Investigation 1: Observing Our Ecosystem
Materials:
- Chart paper (optional)
- Digital cameras (or smartphones and tablets with cameras)
- Paper/notebooks and pencils
- Magnifying glasses (optional)
- Computers with internet access
- Project Noah website: projectnoah.org
Preparation:
Find a nearby location (area around your school, nearby park, etc.) for students to look for and record different organisms. Make sure to identify clear boundary lines (i.e. a sidewalk, playground, etc.), so that students keep within the designated area.
You will also need to create a Mission on the Project Noah website (www.projectnoah.org/missions/create). Once the Mission has been created, you will also need to add the names of your students, and create a password for them. Depending on your students’ level of comfort with technology, you may choose to briefly introduce the website to them prior to this lesson.
Instructional Sequence:
Have students think-pair-share the following prompt: What living things have you observed in your neighborhood?
Next, let students know that we will be studying our local ecosystem. Lead students in a class discussion and brainstorm, recording on the board or chart paper:
- What is an ecosystem?
- What is diversity?
- What term do you think we use for the diversity of living things? (Biodiversity)
- Is diversity of living things important for an ecosystem? Why or why not?
(Note: Encourage students to develop their own definition of these terms, and build on one another's ideas. These questions are meant to provide insight into students’ thinking for the teacher, and to address any misconceptions, or unclear understandings, during instruction. If students have not been introduced to the words “species” and “populations” before, then they should be included in this brainstorming, as students need to understand them to complete the investigations.)
Explain to students that they will be going into part of their local ecosystem to look at its biodiversity by observing as many different types of organisms as they can find. Encourage students to look for a wide variety of different birds, trees, fungi, etc. Ask students: What are some things we can look for to identify variation in living things? You may find it helpful to show a few images of variation in physical characteristics to help students practice. For instance, you can discuss how there are many different types of trees, each with their own shape of leaf.
Students will now go outside and explore the designated area, photographing and recording observations (qualitative: color, shape, texture, etc. and quantitative: number of leaves on a plant, etc.) of as many species as they can find. Students should be detailed in their observations so they can make the most accurate identification of the organism when they get back to the classroom. Tell students they do not have to worry about accurately figuring out the names of the organisms at this moment. Encourage students to carefully look under rocks, and inspect trees for insects and fungi.
Back in the classroom, students will use online resources to identify the different organisms they found. Introduce students to the Project Noah website, and have them log in to the class Mission page. Let students know that they will now be uploading a picture of each different type of organism they found. They will use Project Noah and other online resources (see below) to figure out what the organism is, and record it with their picture. Before they get started, lead the class in a brief discussion to guide their research:
- What are some research strategies to help identify an organism?
- How can you narrow down your search?
- What might you rule out of your search? For instance, if I’m looking for a type of bird, how can I eliminate, say, penguins from my results? (Discuss habitat, and our local climate)
When students are done identifying the organisms that they observed, compile a class list of all the different organisms (some students may have observed organisms that others missed).
After students have logged their organisms, have a final wrap-up discussion about their findings:
- What are some species you found in our ecosystem?
- What characteristics did you use to differentiate between and identify the species?
- Tell students that scientists often look at species diversity to measure the biodiversity of an area. Ask students to define “species diversity” based on what they did in their investigation. (You can have students think about the definition in pairs first before discussing as a class. You want students to arrive at the understanding that species diversity measures the biodiversity in a particular area by looking at the number of different species in the area and the abundance of each species in the area. Note: You may have to guide students to the second part of the definition, because so far, they have only actively participated in and seen the first part.)
- Based on the definition that we came up with for species diversity, what are the two ways we can measure the biodiversity (in terms of species diversity) of our ecosystem? (By counting the number of different species and by counting the number of individuals in each species.)
- Which way did we measure biodiversity in this investigation? (By counting the number of different species.) Discuss with students how we can measure the biodiversity of an ecosystem by counting the number of species in the ecosystem. This measurement is referred to as “species richness.” Tells students they participated in analyzing the biodiversity of the ecosystem when they observed and recorded the different species they found in the local ecosystem. We can say that the higher the number of different species, the more biodiversity we have in the ecosystem. For example, an ecosystem with 25 different species is more biodiverse than an ecosystem with 11 different species. As a class, how many different species did we find in our local ecosystem?
- Why might it be beneficial for an ecosystem to have a large number of different species?
- If one of the tree species (i.e. oak tree) in the ecosystems dies off, how will other species in the ecosystem be affected? Think about what role oak trees have in the ecosystem and how they interact with the other species.
- Keeping all this in mind, how do you think the biodiversity of an ecosystem indicates its health?
- What are some things you wonder about the living things in our ecosystem?
Have students complete and submit an Exit Slip answering the following prompt: Describe the biodiversity you observed in our ecosystem. Do you think this biodiversity is important for the ecosystem’s health and stability? Why or why not?
Sample Online Resources:
Accommodations:
You may provide some or all students with a graphic organizer to help guide them while they document organisms within their ecosystem. A simple chart listing different types of living things (trees, animals, birds, insects, plants, etc.) will help to organize students’ data, and also gently remind them to observe many different types of living things.
Assessment:
Students’ understanding will be assessed by their answers to discussion questions, both during whole class discussions, as well as one-on-one, and also by their Exit Slip. Students’ understanding of biodiversity and its importance is first gauged at the beginning of class in discussion, and again at the end in the Exit Slip. If students’ misconceptions persist to the end of the lesson, they should be addressed in the second investigation.
