Lab 2- Danby Woodlot Dataset

Site Description:

The
sampling was taken on Wednesday, September 21st, 2016 in the Danby Woodlot on
York University Keele Campus. The observations were made between 2:30-5:30pm on
a clear, sunny, summer afternoon with no wind and in 23°C weather. The woodlot
ground was covered in lots of tree sticks, dirt, fallen leaves and was mostly
shaded due to the canopy of many trees. The data was collected with my lab
partner Carrie Ewins, while the rest of the class and the teaching assistant
participated in their own lab roles in proximity.

Metadata:

Distance
to Next Tree: The first factor is distance to next tree. To collect this data we
used a transect measuring tape to measure the distance between two adult trees
along a straight path starting from the middle back of one tree, to the middle
front of the next tree.

Diameter
at Breast Height: The second factor is diameter at breast height. To collect
this data we used a measuring tape and held it up close to the selected tree’s
trunk to estimate the diameter of each tree trunk at the level of my lab partner's
breast.

Condition:
The response variable is condition. This was determined by rating the tree on a
scale ranging from 0= dead, 1= living, and 2= huge green canopy.

Methods:

A
25m transect measuring tape was used to measure the distance in cm between two
trees and recorded on a datasheet. We selected adult trees that appeared to
fall along a straight path. An adult tree had to meet the criteria of being
equal to or more than 10cm in diameter. We measured trees at my lab partner's
breast height of 153cm, which was a recorded measurement from the ground up to
the middle of her chest. We measured the diameter at breast height of each tree
by using a measuring tape. The distance from an adult tree to the next closest
adult tree along the straight path was measured from the middle of the back of
the first tree to the middle of the front of the next tree. We started by
choosing a random adult tree in the woodlot. The condition of the tree was
observed with our eyes, and was determined on a scale of 0-2, with 0 meaning
that the tree was dead, 1 meaning that the tree was living, and 2 meaning that
the tree looked like it was thriving with a full green canopy. This procedure
was repeated 9 more times to get a total of 10 replicates. We used a sample
size of 11 adult trees in total and recorded the distance from the 10th
tree to the 11th tree but didn’t record the condition or diameter at
breast height of the last tree, since the data for only 10 trees was needed.

Hypothesis:

I
hypothesize that both the distance between trees and the diameter at breast
height will have an effect on the tree's condition. This is because with increasing
distance between trees there are more nutrients available for each and there is
less of a need to compete for resources required for growth. Each tree gets a
chance to grow and spread out using as much of the nutrients available around
it without interference. A tree in good health is due to the fact that it has
the chance to use all the resources around it to grow big, tall, and with a
rich green canopy. These trees have easy access to capture sunlight, while the
trees below a full canopy are shaded and robbed from the sun. Each tree
requires enough space to thrive.

Predictions:

As
the distance between two trees increases, the condition of each tree increases.

The
greater the diameter at breast height, the worse the condition of the next
tree.