1. Using Quantification and Communication Skills
A Transect Study
Using Quantification and
Communication Skills

2. A Transect Study
This activity allows students to gather data and manipulate it through the use of a data table and graphs.
The activity also uses numbers to quantify.
Be sure to review the Science Processes before starting the activity.
Complete each slide before moving to the next.
Answer all questions posed during the activity.

3. Materials Access to an outdoor area. A calculator.
A data table constructed like the one on the next slide.

4. See instructions in the next slide...

5. Step 1: Construct the data table.
Divide a full sheet of paper into 7 columns of “Features” and 25 rows of “Inventory Sites”.
Leave room at the bottom for additional two rows. One for “Column Totals” and one for “%”.

6. Step 2 Select the area of study.
Write a narrative description of the area.

7. Step 3
Determine a starting point then pick a landmark. (In this picture my landmark is the yellow tree in the distance.)
From the starting point, take 25 observations along the line toward the landmark. Each of these will be one large step from the previous one.

8. Step 4: Using the data table.
Record your observations of the features at each inventory site on the data table.
Each inventory site represents an area about as large as your hand, one pace apart, along the straight line between the starting point and the landmark.

9. Step 5: Identifying features
Natural litter consists of dead plant material.
Two features can be seen in this picture, grass and natural litter.

10. Step 5, continued
Forbs are green plants other than grass. The term is a generic one in the same way that weed is a generic term.
A forb, grass and natural litter can be seen in this picture.

11. Step 6
At each site you might find one or more of the features listed on the Table.
For example, at Site 1, you might find soil, rock, and natural litter. In this case you would note that on your Table by placing a mark (-) in each of the appropriate cells.
Next, and before moving to the next site, you must make a decision about which of the features is the dominant one. (You must operationally define dominant feature.)
Distinguish the dominant feature by noting it as (+). There can be several features at each site but only one can be dominant.

12. Dominant features Here one can see grass, natural litter and a forb.
Which one seems the most predominant to you?
What operational definition are you applying?

13. Step 7
Once you have completed the 25 observations add the number of marks (-/+) in each column. Record that number in the “sum” row.
Determine what percentage each feature is of the total transect. (For those of you arithmetically challenged divide each column total by the total of all columns.)
This information along with the narrative you wrote in Step 2 provides you with both a qualitative and quantitative description. How do the two differ?

14. Step 8: Tree shrub forb grass litter soil rock
Plot the dominant features on a line graph like the one below. Connect the points with a
line. With the first point being “1” count the number of times the line changed direction as
observations moved from one site to the next. Since there are 25 sites there can be a
maximum of 25 changes and as few as 1. On this graph there are 14 direction changes.
Tree
shrub
forb
grass
litter
soil
rock
sites
1……………………………………………………………………………………………………………25

15. Step 8, continued:
Calculate the Diversity Index (DI) by dividing the number of times the dominant feature changed from one site to the next by the number of times it could have changed (25).
For example, on the previous slide the dominant feature changed 14 times as you moved from one site to the next. Therefore DI would be 14/25, or .56.

16. Step 9 Post answers to the following questions:
Ecosystem diversity is sometimes used as an indication of ecosystem health. Why is diversity such an indicator?
Identify how communication skills were used in this activity.
How did we use quantification?

17. The Transect Study is finished!