Investigation 2: Data Analysis
Materials:
- Paper/notebooks and pencils
- Clipboards (optional)
Preparation:
Have a good estimate of the square footage of the area students will be surveying. This will be used when students are calculating ratios and estimating population size.
As an accommodation for some students, or to save time, you can prepare a collection table ahead of time. This will allow more class time for students to collect and analyze data.
Instructional Sequence:
Begin this investigation by asking students to look at the class list (from the previous investigation) of all the different species that were observed and identified. Ask students to summarize what we found when we observed our local ecosystem. Next, ask students: Which type of organism (trees, birds, small mammals, etc. or producers, herbivores, carnivores, etc.) in our ecosystem do you think had the most diversity in its group?
Have students share their thoughts, then ask them: How can we better analyze the biodiversity in our ecosystem? As students discuss ideas, guide them towards the collecting of quantitative data. By collecting and comparing data, we are better able to communicate with others what we observed.
Ask students to recall the definition of species diversity. Yesterday they looked at measuring species diversity by identifying and recording the number of different species. Discuss with students how they can collect quantitative data to further measure biodiversity in terms of species diversity by counting the number of individuals of each species. This is referred to as “species abundance.” Species abundance is how many individuals are present in the population for each species. If an ecosystem has fifteen different species, but only one of the populations has 100 individuals and the other fourteen populations have less than 5 individuals each, then the ecosystem is not as biodiverse as we may have originally thought. When scientists consider the biodiversity of an area, they usually like to consider both the species richness (from Investigation 1) and the species abundance (which we will investigate now) to get the entire picture.
Students will look over the species that they observed in the prior investigation and create a chart to keep track of the number of individuals present in each species’ population in their ecosystem. They will then take their chart outside to track the number of individuals they see for each population. (Note: Depending on the time available or your students’ needs, you may decide to assign each student a different set of organisms in order to collect data on a wider array of organisms.)
Sample Collection Table
|
House Sparrow
|
III
|
|
American Homer Pigeon
|
II
|
|
N. American Gray Squirrel
|
I
|
|
Oak tree
|
IIII I
|
Upon returning to the classroom, call on students to share some of their data and compare it to what their classmates found. Guided discussion questions:
- Were you surprised by the data you collected? In what way?
- How does your data collection reflect measuring species abundance?
- What patterns did you see in the data? Why might there be more of X species and less of Y species (use findings from their data)? Are there certain types of organisms that consistently had higher population sizes than other types of organisms? (i.e. The plant populations are generally higher than animal populations. Have students start thinking about why we may see high population sizes for plants/producers compared to the consumers/animals. This will tie in to the next lesson about food webs.)
- Do you think the numbers for each population will remain the same over time? Why or why not? Which ones do you think are the most likely to change? Why (use your data in your reasoning)?
- Do conditions (resources, weather, etc.) in ecosystems always remain the same? If an ecosystem is faced with a change, such as a disease, what type of population (large or small) may be more resilient to the change? Why?
- Using the data that you collected, predict what will happen to the population numbers of four species if a fire disturbs your local ecosystem. Include data and reasoning. How will the overall health of the ecosystem be affected in terms of species diversity (both species richness and species abundance)? (Note: If there are current threats to the local ecosystem, use those threats as the disturbance example in this question instead of the fire.)
- What are some of the limitations of this data? Was our sample size large enough?
Finally, lead students in a whole class discussion about their findings from the past two investigations:
- What conclusions can you draw from our data?
- Why is species diversity essential to an ecosystem’s health? Think about what roles each species has in the ecosystem. Think about the relationships between species in an ecosystem.
- What might happen to other populations in the local ecosystem if the number of Y species doubled?
- If the amount of biodiversity decreases, what would happen to the overall stability/health of the ecosystem? What changes might you see in the ecosystem? Why?
- If an ecosystem only has two producers (two different types of trees), and one producer’s population completely dies off, how will the ecosystem be affected?
After a brief discussion, have students write up a conclusion of their findings for the day. In their conclusion, students should use their data to write an explanation for what biodiversity is, how biodiversity can be measured, and how the biodiversity of an ecosystem can indicate its health. Students should use their observations and data about different species and population sizes from both investigations as evidence in their explanation.
In the follow-up lesson, Backyard Biodiversity - Food Webs, students will dig deeper into analyzing the importance of biodiversity, and the interconnectedness between species.
Accommodations:
You may choose to provide some or all students with a pre-created table for students to use while collecting their data. You may also wish to assign students specific organisms to collect data on, in order to limit how many they must find and count; students would then share their findings as a class in order to compile all of the data. Some students may benefit from the use of a calculator to calculate ratios using their data; the focus of this lesson should be on their understanding of biodiversity, rather than computation.
Assessment:
- Formative: Students’ understanding will be assessed by their answers to discussion questions, both during whole class discussions, as well as one-on-one.
- Summative: Students’ understanding will be assessed by their collection and dissemination of data, and in their final written conclusion. Students’ learning will be evidenced in by their ability to analyze the data in order to explain biodiversity, and compare the population sizes of two or more species in our ecosystem.
Optional Extension:
Students can develop a graphic representation of their data by creating a pie chart or bar graph. They can choose what they would like to compare, and write a description of what their data shows, and what it might mean about the ecosystem.
Related Follow-Up Lesson:
The learning that takes place in this lesson can be built upon using the Backyard Biodiversity - Food Web lesson plan. In that lesson, students construct a model showing the transfer of energy within their local ecosystem. They then use this model to predict how a decrease in one species population would impact the rest of the ecosystem over time.
