biotic factors forest unit-kellie · pdf filein this unit, students will study how abiotic...

Biotic Factors in a Forest Ecosystem By Kellie C. Huhn

Target Grade: 6th grade science Unit Overview In this unit, students will study how abiotic factors affect biotic elements in an ecosystem. Students will begin their study of biotic and abiotic elements in ecosystems by building their own terrariums and designing and conducting scientific investigations addressing the changes in plant growth caused by different soils. In our school, 6th grade science begins with the study of ecosystems. In the ecosystems unit students:

Explain the flow of energy between producers, consumers and decomposers,

Identify and describe examples of populations, communities and ecosystems,

Describe common patterns of relationships between and among populations (competition, parasitism, symbiosis, and predator/prey)

Identify the biotic and abiotic factors in an ecosystem and describe how those factors influence changes in population size,

Describe how humans purposefully or accidentally alter the balance in ecosystems, and

Predict and describe possible consequences of overpopulation of organisms. We begin the year focusing on observation skills and develop a rubric defining key characteristics of detailed observations. In the Earth’s History unit, students describe the composition of soil in the context of weathering, erosion and the rock cycle. Sources Consulted/References

“Do You Dig Wetland Soil?” WOW! The Wonders of Wetlands. The Watercourse and Environmental Concern Inc., 1995, p. 231‐238 http://www.envirothonpa.org/documents/digwetlandsoil.pdf

“How Thirsty is the Ground?” WOW! The Wonders of Wetlands. Bozeman, Montana, 2004, pp. 239‐244.

“Soil Stories,” p. 297 – 302, Project Learning Tree, Environmental Education Activity Guide, 2011

“Field, Forest, and Stream,” p. 203‐206, Project Learning Tree, Environmental Education Activity Guide, 2011

“Rain Reasons,” p. 123 – 129, Project Learning Tree, Environmental Education Activity Guide, 2011

Hand –On Ecology: Real‐Life Activities for Kids, Colleen Kessler, 2007, pp. 68 – 72.

Ecosystems, Science and Technology for Children, National Academy of Sciences, 2004, pp. 13‐23.

Field Museum, Underground Adventure Lessons, http://archive.fieldmuseum.org/undergroundadventure/teachers/index.shtml

Michigan Science GLCEs: http://www.michigan.gov/documents/mde/Complete_Science_GLCE_12‐12‐07_218314_7.pdf

Michigan Mathematics GLCEs: http://www.michigan.gov/documents/MathGLCE_140486_7.pdf

Michigan Social Studies GLCEs: http://www.michigan.gov/documents/mde/SSGLCE_218368_7.pdf Teaching and Learning Objectives In this series of lessons, students will:

Identify biotic and abiotic components of an ecosystem

Describe soil as a mixture of weather‐eroded rock and decomposed organic material

Compare different soil samples based on particle size and texture.

Design and conduct scientific investigations to study the soil affects plants in an ecosystem.

Use tools and equipment to collect data during the scientific investigation

Construct charts and graphs from data and observations

Use the data from the investigations to describe how abiotic factors influence changes in plant populations.

Content Benchmarks Addressed: Science:

L.EC.06.31 Identify the living (biotic) and nonliving (abiotic) components of an ecosystem.

L.EC.06.32 Identify the factors in an ecosystem that influence changes in population size.

E.SE.06.13 Describe how soil is a mixture made up of weather eroded rock and decomposed organic material.

E.SE.06.14 Compare different soil samples based on particle size and texture.

S.IP.06.11 Generate scientific questions based on observations, investigations, and research.

S.IP.06.12 Design and conduct scientific investigations.

S.IP.06.13 Use tools and equipment (spring scales, stop watches, meter sticks and tapes, models, hand lens, thermometer, models, sieves, microscopes) appropriate to scientific investigations.

S.IP.06.15 Construct charts and graphs from data and observations.

S.IP.06.16 Identify patterns in data.

S.IA.06.11 Analyze information from data tables and graphs to answer scientific questions.

