In this activity (located on page 2 of the PDF), learners will identify a group of deciduous trees to study. Once the species has been recorded, the circumference of the trunks will be measured at the same spot on each tree, as well as the height of the lowest branch. Then learners will calculate the diameter and analyze the result to look for a relationship between tree diameter and height of the lowest branch. This activity exposes learners to techniques that foresters actually use to study and measure trees. Relates to the linked video, DragonflyTV GPS: Temperate Rain Forest.