Lab Week 6

The first site of the experiment was the grassland at York University’s Keele campus beside the Pond road. An adult maple tree was randomly selected in the middle of the grassland which was the warmest part of the area. To have been considered an adult tree, the maple tree had to be twice the height of one consistent student, which was about 3.4 metres. The percent open space of the tree (the amount of light the tree received), was found by one student consistently forming a rectangle with the index finger and thumb of both hands joint together. The student would raise this rectangle until it was at the top of the tree where the sun hit the leaves. The approximate measure of their rectangle that was not covered by leaves was recorded as the percent open space. A leaf was then removed from the tree. The length of the leaf from the part where the stem attached to the leaf (but not including the stem length) to the top of the leaf was measured with a ruler in centimeters and recorded. This was repeated two more times for two new leaves from the tree. To measure for density (competition), the distance to the nearest three adult trees of any species was measured with a transect in metres and recorded. This entire procedure of finding a random tree, measuring the amount of light the tree receives and density of trees in the area was repeated for twenty trees (sample size) in the grassland. This was then repeated for twenty trees in the centre of the forest as it was the coolest part of the forest. The total sample size, for both the grassland and forest, was 40 trees.