CHEMISTRY IN CONTEXT
LAB 4: QUADRAT ANALYSIS, PAGE 1
CYCLE 2
NAME
DATE
Quadrat Analysis of Plant Biodiversity
An Application of Length Measurements
PRE-LAB/DISCUSSION:
Organisms of the same species that
live in the same habitat (an area with
food, water and air for the organism)
comprise a population, several
different interacting populations within
an area make up a community.
Communities interact with each other
and share the same resources. These
interrelationships, as with all
environmental interrelationships, are
permanently linked, so that what
affects a member of one population
will almost certainly affect an individual
of another population. Thus, in a given
community, the plant species or populations that exist there are connected to one
another. Living things in the environment are irrevocably linked to one another. Are
humans linked to other organisms? If so, how?
Biodiversity is a term that means the variety of living things in an area. By counting
the number of different living things in an area, we can calculate a diversity index.
Today, you will be doing a field lab (outdoors) that involves quadrat sampling to
determine biodiversity. A quadrat is a BIG square with smaller squares inside of it. The
big square has already been marked off for you near the stream on campus. Your job
will be to randomly select a spot where you will mark off a smaller square. While the big
square is 10m x 10m, your smaller square inside the big square will only be 0.5m x 0.5
m. If a square has four sides, all equal, how much string will you need for the perimeter
of the quadrat square that you will create?
Some important safety reminders:
1)
You will NOT be using any chemicals today, BUT you will be traveling with
four large spikes. These should be carried like scissors with your hand
covering the sharp end, and DO NOT run with them.
2)
You will NOT need your eye wear today, BUT you should wear your lab coats
to protect your dress-up clothes.
CHEMISTRY IN CONTEXT
LAB 4: QUADRAT ANALYSIS, PAGE 2
CYCLE 2
NAME
DATE
APPARATUS/MATERIALS:
4 20cm galvanized spikes
enough string to create a square with 0.5cm sides
scissors (community resource)
metric ruler OR meter stick
clipboard
PROCEDURE:
1)
Cut enough string (maybe a LITTLE bit over the total amount that you need)
to create a perimeter for a square with 0.5cm sides.
2)
Go outside to the 10m square quadrat side. Stand outside of the square
facing AWAY from the square and toss a small object OVER your shoulder
into the square.
3)
Turn around and carefully step over the string. Locate the object that you
tossed. This spot will be the CENTER of your square. Use your ruler OR
meter stick, spikes, and string to create a square with 4 0.5cm sides.
4)
In your DATA/OBSERVATIONS section describe the habitat at the site of the
LARGE square. What water source is close by? What types of life exist
here? Are there different “levels” (heights) to the habitat? On the picture of
the square in your DATA/OBSERVATIONS section, draw a picture of where
YOUR square is inside the square. Label any trees as circles and label the
location of the stream.
5)
Squatting beside your square, count the number of different plant species in
your square. (NOTE: Count the number of DIFFERENT plants not all the
plants of one type.) Then, divide this number by the AREA of your square.
This will be our diversity index for your given area.
6)
Use your ruler to measure the height of the TALLEST piece of vegetation in
your area. If you have a tree, estimate its height (25m? 50m? 100m?)
7)
When complete, remove your spikes and string and return to the classroom.
Discard your string in the trash and replace your spikes in the storage tub.
8)
Select ONE other lab group and mark the location of their square in the
quadrat picture. Record their diversity index.
CHEMISTRY IN CONTEXT
LAB 4: QUADRAT ANALYSIS, PAGE 3
CYCLE 2
NAME
DATE
DATA/OBSERVATIONS:
Description of the Quadrat:
Water Sources:
Types of Life:
Different Levels/Heights:
Location of Individual Quadrat/Visual Description of Site:
CHEMISTRY IN CONTEXT
LAB 4: QUADRAT ANALYSIS, PAGE 4
CYCLE 2
NAME
DATE
Our Square:
Number of Plant Species:
Area of the Square:
cm2
per cm2
Diversity Index (species per unit area)
Other Group’s Square:
Number of Plant Species:
Area of the Square:
Diversity Index (species per unit area)
cm2
per cm2
ANALYSIS:
1)
Who has the HIGHER plant diversity, your group or the other group? Why do
you think one is higher?
2)
It has been said that a diverse habitat will have diverse life. Why might a habitat
that is diverse be able to support MORE life?
3)
The edge effect is a phenomenon where MORE life is supporting at the edge
where two different habitats (like terrestrial/land and aquatic/water) meet. Would this be
true anywhere in our quadrat? If so, where?