APES Carrying Capacity Lab

AP Environmental Science

Wheeler High School

Mr. Walstead

What is the effect of the type and size of oak trees on the number of squirrels that a forest can support?

Procedure:

This is a simulation lab since our campus does not have very many oak trees. Your team will be assigned an area of campus. You must name your “forest”

Assume that all trees in your forest are oak trees of a given species. You will be assigned a species.
Estimate the area of your forest (m2)
Measure the diameter of the trees at breast height to the nearest 5 centimeters. Record data in a data table.
Use an acorn production data table to determine the kilogram yield of acorns per tree. Then calculate the yield of all trees of each size in the survey. Total the production to get a total production for all trees in your area
Convert kilograms of acorns into kilocalories (kcal), a unit of energy. One kilogram of acorns will yield 4500 kcal of energy.
Calculate the number of squirrels that your area can support. Assume that a 0.5 kg squirrel needs 96 kcal/day. Use 365.25 days for one year.
After each team has completed its calculations, prepare a table that will combine all class results.
Include complete calculations in your lab notebook.

Questions

Define carrying capacity? What factors affect it?
Which team achieved the greatest carrying capacity? What factors affected the outcome?
Why was it necessary to convert kilograms to kilocalories before making the calculations?
It would be fair to predict that the carrying capacity is actually less than the teams calculated. Explain.
Is the carrying capacity greater with many small trees or a few larger ones?
As much as 25% to 50% of the diet of the black bear, raccoon, white-tailed deer, and wild turkey is made up of acorns. What would happen to the carrying capacity of your forest if any of these animals were present?
Assume the population of squirrels in your area has been stable for some time. A fire in the nearby forest occurs and the squirrels from that area move into your area. Describe what will happen to the population of squirrels. Sketch a graph of time versus the number of squirrels. Indicate on the graph when the fire occurred.

What I need to see in your lab notebook:

Date, Title & Objectives (needed for EVERY assignment)
Prediction – Which area do you think will support the most squirrels and why?
Team data – Type of tree, description of location including estimated area (sq. meters), and a name for your “forest”

- For each tree: Diameter, acorn yield & energy produced

- Total: trees, acorns yield, energy produced, squirrels able to support and average diameter

Class data – Forest names w/ tree types, # trees, average diameter & squirrels supported
Thorough answers to the questions asked.

“Wheeler Oak” acorn production

(based on average production from several species of oak)

Tree Diameter (cm) / Acorn Yield per Year
10 / 0.3
15 / 0.6
20 / 1.0
25 / 1.5
30 / 2.2
35 / 3.2
40 / 4.2
45 / 5.2
50 / 6.2
55 / 7.2
60 / 8.2
65 / 9.2

Carrying Capacity make-up lab Data:

Letter / Forest Name / Tree Types / # Trees / Avg. Diameter (cm) / # of Squirrels Supported
U / Forrest Gump / Wheeler Oak / 18 / 27.45 / 6
V / Squirrelhaven Forest / Wheeler Oak / 15 / 60.26 / 16
W / Trailer Park / Wheeler Oak / 16 / 47.7 / 12
X / Wapes Forest / Wheeler Oak / 13 / 28.5 / 3
Y / Forest of Wonders / Wheeler Oak / 10 / 28.5 / 2
Z / Fiddle Sticks / Wheeler Oak / 16 / 8.976 / 0

Group Data

Tree # / Circumference (cm)
1 / 95
2 / 140
3 / 40
4 / 35
5 / 40
6 / 40
7 / 40
8 / 180
9 / 190
10 / 150
11 / 106
12 / 125
13 / 30
14 / 45
15 / 40
16 / 55
17 / 95
18 / 100
U / V / W / X / Y / Z
U / V / W / X / Y / Z
U / V / W / X / Y / Z
U / V / W / X / Y / Z
S / S / S / S / T / T
T / T

S – Woods by batting cages

T – Cross country trail

U – Between baseball and practice fields

V – Front of school

W – Next to music building to trees near football fence

X – Sr. Drive

Y – Baseball Hill

Z - Magnet