Your Name_____________________
Period_________
Quadrat Study
To be conducted in the field
Objectives: 1. To use the quadrat method of gathering data about the biodiversity of a habitat
2. To examine relationships between biotic and abiotic factors in three habitat types; Forest, Forest Edge, Open
We will focus on the following variables (mark each A for Abiotic or B for Biotic):
_____ Canopy cover
_____ Light
_____ Temperature
_____ Species diversity
_____ Density
_____ Natives : Non-natives
Hypothesis:
1. Start by making a broad prediction by completing the following table. Give a one to three rating to each habitat type on each
of the following measurements, 1 being the least and 3 being the greatest.
Table 1
Type of habitat
Number of
Average Light
Average Temperature % Ground Cover % Natives
Species
(Illuminations)
( ̊C)
(density)
Open space
Forest edge
Forest canopy
2.
Explain some of your reasoning about each habitat: (think of these as the “because” part of your hypothesis)
Open space:
Forest Edge:
Canopy:
3.
Next, create 2 of your own, more specific hypotheses.
a. The relationship between habitat type and one abiotic factor and one biotic factor. Example: I predict that the forest
habitat will have cooler temperatures and higher native : non-native ratio than the forest edge or open habitats
because . . . .
b.
The relationship between one abiotic factor and one biotic factor. Example: I predict that the greater the amount of
light, the greater the species diversity because . . . .
Materials:







1 m2 PVC quadrat
Thermometer
Mirror
Pencil
Picture guide to native and non-native plant species
Tape measure
Calculator (not needed in the field)
Procedure:
Note: Follow the organizational instructions about rotating between habitats. Steps can be done simultaneously by
students in the group. In order to finish in time, everyone is always working on collecting some piece of data.
1. Start at the center post of each 1/10th acre radial plot. Randomly choose three locations (trials) for your quadrat.
This is how my group decided to randomly choose the distance and direction for each quadrat location:
____________________________________________________________________________________________
____________________________________________________________________________________________
____________________________________________________________________________________________
2. Place the quadrat on the ground at the first randomly selected location. If it overlaps with another sampled location (by you or
others in your group), randomly choose a different location. If the location includes a tree or large shrub that makes it hard to
put down the white quadrat, use your tape measure to approximate the same size square. Note in your recordings if this was
done. Record noteworthy observations about this spot (examples: sloped, wet, big rock, etc.)
This is how my group decided to control placing the quadrat on the ground:
____________________________________________________________________________________________
____________________________________________________________________________________________
3. Hold your thermometer above (CV) the ground and still for 1 full minute to measure the temperature and record in Table 1.
CV: _____________________________________________
4. Use the light meter to determine the light conditions at the quadrat, or use the designations shade, filtered or sun. Record in
Table 1. If your data is numeric, be sure to include units in the column heading.
CV: _______________________________
5. Use the mirror as shown in class (arm position, etc.) to determine percent of canopy cover and record.
6. Estimate the percent of ground covered by plant life in each quadrant of your quadrat. Record in Table 2, average the four
percentages and record the average. (see NOTE below)
7. Estimate (you do not need to count individual plants) the percent of the native plant life in each quadrant of your quadrat. This
is not compared to the amount of the ground covered, but compared to the amount of non-native plant life. If you have say
30% native, this means that the majority of the plants in this quadrant are non-natives, regardless of how dense the plant growth
is. Record the percent in Table 3, average the four percentages and record the average. NOTE: In the interest of time, focus
on gathering all data while at the study site. Calculate averages AFTER you have collected ALL data.
8. Quickly examine every plant in the quadrat. Count the number of types of plants and animals present. Record the number of
species (plant and animal) in Table 1. List three plant species that you recognize, noting the most common species in that
quadrat. If you can’t identify the plants, describe the make-up of plants (ex: mostly grass, bushy large-leafed plants, ferns).
9. Repeat steps 2-8 for two more quadrat placements in the
same habitat.
10. Repeat steps 1 – 9 in the two remaining habitat sites.*
*each quadrat should be completed in approximately 20-25 minutes
Qualitative Data:
Quantitative Data:
OPEN SPACE
Table 1 Effect of Habitat Type on Biotic and Abiotic Factors—Team Data
Habitat/
Site
Letter
Quadrat
number
Observations
about location of
quadrat
Temp
o
C
Light
Canopy
Cover
%
Biodiversity
(#species)
Types of Plants
1
Open
space/
2
3
Summarize
or
Average
Table 2 Effect of Habitat Type on Density of Plant Life
Habitat
Type/Site
Open/
Density (%)
Location 1
Location 2
Average Density (%) for this Habitat
Location 3
Average for each
quadrat
Table 3 Effect of Habitat on %Native Plant Species
Habitat
Type/Site
Open/
Average for each
quadrat
Native species (%)
Location 1
Location 2
Average %Natives for this Habitat
Location 3
FOREST EDGE
Table 1 Effect of Habitat Type on Biotic and Abiotic Factors—Team Data
Habitat/
Site
Letter
Quadrat
number
Observations
about location of
quadrat
Temp
o
C
Light
Canopy
Cover
%
Biodiversity
(#species)
Types of Plants
1
2
Forest
edge/
3
Summarize
or
Average
Table 2 Effect of Habitat Type on Density of Plant Life
Habitat
Type/Site
Forest Edge/
Density (%)
Location 1
Location 2
Average Density (%) for this Habitat
Location 3
Average for each
quadrat
Table 3 Effect of Habitat on %Native Plant Species
Habitat
Type/Site
Forest Edge/
Average for each
quadrat
Native species (%)
Location 1
Location 2
Average %Natives for this Habitat
Location 3
CANOPY
Table 1 Effect of Habitat Type on Biotic and Abiotic Factors—Team Data
Habitat/
Site
Letter
Quadrat
number
Observations
about location of
quadrat
Temp
o
C
Light
Canopy
Cover
%
Biodiversity
(#species)
Types of Plants
1
Canopy/
2
3
Summarize
or
Average
Table 2 Effect of Habitat Type on Density of Plant Life
Habitat
Type/Site
Canopy/
Density (%)
Location 1
Location 2
Average Density (%) for this Habitat
Location 3
Average for each
quadrat
Table 3 Effect of Habitat on %Native Plant Species
Habitat
Type/Site
Canopy/
Average for each
quadrat
Native species (%)
Location 1
Location 2
Average %Natives for this Habitat
Location 3
BACK IN CLASS
Data Compilation:
1.
2.
3.
Calculate all averages in Table 1, Table 2, Table 3.
Transfer group data to Table 4 on Google drive.
Summarize the results shown in Table 4 in order to complete Table 5.
Table 5 CLASS DATA (USE THIS DATA TO MAKE YOUR GRAPHS)
Type of habitat
Number of
Average Light
Average Temperature
Species
(Illuminations)
( ̊C)
% Ground Cover
(density)
% Natives
Open space
Forest edge
Forest canopy
Data Analysis:
Use the data from Table 5 to create the following graphs:
Habitat Type vs. Number of Species (Biodiversity)
Habitat Type vs. Average Temperature and Light
Habitat Type vs. Density
Habitat Type vs. Native Plant Species
These will ALL be what type of graph?
Analysis Questions
After your have collected, recorded, and graphed your data using Microsoft Excel, answer the following questions using data to
support your answers:
1. How would you compare the three habitats: open space, forest edge, and canopy? Include a comparison of biodiversity as
well as other characteristics.
2. Which site supported larger plant population? Which site supported a more diverse plant population? Hypothesize why this
might be so.
3. What seems to be a meaningful indicator of biodiversity? Support your answer with evidence.
4. How could human error or variability affect the results in Table 2?
5. Examine your graph of Habitat vs Temperature and Light. What conclusive statements would you make from these two
comparisons?
6. Considering your answers to Question 5, summarize how living organisms affect both biotic and abiotic factors in an
ecosystem.
7. Which ecosystem requires a greater expenditure of human resources to maintain? Explain your answer.
8. If each ecosystem experienced a fundamental environmental change, such as continued climate change, which would be more
likely to survive? Explain your reasoning.
Conclusion
Consider the two hypotheses formed before the field trip, and write a conclusive paragraph for the one with the most interesting or
surprising results. Be sure to address your hypothesis, make a CLAIM, support it with EVIDENCE, and provide scientific
REASONING.
Formal write up due date: Thursday, October 15 or Friday, October 16 (These will be in class work days for students not on JA
field trip and write ups will be due at the end of the period.)
 Title
 2 Experimental Questions and Hypotheses
 Materials list and abbreviated procedures (“. . . as described in field instructions . . . “)
 Data Table #5
 Graphs
 Analysis Questions
 Conclusion