Class 3 – Go with the Flow – How Trees Help Our Cities

Objectives

By the end of the lesson, students should be able to:

• Explain what a combined sewer overflow (CSO) is and describe how it impacts local waterways and communities.
• Demonstrate understanding of how trees manage stormwater through processes like interception and evapotranspiration.
• Identify and compare three common street tree species in Holyoke and their adaptations for urban environments.
• Create a watercolor art piece that visually represents how water moves through trees and into the environment.
• Reflect on how urban trees contribute to environmental justice and community well-being.

NGS Curricular Standards:

• LS4.D: Biodiversity and Humans: Changes in biodiversity can influence humans’ resources, such as food, energy, and medicines, as well as ecosystem services that humans rely on—for example, water purification and recycling. 

ASPB Principles:

• Ecosystems – Impact of Biodiversity – Plants are key to maintaining complex natural systems. High biodiversity ensures greater ecological resilience in the face of ecological changes. Human activities can impact biodiversity which can further impact ecosystem health and associated ecosystem services
• Ecosystems – Ecosystem Services – Plants provide many supporting, provisioning, regulatory and cultural ecosystem services. For example, plants provide food, fiber, and medicines. Plants also play important roles in regulating global climate.

Materials and Preparation

Art Materials 

• Watercolors 
• Micron Pens
• Brushes
• Watercolor Paper
• Paint Palettes
• Honeylocust, Pin Oak, and Littleleaf Linden Leaves
• Cups/Jars
• Paper Towels
• Pencils

Other Materials

• Laptop

Class Summary

Instructors began class with a round of introductions, where students shared their names and pronouns (if comfortable). Students were reminded that their participation in the lesson would be rewarded with a sticker, in order to up student engagement. For this week’s ice-breaker, students played “this or that,” where after given a prompt (ex: do you like rainy days or sunny days), students moved to the side of the classroom corresponding with their choice.

Teachers then spent 20-30 minutes to go through the week’s science concepts, explaining with a mixture of the lecture slides and student participatory activities, including a movement activity, where students played “be the tree,” to simulate the experience of water intake and evapotranspiration on urban trees. The slideshow ended with identification of local species, such as honeylocust, pin oak and little-leaf linden. For the art activity, students used watercolors to paint local leaves from observation, with this medium aiding in understanding of interior water mechanisms within the leaf. Class ended with students reflecting on this week’s prompt in their journals.

Lecture Slides

Art Activity

This week, students used real leaves from local species to practice painting from observation. The medium of watercolors allowed them to notice how water flows on the paper, and over their painted leaves, solidifying what they have learned about water movement through the entire tree, and what this means for maintaining the health of the urban forest.

Instructions: 

1. Start with quick watercolor demo to show techniques
2. Have students trace or sketch one of the three street tree leaves 
3. Using watercolor paints, let them explore how the paint flows, spreads, and blends — just like water moving through soil and trees.
4. Once dry, add details with fine-tip ink pens

• Tree name
• One fact about the tree
• One way it helps with stormwater management

Students can also paint raindrops, roots, or flow lines to show water movement.

If time, repeat the same process with another leaf!

Student Art: 

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Assessment and Reflections

How can planting more trees help make all neighborhoods healthier and fairer places to live?

Instructor Notes