Trees can reduce ground and air temperatures by providing shade due to large canopies and releasing moisture during transpiration.

.

Students observe that during the late spring months the temperature on the playground becomes extremely hot causing uncomfortable conditions and extremely hot play structures.  They wonder how they could improve the conditions on the playground during the late spring months.

Outdoor Field Experience — The Playground

Ask students to think about a time they go out to play in the schoolyard that they experienced a feeling of being way too hot.  Ask them to write or draw about their experiences. Share with a partner or with the class what experiences they have had while playing on the school’s playground when it is hot outside.

Ask them the following question:  Is this a problem and why? (Tip : This is the issue they will be investigating)

Inform students that they are going to be working for the next several weeks to find a solution to a problem occurring on the playground during the warmer months that is sometimes causing students to become ill and/ or injured.  Select volunteers to guess what the problem could be and then share that the issue is “high temperatures.”  

Students working in groups of 3 or 4 will go out into the playground .

Have students stand in a sunny spot, and record how they feel. Then stand in a shady spot and record how they feel. Describe not only how you feel but what you see, hear, and smell. 

Now ask them to draw on graph paper the layout of the playground that includes the location of playground equipment, playing fields, tree location and foliage, benches, gates, etc.  (Students in the 8th grade and 7th grade could create a scale drawing of the playground.) Remind them that this is a birds-eye view like you would see on Google maps. You can even print out a google map for reference, but have them use the graph paper and draw themselves.

Students will be looking a the air and surface temperature at five different locations. Make sure they mark their maps and number the locations. Provide each group with thermometers to record the temperature of four different pieces of playground equipment and the ground under them plus the temperature of one additional location.  Students should record the temperatures and conditions  on their drawings at each specific location. Example: 87 F and metal is reflecting the sun’s rays;  85 F heat waves can be seen coming off the playground surface.

After students identify the conditions on the playground, come inside to have students share and record their data. Discuss why there may be some differentiation in the data recorded and how taking an average class number may help them to create once class schoolyard  map with the average class readings for all locations recorded.

Did the temperature numbers align with how they feel at each location?  (this may be a good time to bring up the notion of a heat index)

Discuss in their groups why they think any or all locations on the playground are examples of extreme heat.   Are there places they could/do goin the playground to cool off?

Reconvene as a class and have students share out.  Record student responses on chart paper or smartboard.  Possible responses:  I stand in the shaded areas around the playground, I sit in the grass, I lean against the building.

If there are multiple locations identified for cooling areas, repeat this activity and add in the temperature of those areas as well so now you have a good “map” of schoolyard temperatures and cause and effect on a given day.

Have students do a Think-Pair- Share to answer the question “What could be done to provide cooler areas on the playground?”  Groups should record their  ideas on a brainstorming sheet. Have groups share their ideas.

Compare to other schoolyard

Provide students with images of a playground with plenty of trees that provide shade coverage.  Ask students to record their observations about the trees in picture.  Ask, What are the characteristics of the trees that make them beneficial?  Record student responses. 

After making observations,  have students research the types of trees that are in the playground.  Have them record characteristics of the trees they feel are important for trees to help to reduce high temperatures.  Ask, “ What characteristics for trees are important to pay attention to when choosing trees to help reduce high playground temperatures?”

Working with a partner, students will be given two VENN diagrams to compare and contrast a playground that is similar to their school’s playground or environment and one playground  or environment that is different (has trees providing shade).

Ask students “What do they notice about the playgrounds or environments?”  Students should complete the Venn diagrams for both playgrounds or environments.

After comparing the playgrounds, provide the students with temperature data for playgrounds with trees and without.  Have students analyze the data and record their findings.  Have students draw conclusions about why the temperatures are different for the two playgrounds?

Have students compare data from their playground to the data of the playground with trees.  Have students draw conclusions about why the temperatures are different?  Students should come to the conclusion that their playground lacks trees or needs more trees

Seasonal mapping

Continue to map the temperature in your schoolyard over days or weeks and in various weather conditions to develop a deeper understanding of seasonal shifts.  Map the placement of the sun in the sky over time.  Graph your results and review  trend lines during one season

Our Community

Do we have trees in our community? What are they and what are their benefits ?

Making the case for more trees requires students to first know  the characteristics and benefits of trees in their local environment.

Provide students with Tree Identification guides or a Tree Id App.  in order for them to identify the trees in the community. (iTree app) 

Explore the composition of the soil is sandy, clay, rock, loamy, acidic, alkaline (we can have them do the test) 

Students should use tree identification information to explain why certain trees should be planted in the school playground.  Students should provide the facts about the trees to explain why the selected trees should be used to reduce the temperature in the playground. How to choose the right tree for your neighborhood

Question: What criteria is used to determine the selection of trees? Possible student input and agency input 

Need a simplified tree identification guide that students can easily follow

Have students choose at least two or three trees, describe its characteristics, and have students determine why based on the information provided whether or not the tree would work.

Creating Favorable Conditions 

Ask students “What do plants need in order to grow?”  Record the students’ answers on chart paper on the smart board.  Give  each student a picture showing how water travels through a plant.  Have them trace the pathway water takes from the ground through the roots, stem, and leaves (xylem and water out the (stomata).  

Explain that water is pulled through plants when water evaporates through the stomata on leaves. Tell students that the loss of water through leaves is called transpiration.  Tell students that water will be collected from the leaves on a plant.  Select a plant with medium size leaves.  Place a clear plastic bag around some of the leaves and close the bag with a twist tie.  Place the plant near a window with bright light or under a grow light for 45 – 60 minutes.  After about 60 minutes, condensation will collect on the sides of the bag.

Ask students “Does water help reduce temperatures? “  discuss answers.  Have students place two thermometers under a light and record the temperature.  After the temperatures are recorded. Mist one thermometer with water and leave the other thermometer dry and record the temperature for each thermometer after one or two minute(s).  Students should write a conclusion about what they discovered about temperatures and moisture.

Students will read about the urban heat island effect and the Philly Tree Plan’s goals to increase tree canopy in certain areas of Philadelphia.  What can be done to help lessen its impact on people in the cities. What action can they take in their own schoolyard? 

Advocate for planting some trees in their schoolyard using the new knowledge they have of their benefits to their school community.