Enrichment 11-1: Teacher Activity Notes
Measuring Species Diversity
Students learn how to measure the species diversity of an area by observing, recording data, and interpreting data for an outdoor area at their school.
observe and collect observations of animals and plants in the outdoors.
explain the term species diversity.
compare and analyze data they've collected with the data of classmates.
- Activity Guide
- Data Sheet
- Activity Report
- Pencil or pen; clipboard
- Field guides (optional)
- Hand lenses (optional)
- Metric rulers (optional)
You may want to prepare an outline map of the outdoor area ahead of time. You can either draw it on the chalkboard or create a handout. Give each study area a number for ease of reference. You can also take the class out the day before the activity and have students sketch their own maps.
Approximately two to three 50-minute periods
Math Students calculate and graph data throughout.
Social Studies The loss of biodiversity is currently a global, political, and economic issue. Students can discuss ways this issue crosses international borders.
Prerequisites and Background Information
Human disturbance tends to reduce species diversity in an area. Species diversity generally follows a continuum from a lower number of species in the most disturbed area to a greater number of species in the least disturbed area. For example, a listing of sites along this continuum might be
- building (most disturbed, low species diversity)
- parking lot
- asphalt playground
- landscaping and planter boxes
- grassy area in a park
- overgrown vacant lot
- meadow or forest (least disturbed, high species diversity)
Sometimes, however, human disturbance may enhance species diversity. For example, students may observe that a planted flowerbed is more diverse than a vacant lot. You may want to discuss with students why such a situation could occur.
Introduce Enrichment 11-1 by reviewing the terms biological diversity and species with students to emphasize that they will be looking for different kinds of species. Remind students that the point of this exercise is to count the species, not to identify them. They need only distinguish between species in order to record them. Encourage the use of any extra equipment, such as rulers for measuring leaf sizes or hand lenses for closer viewing.
The map is a vital tool when assessing biodiversity and comparing the species diversity of the sites. Students can visualize where sites are located in relation to each other and predict how this may affect diversity.
Have students design their own field notes sheet by brainstorming what a scientist would need to know to use the species diversity data.
Steps 1-2 Before taking the class outside:
- Define the study areas by using your map.
- Assign one group of 4 to 5 students to each numbered area.
- Explain your rules for student behavior outside the classroom.
Step 3 You may want to require each student to fill out his or her own Data Sheet, or have one person in each group record the whole group's observations. While students are studying their area, check periodically that they are
- thorough in their observations: checking for soil organisms, and under leaves and bushes.
- not disturbing the area excessively.
- actually observing the organisms they write down.
Step 4 When you come back into the classroom, draw a large chart like the one in Question 1 on the Activity Report. Have each group give you its data for their area.
Species diversity data can be analyzed in a variety of ways both in groups and as a class. The following are some questions to use in analyzing your data. You can also have students hypothesize before they go outside based on the way you plan to analyze the data.
- Does species diversity increase with habitat diversity? Compare sites that include several different “habitats” on campus: an area under a tree, a sidewalk with plants growing up through the cracks, a grassy field, a vacant lot, a landscaped flower bed. Look at whether the sites with more habitats in them also have more species.
- Is species diversity related to the size of the area observed? In general, a larger area is more likely to support a larger number of species. This is related to the likelihood of finding many habitats in a larger space. Greater habitat diversity means more niches for different organisms to fill.
- How does human disturbance affect the biodiversity of an area? Have students rank the sites from the one that is most disturbed by humans to the site that is most natural. See the Background Information for an explanation of the relationship between human disturbance and biodiversity. For any of the above questions, students can rank each site and make a graph comparing one of the above variables to species diversity. For example, put the number of species on the y-axis. Rank the sites from smallest to largest area and put this on the x-axis. Or rank the sites from most disturbed to least disturbed and put this on the x-axis.
Conclude Enrichment 11-1 by having students answer the questions on the Activity Report as a written assignment or as part of the class discussion.
Although all students should make observations, you can assign specific tasks to each student in the group. Roles and tasks could be divided as follows:
Facilitator: Acts as group leader, keeps people on task.
Field Recorder: Keeps notes and writes down all results of observations.
Timer: Keeps track of time.
Surveyor: Measures the area to be studied.
Reporter: Reports to the class the findings of the group.
You may want to require students to give evidence for the numbers of species they claim to have found (sometimes they get competitive and exaggerate their numbers).Have them write their direct or indirect evidence next to each item.
