuring
tree heights.
Procedure:
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Note: Lab groups should consist of not less than four or more than five
individuals.
1.
Three plot centers have been placed on the north side of the stream and
three plot centers have been placed on the south side of the stream.
These are marked with three foot wooden stakes with a red tape tied to it.
Your lab group will be assigned one plot to work with to start. Your group
will have a second plot on the opposite side of the stream to complete
after your first plot is finished. Use the reel tape and the eight yellow
flagged utility marking stakes to lay out a 37’3” radius concentric circle
from the plot center. This will give a study plot of 1/5th of an acre.
2.
Tree diameters are normally measured at DBH (diameter at breast height)
which is defined as 4.5’ above the ground. Work with one of your lab
partners to determine exactly where DBH falls on your body.
3.
I will give a demonstration on the proper technique for measuring DBH with
the diameter tape and height with the Biltmore stick. Practice on several
trees and compare your measurements with your lab partners to be sure you
are getting the same measurements.
4.
With your lab team members, measure the DBH and height of every tree 4”
or larger DBH within your study plot. Record your data in the attached data
table. Be sure to list the species of each tree you measure.
5.
In your field sketchbook make a scale map of each of your plots.
Locate each of the trees in its correct location on your map and identify
it by species, diameter and height.
6.
In your lab report conclusion, answer the following questions:
a. What are the predominant tree species in each of your plots?
b. Which of your two plots seem “healthier”? Give a detailed explanation for
your answer based on what you have learned about forest ecology and your
own observations of each plot.
c. Describe, in detail, what you think would be a viable management plan for
each of the two plots you studied.
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Overall Unit Assessment
There will be a number of assessment methods used for the various
portions of this unit.
Wacky People Key
The paper key itself will not be assessed for a grade. We will conduct a
short discussion on the assignment.
The key constructed by the students to identify the members of the class
will be assessed by other students in the class to determine the usefulness and
accuracy of the key.
Tree Dichotomous Key
The tree key will be assessed by having a lab practical exam. The exam
will consist of thirty stations spread throughout the classroom. Each station will
contain a unlabeled herbarium mounted leaf. Each student will have sixty
seconds to identify the leaf using their memory or the illustrations that they made
in their field sketchbook before being told to move on to the next station.
Parking Lot Lab
The parking lot lab will be assessed through the use of a standard lab
report with emphasis on the answers the students provide in the assessment
portion of the report.
Tree Measurements Lab
The tree measurements lab will also be assessed through the use of a
standard lab report with emphasis on the answers the students provide in the
assessment portion of the report. In addition, the methodology in the use of their
field sketchbook for this lab will also be assessed.