S.IA.06.12 Evaluate data, claims, and personal knowledge through collaborative science discourse.

S.IA.06.13 Communicate and defend findings of observations and investigations using evidence.

S.IA.06.14 Draw conclusions from sets of data from multiple trials of a scientific investigation.

S.IA.06.15 Use multiple sources of information to evaluate

S.IA.06.15 Use multiple sources of information to evaluate strengths and weaknesses of claims, arguments, or data.

S.RS.06.11 Evaluate the strengths and weaknesses of claims, arguments, and data. Social Studies:

6 – G3.2.1 Explain how and why ecosystems differ as a consequence of differences in latitude, elevation, and human activities (e.g., South America’s location relative to the equator, effects of elevations on temperature and growing season, proximity to bodies of water and the effects on temperature and rainfall, effects of annual flooding on vegetation along river flood plains such as the Amazon).

Math:

A.RP.06.08 Understand that relationships between quantities can be suggested by graphs and tables.

Lesson 1 (Day 1): Objective: Students will observe different soil samples and record their observations. Students will begin to use texture to differentiate types of soils.






I. Preparation:

Prepare sand, silt and clay soil samples.

Gather samples from school area.

Buy potting soil.

Set up supplies for each station

II. Materials Needed:

Chart paper,

Copies of “Key to Soil Texture by Feel,” “Soil Observations – Day 1,” “Observation Rubric half‐sheet.”

6 cups of the same type of soil,

2 cup of each: sandy soil, silt soil, and clay soil,

4 soil samples from areas around school (playground, front school yard, by the lake, and in the forest), and

2 soil samples of potting soil At each station:

2 hand lens,

soil sample,

empty cup

water dropper,

250 mL of water in beaker, and

teaspoon III. Lesson:

a. Warm Up Think, Pair, Share: A list of variables that affect the growth of plants. Each pair will share out one variable and the ideas will be recorded on the dry erase board. Define biotic and abiotic in a T‐chart on the on the chart paper. Call on students to categorize each variable from the dry erase board as biotic or abiotic. Then tell students that of the variables listed, we will focus on those related to soil.

b. Focus on Soil 1. Give each student a copy of the Soil Observation – Day 1 sheet.

2. Students will go to their first station. As a class, use a common soil sample and the Key to Soil Texture by Feel Key to identify the soil sample texture.

3. Preview the notes sheet and the information they will record in their soil observations. Students will rotate through three stations, so they can experience a sand soil, clay soil, and silt soil. 10 minutes per station.

4. After students complete the rotations, they will return to their assigned seats for a summary.

c. Closure Students will answer the following questions as a formative assessment. 1. What soil characteristics did you observe? 2. How did the soils differ from each other? 3. Which sample(s) was/were sand, silt or clay? 4. In what ways does a dichotomous key help you analyze soil texture? 5. Based on your experiences so far, how do you think soil affects the growth of plants? 6. About what are you wondering?

Lesson 2: Objective: Students will observe different soil samples on site and make connections between the environment and the contents of the soil. Students will practice identifying the texture of soil samples.






S.IA.06.13 Communicate and defend findings of observations and investigations using evidence. I. Preparation:

Get permission to dig in three different sites on school grounds.

Bring shovel

Prepare trays with group materials Teacher Notes: The chemical reactions in water‐bearing soils cause color changes, and soil color can therefore be used as an indicator of the frequency and duration of wetness. In many cases, human products (e.g., litter, chemical pollutants) enter a wetland just as deposited soil and other natural materials do—with the inflow of water. These materials are introduced to the environment at some point, whether intentionally or unintentionally.

II. Materials Needed:

Copies of “Day 2 Soil Observations”

½ cup measuring cup

Pitchers that hold 2 cups of water.

