Counting Cars
Lab
Calculating Diversity Using the
Shannon-Weiner Index
Learning Objectives for this
Lesson
 Learning Goals for the Diversity Unit
 Minds ON clip: Carl Sagan
 Yesterday’s Recap
 Calculating Diversity: Shannon Index
 Counting Cars Lab: instructions and lab
safety
 Conclusion: wrap up
Learning Goals for Biodiversity Unit
We are / will be learning to…
 Analyse the risks and benefits of human intervention (e.g. pesticide
use, fish stocking, tree planting, etc.)
 Analyse how climate change could impact the diversity of living things
(e.g. Global warming, increase in precipitation)
 Become familiar with terms such as: species diversity, structural
diversity, bacteria, fungi, binomial nomenclature, morphology
 Classify, apply, and draw dichotomous keys to identify and classify
organisms according to kingdom
 Explain concepts of taxonomic rank such as genus, species and taxon
 Compare/contrast characteristics of prokaryotes, eukaryotes and
viruses
 Compare/contrast anatomical and physiological characteristics of
organisms representative of each kingdom
 Explain structural and functional changes of organisms as they have
evolved over time
 Explain why biodiversity is important for maintaining viable
ecosystems
MINDS ON!
Carl Sagan’s “Pale Blue Dot”
http://www.youtube.com/watch?v=p86BPM1GV8M
A Quick Recap From
Yesterday…
Biodiversity: The variety and number of a
species in an ecosystem. It can refer to the
variation between individuals within a
species.
Biodiversity within an ecosystem can be
affected by a number of factors (e.g.
invasive species, resource abundance,
competition between species and within a
species, reproduction, disease, etc.)
Resources: Biology 11, Addison-Wesley, Toronto 2002.
Calculating Diversity: The
Shannon Index
Biodiversity (species diversity) can be measured
using the Shannon Index.
Shannon Index
Number of individuals of species “i”
P𝑖 =
𝑛𝑖
𝑁
𝑆
H`=
𝑝𝑖(ln 𝑝𝑖 )
Total number of species
𝑖=1
(Equation 1)
(Equation 2)
Number of species
Relative abundance of species
You will need a
scientific calculator
for this.
Counting Cars Lab
This lab involves going outside to count cars,
determine the diversity of the types and numbers of
different vehicle makes (NOT models)and to calculate
the diversity found. You will be asked to predict,
hypothesize, calculate, and communicate those
results.
Please note: This is not a formal lab write up;
however, it will be marked. Be sure to:
1. complete the pre-lab questions, 2. fill in the tables,
3. complete the calculations to determine the
diversity and 4. answer the questions in full
sentences.
LAB SAFETY
We will be going outside, so please
remember safety:
1. Do not leave the grounds of the school
2. Stay within the group you have been
assigned
3. Use extreme caution in the parking lot
when moving around vehicles and be
watchful for vehicles moving.
4. Use common sense: wear a coat!
5. If in doubt about anything, ask us!
How to Calculate the Shannon Diversity Index
1. Find the number of a specific species in a population (ni).
2. Divide the number of a species you are looking at by the number in the
population (N) to calculate the relative abundance (pi). In the tide pool example,
22 sea anemones divided by 58 equals 0.38. Once you do this for each species,
the sum total of all your abundances should be 1.0. Make adjustments as
necessary.
3. Calculate the natural log of the relative abundance. Log calculations are easiest
on a calculator using the Ln button. The Ln of 0.38 equals -0.97. Don’t worry
about the negative, but it needs to stay!
4. Multiply the relative abundance by the natural log (ln) of the relative abundance.
This should fill the last column of your chart. In the example, -0.97 times 0.38
equals -0.37.
5. Repeat these steps for each species (car maker) you found in the sampling.
Feel free to divide up the work between group members.
6. At the bottom of each column is a “total” row. Find the sum of each value in the
column and fill it in. We are interested in the total of the last column, which is the
sum of the abundance and natural log of the abundance of each species.
7. Multiply the total of the last column by -1. This is H'. Notice you are only getting
rid of the negative!
8. This number is the Shannon diversity index for this ecosystem (parking lot).
Wrap Up!
Exit Card:
Imagine that a new insecticide has
been used in a garden that has
mistakenly killed many of the bees
that are able to visit this garden.
What are some of the implications
that this could have on the diversity of
plants living in the garden? Explain.