Biodiversity and Ecology for Teachers Laboratory Exam
1.Use the Shannon index to determine “H” for the following populations. Make a table to help you
tabulate the data:
A. Community A: 5 different species are evenly distributed among a community of 100 individuals. (5
points). Identify whether the community has low diversity, medium diversity or high diversity. (1 point)
Species
Number
pi
Ln(pi)
pi*Ln(pi)
-pi*Ln(pi)
A
20
0.2
-1.61
-0.322
0.322
B
20
0.2
-1.61
-0.322
0.322
C
20
0.2
-1.61
-0.322
0.322
D
20
0.2
-1.61
-0.322
0.322
E
20
0.2
-1.61
-0.322
0.322
-1.61
1.61
TOTAL
𝑆𝑆
𝐻𝐻′ = −𝑝𝑝𝑖𝑖 ln 𝑝𝑝𝑖𝑖
𝑖𝑖=1
H’= 1.61 MEDIUM DIVERSITY
B. Community B: 6 species are found in a community of 100. Four species are represented by 5 individuals.
The remaining two species are evenly divided among the remaining population. (5 points) Identify
whether the community has low diversity, medium diversity or high diversity. (1 point)
Species
Number
pi
Ln(pi)
pi*Ln(pi)
-pi*Ln(pi)
A
5
0.05
-2.99
-0.1495
0.1495
B
5
0.05
-2.99
-0.1495
0.1495
C
5
0.05
-2.99
-0.1495
0.1495
D
5
0.05
-2.99
-0.1495
0.1495
E
40
0.4
-0.92
-0.368
0.368
F
40
0.4
-0.92
-0.368
0.368
-1.33
1.33
TOTAL
𝑆𝑆
𝐻𝐻′ = −𝑝𝑝𝑖𝑖 ln 𝑝𝑝𝑖𝑖
𝑖𝑖=1
H’= 1.33LOW DIVERSITY
2. Calculate the Simpson’s diversity (DS) index showing the number of individuals of five land snail species
in a community. (5 points)
Species
n
A
50
B
20
C
20
D
5
E
5
TOTAL
100
n-1
n(n-1)
49
2450
19
380
19
380
4
20
4
20
TOTAL= 3250
𝐷𝐷 = Σ𝑛𝑛
𝑖𝑖(𝑛𝑛−1)
𝐷𝐷 =
𝑫𝑫 = 𝟎𝟎. 𝟑𝟑𝟑𝟑
𝐷𝐷 =
𝑁𝑁(𝑁𝑁−1)
3. Basic Statistics in Biodiversity and Ecology. Calculate the chi-square test. (3 points)
A school principal would like to know which days of the week students are most likely to be absent.
The principal expects that students will be absent equally during the 5- day school week. The principal
selects a random sample of 100 teachers asking them at which day of the week they had the highest
number of students’ absences. The observed and expected results are shown in the table below. Based
on this result, do the days for the highest number of absences occur with equal frequencies? (use a 5%
significance level)
Monday
Tuesday
Wednesday
Thursday
Friday
Observed Absences
23
16
14
19
28
Expected Absences
20
20
20
20
20