For each group:

Jars with lids

Small plastic bag,

Trowel or shovel,

Toothpicks,

White paper plate,

Hand lens,

Jar with lid, and

Water

III Lesson (Day 1) a. Warm‐Up – Think and Share with Pair

What were different characteristics of soil that we observed yesterday? What were some ways soils would affect plant growth?

b. Visit to Soil Sites

Tell students that they will work as a team to analyze a soil sample and that each group will collect a sample of soil (at least ½ cup). We will walk to the sites together so you can see each site.

c. Hand out “Soil Observations on Site – Day 2” to each student. Hand out bags and digging tools to

each team. Collect soil samples at the playground, the front yard of the school, near the lake, at the edge of the forest and in the forest.

d. Observations back in the Classroom

1. On the team desk: Students need 1 “Key to Soil Texture by Feel,” 1 “Observation Rubric – half‐sheet”, a copy of the student sheet for each person,

2 magnifiers, 2 toothpicks, 1 jar, 1 paper plate.

2. Back at the room, teams will transfer their soil to a white paper plate. Have students use a toothpick and a hand lens to examine their soil and to sort the soil particles into different materials. Have them answer questions 1 and 2 on the first student page.

3. Students make a “soil shake” by placing ½ cup of their soil into a jar with a lid and add about 2 cups of water. Ask them to predict what will happen if they shake the closed jar and let it settle for a while (first student page, question 3, part 1).

4. Students close the lid and shake the jar hard for a couple of minutes. Students will label their jar and place in out the counter until tomorrow’s observations.

Lesson (Day 2): Objective: Students observe the layers that have formed in each jar. Since larger components settle out first, the soil particles will fall out in layers. Pebbles will fall first, then sand, silt and clay; and then organic materials (leaves, twigs and stems) will float or be suspended in the water.







a. Students observe and record their observations. Students create a scientific drawing of the layers

formed by their sample (first student page, question 3, part 5. b. Students present their observations and drawings to the class.

c. Class discussion/assessment: 1. What did you find or see in your soil shakes? 2. Did you find anything that was natural (not human made) in the soil? If so, how do you

think it got there? 3. Based on your observations of real field soil samples, what is soil made of? What evidence

do you have? 4. Did you find anything that was not natural (i.e., human‐made) in the soil? If so, how do you

think it got there? 5. Describe the differences in the soil shakes.

6. Why do you think these differences occur? c. Student journal writing/assessment: 1. What is soil made of? 2. How can soils be different from each other?

3. How do the differences in soil affect plants growing in the soil? 4. What are you wondering?

d. Extension: Determine the percent composition of your soil shake. Use rulers to measure the height in the jar for each type of particle. Create ratios and percentages. Include this information in your detailed observations. Write a summary comparing the percentages of two different soil types.

e. Extension: Go back to the site and have students look for evidence that shows where the soil particles came from? Most organic topsoil is the result of the breakdown of fallen leaves and dead plants, as described in “Nature’s Recyclers” in Project Learning Tree. Organic wetland soil is the accumulation of organic material that has not decayed because of the anaerobic soil condition. Mineral soils are formed over time from weathering of rocks. Wetland soils on the banks of streams and rivers may have been formed through the gradual deposition of soil particles that were carried in (and eroded) by water.

f. Extension: Can you tell where the water and soils in this area are coming from? What watershed

drains to this spot? Have the students look at factors that bring water into the area, since it is the degree of wetness and how it affects the condition of the soil that we are most interested in here. Look at topographic features of the area and weather conditions. For example, if the wetland lies in a depression at the bottom of a slope, runoff from the slope will end up in the wetland, eventually seeping into the soil to make or keep it wet.

g. Optional Activity: Make Your Own Soil Color Chart (Do You Dig Wetland Soil? WOW!: The Wonders

of Wetlands, The Watercourse and Environmental Concern Inc. 1995, pp. 231‐ 238) h. Optional Activity: Observations of Soil Profile (Do You Dig Wetland Soil? WOW!: The Wonders of

Wetlands, The Watercourse and Environmental Concern Inc. 1995, pp. 231‐ 238)

Soil Observations Name __________________________________

Day 1 Record your observations for each soil sample. Use the rubric for detailed observations to guide your work.