Extend Enrichment 11-1 by
- Having students make repeated visits to the same site during different times of the day. They could also visit the site over a period of days, or weeks, or during different seasons.
- Having students visit other sites and collect data using the same Data Sheet. For example, they could collect data from another part of the school grounds, on the way home from school, at home, or at a park nearby. Be sure to caution students not to enter private property without obtaining special permission from the property owner.
Use students' discussion and written answers to the Activity Report to assess if students can
identify species diversity in a variety of areas.
explain the factors that may affect species diversity.
demonstrate their ability to collect, analyze, and present data.
Enrichment 11-1 Activity Guide: Measuring Species Diversity (Student Reproducible)
How do scientists measure biodiversity? The most common method is to count the number of different kinds of organisms in an area. This number is a measure of the species diversity of the area. In this activity, you use the same methods that ecologists use to conduct a field study of the species diversity around your school. An important point to remember is that scientists try to have minimal impact on the areas they study. Do not step on plants unnecessarily. Don't disturb animals that aren't disturbing you. And dig up only a small amount of soil to examine microorganisms.
- Data Sheet
- Activity Report
- Pencil or pen
Step 1 Prepare your materials and fill out the top of your Data Sheet before you go outside so that you can concentrate on making observations when you are outdoors.
Step 2 Determine what area your group will study. On a piece of paper, draw a map of the area the whole class will study. Mark the boundaries for each group's field study area. Represent different kinds of bushes and trees by drawing the outlines of their shapes on your map. Add labels such as “sidewalk, tree, asphalt, path.”
Step 3 At your field site, write a description on your Data Sheet for every kind of plant and animal you see. The important thing is not to label or name every organism. Just describe how it is different from other organisms. Use detailed descriptive words and try to draw what you see. Use the back of the sheet or another piece of paper to draw organisms. Don't forget to leave the area as undisturbed as possible.
Step 4 Analyze the data from your group and your class by answering the questions in the Activity Report.
Enrichment 11-1 Data Sheet: Measuring Species Diversity (Student Reproducible)
Group Members ______________________________________
Location of Field Site _______________________________
Time of Day_______________ Length of Observation_______________
- Describe the physical characteristics of this area. Is it hot or cold? Is it sunny or shady? Is it wet or dry?
- Describe the most abundant plant (type of tree, shrub, or grass).
- What plant or other material covers most of the ground?
Plants Describe every different type of plant you can find in your area. Do not worry about specific names. You may also want to draw these plants.
Total Number of Kinds of Plants ______________
Animals Describe every different type of animal of which you see evidence. You may see an actual animal. But it's more likely you will see signs that an animal has been there such as tracks, nests, chewed leaves, or animal waste. You may also want to draw these animals.
Total Number of Kinds of Animals ____________
Enrichment 11-1 Activity Report: Measuring Species Diversity (Student Reproducible)
1. Make a chart like the one below for the data collected by the whole class. Record the number of species each group found and the location of the field site.
Number of Kinds of Plants
Number of Kinds of Animals
2. Look closely at the class data. Which two areas had the most species diversity?
3. Which two areas had the least species diversity?
4. Why do you think these areas have different species diversity?
5. Scientists often assume that they have not found every single species in a given area. How could you improve your study to try to find more species?
6. Now that you've had some first-hand experience measuring species diversity, what recommendations could you make to a group planning to study the species diversity in the tropical rain forest?
Enrichment 11-2: Teacher Activity Notes
Students analyze and compare two graphs. One graph shows the rapidly increasing rate of species extinction in the world. The second graph shows the rapidly increasing rate of human population growth.
explain the term extinction crisis.
interpret data about human population growth and species extinction.
Math Students interpret graphs in this activity.
Social Studies Students study population growth trends in this activity.
Prerequisites and Background Information
Students should have some basic graph interpretation skills.
Introduce Enrichment 11-2 by reviewing the concept of exponential growth with students before beginning the activity. As students work, make sure they notice the changes in the degree of slope for each graph. You may want to point out that the steepest parts of the graph show the most rapid periods of change. Encourage students to observe that both the rates of extinction and population growth are increasing most rapidly in the most recent time period.
Steps 1-3 Depending on how much help students need in interpreting the two graphs, consider discussing the following questions.
- What caused the shape of the curve on each graph?
- Why are these shapes similar?
