Witton Middle School

# Science

## LO: Explore trees

1. Try this quiz. Tick all 3 boxes: Leaves, Twigs and Fruits. Then click play.
2. Can you now complete the e-worksheet?

Find 5 trees in open spaces. You will need a tape measure and might want a calculator.

1. Estimate the age of a tree

You probably know that you can count the rings on a tree stump to estimate the age of the tree when it was cut down. However, how can you estimate the age of a tree whilst it is still standing?

• Measure the circumference at a height of 1.5 m above the ground.
• Divide the circumference by:
• 1.88 for oak
• 2.50 for hazel, ash and beech
• 2.75 for sycamore
• 3.13 for pine and spruce
• If your tree is not in the list above use 2.50
• Why do you divide by different numbers?
• 2. Estimate the height of a tree
• Stand with your legs apart and your back to the tree.
• Keeping your legs straight, bend down and look at the tree between your legs.
• Move backwards or forwards so that you can just about see the top of the tree between your legs.
• Measure the distance between your feet and the tree trunk. When you can see the top of the tree between your legs, the distance between your feet and the trunk is about the same height as the tree.
• Think about how you will measure the distance between your feet and the tree. You could ask a friend to count strides or heel-to-toe steps between you and the tree trunk.
• When you can just see the top of the tree through your legs, the angle is approximately 45°. The trunk is perpendicular to the ground. Draw a diagram to convince me that this forms an isosceles triangle so that:
distance to the tree = height of the tree
• 3. Test a hypothesis
• Hypothesis: Taller trees have thicker trunks

Use the data you have collected to convince me. Remember to include data.

Possible sentence starters:

• My data supports the hypothesis because….
• There is so much scatter in my data that….
• Contrary to the hypothesis, my data shows…