Sample 1

Sample 2

Sample 3

Day 2 Soil Observations Name ____________________________________

School Soil Sample 1



Key to Soil Texture by Feel Begin at the place marked “Start” and follow the flow chart by answering the questions, until you identify the soil sample.

Observation Rubric Name __________________________ Date: __________

Category 3 2 1

Completeness All entries are completed.

All but a few entries are

completed.

More than a few entries are

incomplete.

Clarity Observations include at least 5 of

the following details:

Color

Shape

Size

Amount

Texture

Scientific drawing.

Observations include 4 of the

following details:

Color

Shape

Size

Amount

Texture

Scientific drawing

Observations include 3 or

less of the following details:

Color

Shape

Size

Amount

Texture

Scientific drawing

Accuracy – Labels Drawings are accurately labeled

with straight line segments

Drawings are partially labeled

or with curved lines

Drawings are not labeled

Accuracy – Drawing Drawing matches what the item

looks like.

Drawing is a stereotyped

drawing of the item.

No drawings are made.

Accuracy –

Measurements

Specific measurements are

recorded.

General descriptions, such as

“long” or “big” are used.

No description of size is

recorded.

Lesson 3 Objective: In lesson 4, students will create a terrarium to study how soil type affects plant growth. In this lesson, students will share their hypotheses for how plant growth is affected by different soils. Students will share their wonderings about soil and plant growth. Student groups will choose their soil type for building their terrarium.





S.IA.06.12 Evaluate data, claims, and personal knowledge through collaborative science discourse. 1. Materials Needed:

2 pieces of chart paper per group 1 set of markers per group

2. Lesson:

a. Warm‐Up/discussion: 1. What is soil made of? 2. Describe the texture of sandy soil, silt soil, and clay soil. Craft an explanation of soil using student ideas. Students record this in their science glossaries. Verify student understanding of classifying soil by texture.

b. Assign group roles: recorder, speaker, president, materials manager. Students will need their science journal answers and notes from the last two days.

c. Materials manager gets markers and two pieces of chart paper. Recorder titles one chart paper “Wonderings” and the other chart paper “How Soil Affects Plants.” President makes sure each group member shares their ideas for how soil affects plants and the recorder documents the ideas. President makes sure each group member shares their wonderings from the last two days. Materials person posts wonderings in the back of the room and how soil affects plants in the front of the room.

d. Speakers take turns sharing their ideas about how soil affects plants. e. Explain to students that they are going to build terrariums using different types of soil and

investigate how the soil affects plant growth. f. In your group, rate your choices of soil type from 1 to 5, 1 being your first choice.

The choices are potting soil, playground soil, front school yard soil, soil from by the lake, deciduous forest soil. There will be three groups for each soil type.

g. After a few minutes, draw sticks to determine who gets which soil type. h. Class discussion: (Journal and partner share)

Why do you think I’m having three groups use the same soil for this investigation?

Lesson 4 Objective: Students will create the terrarium for their group. This lesson is the Science and Technology for Children, Ecosystems Unit, Lesson #2.




Lesson: I. See lesson plan, “Setting up the Terrarium.”

Follow the lesson with the following alterations: Materials: 2 cups of each type of soil per student group Procedure: Skip #1. Final Activities: Skip #2 and #3 Final Activities: With #4, hand out the rubric for detailed observations and review the targets for their recordings.

II. Student Journal due at the end of the class:

Now that you have made your terrarium and recorded your initial observations, think about the information you would need in order to see how soil affects plants. What information do you want to know from other groups so you can determine how different soil affects different plants? What measurements would you want students to carefully record? What observations would you want students to carefully record?

III. For the next lessons: Read students’ ticket outs and create an excel document for data collection. For example, last year, students wanted to measure the height of the plants and the number of plants that germinated. See example of data sheet, “Terrarium Data.” Create a new data sheet based on student ideas.