- What are some possible connections between the data on these two graphs? (For example, students may infer that more people create more habitat destruction that causes an increase in extinction. You may want to point out that correlation Goes not prove cause and collect. Ask students to think about how this inference could be tested.)
To help students interpret the graphs, you may want to tell them to begin by taking the graph apart. First, they can examine what each axis represents. Then they can look at what direction the line is sloping to see if it indicates a downward trend, upward trend, or stasis. You may also want to ask students to find specific information in the graph by using a ruler to draw two lines from the plotted line to the axes.
You should point out that the scale on the y-axis on Graph A is exponential. It increases by powers of 10. The scale on Graph B is linear.
Extend Enrichment 11-2 by
- Explaining the effect one species extinction can have on an entire community. Review with students the ecological relationships in a food web. Ask, What happens if you remove a producer? a herbivore? a carnivore? You may also want to do Activity 3-1: Classifying the Players in a Willow Forest.
- Having students do library research to explore the following questions: What were human societies like when human populations started to explode? How did population sizes differ in a hunter-gatherer society, an agricultural society, and an industrial society? How do each of these methods of survival affect the number of people who can be supported? Students can choose to report on one type of society, analyzing the society and trying to explain how the society affected the habitats and wildlife around it.
- Discussing the relationship between population, technology, affluence, and impact on natural resources. Though population growth is a significant factor contributing to environmental problems, it is not the only one. Just as important as the number of people in a population is how those people use their resources. In August 1994, the United Nations held an international conference in Cairo, Egypt, on the topic of population and development. A wealth of discussion topics may be found in magazines and news articles about the UN Conference.
- Discussing the impact of human activities on wildlife and what happens when humans cause species extinction. This discussion can be used to lead into Enrichment 11-3: How Do You Value Biodiversity?
Use students' discussion and written answers on the Activity Pages to assess if students can
read and interpret graphs.
interpret apparent correlations.
explain why the growing rate of extinction is called an extinction crisis.
Enrichment 11-2 Activity Guide: Extinction Crisis (Student Reproducible)
Why are scientists today so concerned about the “extinction crisis”? New species evolve and old species die out, or become extinct, as a result of natural processes on the planet. Animals such as trilobites, stegosauruses, and woolly mammoths lived long ago but don't exist today. So why do many people think that an extinction crisis is taking place in rain forests and other parts of the world? In this activity, you analyze data on the rate that species are becoming extinct to answer this question.
- Resource 1
- Resource 2
- Pen or pencil
Step 1 Analyze Graph A: Annual Species Extinction and answer the following questions.
a. Explain in your own words the information given on this graph.
b. Look at the increase in the number of species becoming extinct annually between 1600 and 1900. Compare this with the increase in the number of species becoming extinct annually between 1985 and 1990. Use this difference to explain the term extinction crisis.
c. Give at least two possible reasons for the changes in the number of extinctions per year shown on this graph.
Step 2 Analyze Graph B: Human Population Growth and answer the following questions:
a. Explain in your own words the information given on this graph.
b. Look at the increase in the number of humans on the planet between 1600 and 1900. Compare this with the increase in the number of humans on the planet between 1950 and 2000. Use this difference to explain the term population explosion.
c. How would you explain the changes indicated by this graph?
Step 3 Now compare Graph A and Graph B and answer the following questions.
a. What similarities and differences do you see in these two graphs?
b. What possible relationships might exist between the data on one graph and the data on the other graph?
c. How could you determine if there was any actual relationship between the data shown on one graph and the data shown on the other graph?
d. What conclusions could you make about human population growth and species extinction?
Enrichment 11-2 Resource 1: Extinction Crisis (Student Reproducible)
Enrichment 11-2 Resource 2: Extinction Crisis (Student Reproducible)
Enrichment 11-3: Teacher Activity Notes
How Do You Value Biodiversity?
Students become more aware of what they value in nature by answering questions about the impact and importance of other living things on their lives. Students decide what kinds of organisms are important to them and why.
explain that preserving biodiversity often involves difficult decisions based on many conflicting sets of values.
make personal decisions concerning the value of biodiversity.
- Activity Guide
- Activity Report
- Pen or pencil
One 40- to 50-minute period
Social Studies Students explore their own opinions about a variety of issues.
Prerequisites and Background Information
One way of explaining the different reasons people value biodiversity is to place them under four categories: aesthetics, ethics, ecosystem services, and economics. Some people feel nature and biodiversity are important to humans only if they provide a direct economic benefit, such as the pharmaceuticals found in the rain forest. Others value biodiversity for the aesthetic pleasure they get from walking or camping in the wilderness. Usually, any reason students have for placing value on nature will fit in one of the four categories.
Introduce Enrichment 11-3 by reviewing with students the importance of respecting the opinions of others during discussions. This is critical in the discussion of many issues. The classroom atmosphere should be comfortable enough for students to speak without worrying that other students will make negative comments.
Values clarification can be an effective way to have students reflect upon what their values are, why they value certain things, and how they can look beyond themselves into the world around them. You may want to discuss the definition of value, allowing students to devise their own definition as well as using the one from the dictionary.
Specific questions could be assigned to small groups for later sharing with the class, rather than having all students complete all of the questions. To give students additional time to digest these ideas, this topic could be extended over several class periods by assigning a few questions for discussion on each of several days.
During the activity, the role of the teacher should be that of a facilitator who does not impose his or her own values on the discussion. If a student chooses not to participate in the discussion that choice needs to be respected.
Steps 1-3 The following are discussion points for the questions in the activity:
- Many students don't realize the number of things they use and see every day that are made from plant or animal materials, nor do they realize the amount of labor and energy it takes to make and transport these items. Thinking about the paper towels, furniture, cardboard, and junk mail that come from trees could help students see how much they take for granted.
- Often, people place more value on the furry, cute, dynamic animals than on other creatures that may be more important to the ecosystem. Microorganisms and decomposers like snails come at the bottom of most people's lists. But if we didn't have them, we'd be up to our necks in dead things and waste.
- When discussing any environmental issue, it is important to present more than just the conservationist, “save the planet” side. Students need to realize that the things they listed as valuable to them could come into conflict. Explain that there isn't always one right answer and that people sometimes need to make decisions based on their priorities.
Extend Enrichment 11-3 by having students gather other opinions on the topic of valuing biodiversity by constructing a survey of public opinion on environmental issues for the school, parents, or community. Opinion surveys lend themselves to graphing their results in order to make generalizations about a population's overall attitudes on a topic. Students can graph the results of their surveys if they create multiple choice questions. You may want to have students compare the results of their opinion surveys to the results of national opinion polls on similar topics. Alternatively, students could conduct interviews of other students, parents, or community members. Students can then give oral or written presentations of their findings.
Use discussion and written answers from the Activity Guide and Report to assess if students can
identify the potential conflicts that may arise when making decisions on environmental issues.
explain the logic and validity involved in forming personal opinions.
Enrichment 11-3 Activity Guide: How Do You Value Biodiversity? (Student Reproducible)
What do you value? What is important to you? Scientists, economists, and policy makers all over the world are currently trying to figure out how important biodiversity is to humans and what is valuable about it. In this exercise, you are asked to think carefully about what is important to you as an individual and as a human being living on this planet. You apply what you know to decide how you value biodiversity.
Step 1 Which people, things, or qualities do you value most and why do you value them? Answer the following questions individually.
a. List the five people, things, or qualities that you value most.
b. What characteristics do these people, things, or qualities have that make them valuable to you? (Are they useful? Are they beautiful? Are they people who support you?)
c. How much are these items worth to you? What would you be willing to give up or do in order to keep these items as part of your life?
Step 2 Discuss the following questions about how your life is affected by biological diversity.
a. What are five objects in your home that come from a plant or an animal?
b. Explain which would have a greater impact on your life and why you think so: if all the bears in the world became extinct or if all the snails in the world became extinct.
c. Bacteria, fungi, and other microorganisms are responsible for decomposing dead things and waste. What would happen if these organisms no longer existed on Earth?
Step 3 Answer the following questions individually. Then discuss your answers with your group.
a. In order to build a shopping mall, a developer wants to plow local fields that contain some of the last remaining populations of an endangered plant. Would you be for or against this decision? Explain your answer.
b. What if the land were to be developed as housing for low-income families or a retirement home for senior citizens? Would your decision be different? Why or why not?
c. If you won a lottery prize of $100, how much of it would you give to save an acre of rain forest?
d. Was it hard for you to put a dollar value on the rain forest? Why or why not?
Rank the five species in order of their value to you by arranging them on the continuum. Then explain your reasons for ranking them the way you did.
Suppose the organisms above were endangered, and you have to decide which three to save from extinction. Which would you save and why?