Biodiversity and Ecosystems - Clay Pressings

Students will learn about biodiversity and ecosystems and create clay castings of leaves or seeds.

In this activity, students will get to learn about biodiversity and ecosystems as well as the energy pyramid. Students will gather leaves or seeds and create clay castings of them.

What You Need

Materials if dropping them off at schools: 

  • 1 1.5-inch square piece of air dry clay in a small plastic baggie per student
  • 1 foot of string per student
  • 1 Let's Talk Science colour-changing pencil (or a pencil that is round shaped) per student
  • Different coloured card stock papers cut into 4 different lengths (roughly 1.5 inches in diameter) for the energy pyramid - 1 of each size per student
  • 1/2 a sheet of printed animals and plants for the energy pyramid per student
  • 1 yellow paper sun (approximately 1-1.5 inches in diameter) per student

Materials if not dropping them off at the school:

  • 1 1.5 inch square piece of air dry clay or playdough per student
  • 1 foot of string or ribbon (or something to hang the clay impression) per student
  • 1 pencil (or something to roll the clay and make a hole in the clay to hang) per student
  • 1 piece of scrap paper and a writing utensil (to draw the energy pyramid) per student
  • A few small leaves, seeds, etc. gathered from outside per student

Lesson Plan:

PowerPoint:

Photos:

Safety Notes

As a Let’s Talk Science volunteer, safety must be foremost in our minds during all activities. As STEM role models, volunteers must always also model safe science practices.

Always keep in mind the following precautions:

  • Emphasize and demonstrate appropriate safety procedures throughout the presentation.
  • Be professional but have fun.
  • Keep workspaces clean to avoid tripping hazards.
  • Allergens should have been checked before reserving the kit (e.g. allergies to latex).
  • Activity Specific Safety: pick only flowers, leaves, seeds, etc. that you know are safe. If you are unsure, don’t pick the plant/flower. See the Toxic Plant sheet before picking flowers, leaves, etc. Also if you are in an area where there might be ticks, do a ‘tick check’ after.

What To Do

Energy Pyramid:

  1. Give each student 1 piece of white cardstock, 4 different sized cardstock papers for the pyramid, the 1/2 sheet of photos of animals and plants, a sun, glue and scissors.
  2. Place the cardstock slips onto the white piece of cardstock in a pyramid formation (smallest on top, largest on bottom). The sun is entering the pyramid from the bottom, so add the sun under the pyramid. You can glue these to the card stock.
  3. Using the photos, build your pyramid making sure each species is on the appropriate level. Do not glue them until you have checked your answers.
  4. Give the students a few minutes to make their energy pyramids and then run through the answers. Students can then glue them to the cardstock.

Clay Impressions:

  1. Roll out a piece of clay the size that you want. you can make one larger one or some smaller ones. Press the clay down with your hands and then use a pencil to roll it flatter and smoother, approximately 4mm thick
  2. Decide where to place your leaves and seeds on the clay.
  3. Use your pencil/roller to help press the leaves/seeds into the clay.
  4. Gently remove the leaves and seeds from the clay - you should see a good impression in the clay. If not, start over and press a little harder on the seeds when rolling.
  5. Use the straw/pencil to make a hole in the clay. Don't place it too close to the edge (leave about 1/2 cm from the edge) and leave it in until the clay is dried.
  6. Let the clay dry completely - it will take a few hours/overnight to dry.
  7. When it is dry, remove the straw/pencil, place a string through the hole and hang your clay impression. If you have some paint, you can paint it after it is dry.

Discovery

Investigate Further

If the audience is interested, feel free to discuss how humans have had an impact on our ecosystems and biodiversity.

  • Residential and commercial development
  • Overfishing and overharvesting
  • Pollution (plastics, oil spills, chemicals from factories, etc.)
  • Unsustainable forestry practices (taking too many trees, not planting new ones, etc.)
  • Agriculture
  • Introduction of invasive species
  • Mining
  • Transportation
  • Climate change

Another great topic of discussion is what we can do as humans to protect the ecosystems.

  • Bike or walk instead of using cars, public transit
  • Recycling and reusing products
  • Purchasing products with less packaging
  • Stop the use of single-use plastics

Investigate Further

If the audience is interested, feel free to discuss how humans have had an impact on our ecosystems and biodiversity.

  • Residential and commercial development
  • Overfishing and overharvesting
  • Pollution (plastics, oil spills, chemicals from factories, etc.)
  • Unsustainable forestry practices (taking too many trees, not planting new ones, etc.)
  • Agriculture
  • Introduction of invasive species
  • Mining
  • Transportation
  • Climate change

Another great topic of discussion is what we can do as humans to protect the ecosystems.

  • Bike or walk instead of using cars, public transit
  • Recycling and reusing products
  • Purchasing products with less packaging
  • Stop the use of single-use plastics

Resources

Lesson Plan:

PowerPoint:

Photos:

Check out additional resources (articles, career profiles and more) on these topics from Let’s Talk Science: