Measuring Biodiversity Lab

Biodiversity can be defined simply as the variety of life. However, biodiversity can be studied at many levels, including genetic diversity, species diversity, and ecosystem diversity. High biodiversity is an indicator of ecological resilience, or the ability of an ecosystem to resist change or recover from disturbances. Scientists can calculate the biodiversity index of an ecosystem using a simple formula. The closer the biodiversity index is to 1, the higher the biodiversity of the ecosystem is.

- Species richness [tex]$(S)$[/tex] is the total number of species in an ecosystem. Richness does not take into account the number of individuals, proportion, or distribution of each species within the ecosystem. The larger the sample, the more species we would expect to find.
- Species richness alone misses an important component of species diversity: Species abundance (number of individuals) of some species may be rare while others may be common.

[tex]\[ \text{Biodiversity Index} = \frac{\text{species richness}}{\text{species abundance}} \][/tex]

Pre-Lab Sample:

A forest has many different species of both plants and animals. You decide to leave a wildlife camera (designed to take a picture when something moves) in the forest for a day to measure the biodiversity. Your data is listed below.

\begin{tabular}{|l|l|l|l|l|l|}
\hline
White-tailed deer - 14 & Fox Squirrel - 11 & Rabbit - 8 & Eastern toad - 6 & Red fox - 2 & Towhee - 1 \\
\hline
Porcupine - 2 & Chipmunk - 6 & Skunk - 2 & Eastern box turtle - 3 & Barred Owl - 2 & Eastern phoebe - 2 \\
\hline
Black Bear - 1 & Opossum - 2 & Mouse - 4 & Cooper's Hawk - 1 & Raccoon - 4 & Cardinal - 5 \\
\hline
\end{tabular}

Questions:

1. Species Richness: [tex]$\qquad$[/tex]
2. Species Abundance: [tex]$\qquad$[/tex]
3. Biodiversity Index: [tex]$\qquad$[/tex]

- How diverse would you consider this ecosystem?
- What would you consider to be a major downfall to this sample?



Answer :

To analyze the biodiversity of the ecosystem in the forest from the data provided, we need to calculate the species richness, species abundance, and biodiversity index. Here's how we proceed step by step:

### Step-by-Step Solution

1. Calculate Species Richness:
- Species richness is the total number of different species in the dataset.
- From the data table, we count the number of unique species.

Unique species:
1. White-tailed deer
2. Fox Squirrel
3. Rabbit
4. Eastern toad
5. Red fox
6. Towhee
7. Porcupine
8. Chipmunk
9. Skunk
10. Eastern box turtle
11. Barred Owl
12. Eastern phoebe
13. Black Bear
14. Opossum
15. Mouse
16. Cooper's Hawk
17. Raccoon
18. Cardinal

- Species Richness (S) = 18

2. Calculate Species Abundance:
- Species abundance is the total number of individuals of all species combined.
- We sum up the individual counts of all species from the table.

Individual counts:
- White-tailed deer = 14
- Fox Squirrel = 11
- Rabbit = 8
- Eastern toad = 6
- Red fox = 2
- Towhee = 1
- Porcupine = 2
- Chipmunk = 6
- Skunk = 2
- Eastern box turtle = 3
- Barred Owl = 2
- Eastern phoebe = 2
- Black Bear = 1
- Opossum = 2
- Mouse = 4
- Cooper's Hawk = 1
- Raccoon = 4
- Cardinal = 5

Adding these together:
14 + 11 + 8 + 6 + 2 + 1 + 2 + 6 + 2 + 3 + 2 + 2 + 1 + 2 + 4 + 1 + 4 + 5 = 76

- Species Abundance = 76

3. Calculate Biodiversity Index:
- The Biodiversity Index is given by the formula:

[tex]\[ \text{Biodiversity Index} = \frac{\text{Species Richness}}{\text{Species Abundance}} \][/tex]

Substituting in the values we calculated:

[tex]\[ \text{Biodiversity Index} = \frac{18}{76} \approx 0.2368 \][/tex]

### Results
- Species Richness: 18
- Species Abundance: 76
- Biodiversity Index: 0.2368

### Interpretation
- Diversity of the Ecosystem:
- The biodiversity index of approximately 0.2368 suggests a moderate level of biodiversity. The closer the index is to 1, the higher the diversity. In this case, since the value is less than 0.5, it indicates that while there is a variety of species, the overall distribution of individuals is slightly dominated by a few species (i.e., some species have much larger populations than others).

- Major Downfall of this Sample:
- One major downfall is that the sample may not be comprehensive enough. The number of individuals of each species might be skewed due to factors like the camera's placement, the time of day it was operational, or even the visibility and behavior of certain animals. Additionally, the sample size (only a single day of observation from one camera) might not capture the true representation of the ecosystem's biodiversity. Ideally, a more extended observation period with multiple devices would provide a more accurate assessment.