Terrarium Data

Date # of Dropperfuls of

water

# of Mustard plants

# of Grass plants

# of Alfalfa plants

Height of tallest plant

Which plant was tallest

IV. Optional lesson: control versus experimental variables Lessons between Lesson 4 and Lesson 5 Lesson 4.1: Three times a week for two weeks, students will make observations and record the data on a data table. During the two non‐observation days, students will share out their results in class discussions and work on their assessment. Lesson 4.2: Students will finalize their results for #1‐3 on the assessment and each group will create a poster for each assessment question #1‐3 that displays their results. Lesson 4.3: Students meet in groups based on soil type to compare data, discuss their analysis of the data, and complete assessment question #4. Lesson 4.4:

Students meet with a group who used a different soil type. Students analyze the data and discuss their results, and complete assessment question #5. Assessment question #6 is due for homework. Objectives for lessons 4.1 – 4.4


S.IP.06.15 Construct charts and graphs from data and observations.

S.IP.06.16 Identify patterns in data.




S.IA.06.14 Draw conclusions from sets of data from multiple trials of a scientific investigation.

S.IA.06.15 Use multiple sources of information to evaluate strengths and weaknesses of claims, arguments, or data.

A.RP.06.08 Understand that relationships between quantities can be suggested by graphs and tables.

Assessment: Results of Plant Growth in Different Types of Soil 1. Germination Data:

Create a coordinate graph representing the # of seed that germinated over the two week time. Let the independent variable be the # of days since the seeds were planted. Use green to represent the grass data, let red to represent the mustard data, and let yellow represent the alfalfa data.

Write a paragraph that describes how the change in germination over time. 2. Which seed did better?

Is there a seed type that had better growth than others in your investigation? In your answer, please include:

The percent of seeds that germinated (for each type of seed),

Details from your observation notes about the health of the plants over time (height, color, etc.), and

Possible explanations for why one seed did better than others. 3. Height Data: Create a coordinate graph representing the growth of the tallest plant per type over the two week time.

Let the independent variable be the # of days since the seeds were planted. Use green to represent the height of the tallest grass plant, let red represent the height of the tallest mustard plant and let yellow represent the height of the tallest alfalfa plant.

Write a paragraph that describes how the height of the plants changed over time. 4. Two other groups completed this investigation with the same soil type as your group. How does this soil

type affect plant growth? What evidence supports your answers? What conclusions can be made from all three sets of data? What questions arise as you compare the three sets of data?

5. Study the germination data and height data for one other soil type. Compare and contrast the effect soil

type has on plant growth. What evidence supports your answers? What questions arise as you compare the data from different soils?

6. Choose one of the prompts to answer.

a. What other variables besides soil seem to affect plant growth? What evidence do you have? b. Before the investigation, we brainstormed a list of ways that soil affects plant growth. Choose one

idea from that list and describe how you could investigate or test that idea.

Lesson 5: Objective: Students will explore how variations in water, light and temperature affect plant growth. Students will describe how precipitation and geography can affect the plant and animal species that are found in a particular region.

6 – G3.2.1 Explain how and why ecosystems differ as a consequence of differences in latitude, elevation, and human activities (e.g., South America’s location relative to the equator, effects of elevations on temperature and growing season, proximity to bodies of water and the effects on temperature and rainfall, effects of annual flooding on vegetation along river flood plains such as the Amazon).




S.IA.06.13 Communicate and defend findings of observations and investigations using evidence. I. Lesson:

This lesson is called “Rain Reasons” and is found in the Project Learning Tree book, page 123‐129. Complete Part B, #1 and 2 and Part C, #1, 2, and 3.

II. Class discussion: What connections can you make between what you are learning in social studies and what you are learning in science? What are abiotic factors? List examples of abiotic factors. Based on this assignment, what evidence do you have that rainfall affects plant growth? Based on this assignment, what evidence do you have that sunlight affects plant growth? Based on this assignment, what evidence do you have that temperature affects plant growth? How do you think plant growth and type affect other living things?

III. Student Journal Reflection/Assessment: How do abiotic factors affect biotic factors in an ecosystem? Justify your answer with evidence from this unit.

biotic factors forest unit-kellie · pdf filein this unit, students will study how abiotic...

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