ShareLife on Earth - Comparing Biological Diversity
A forest has a greater amount of biodiversity than
a desert. The term biodiversity refers to the variety of
living things that can be found in a particular area. One of the easiest
ways to measure the biodiversity in an area is to count how many different
species live there. Another helpful measurement is to also count the
number of individual members of each species in the area.
Your challenge in this activity will be to count and chart the biodiversity in a small area near your school or home.
Materials:
- Tennis ball
- Meter stick
- 8 meters of string
- Four popsicle sticks (or similar)
- Paper
- Pen or pencil
- Clipboard (optional)
Procedure:
- Step out into your yard at school or at home. Turn your back on the largest part of the yard and toss the tennis ball back over your shoulder into the yard.
Go
to where the tennis ball landed and use the meter stick, string and
popsicle sticks to stake out a square area that is two meters on each
side. Make the square so that the tennis ball is in the middle. You
won't need the tennis ball after this. You use it to randomly select
your area. - The square outlined by your string is your study area.
- Describe the area by writing in your laboratory journal. Where is it located? (Is it in the middle of a lawn? Is it in a wilder part of the yard?) Does this area get watered regularly? Be specific as you describe all you can about the abiotic and biotic factors that influence this small area.
- Now take your paper and pencil. Walk slowly around the outside of your study area begin to count how many different species of plants there are inside the square. It doesn't matter if you know the names of the species. It may be helpful to collect a leaf from each species so you can tell them apart in the next step.
- Make a data table similar to the one here. Change the number of columns to be the same as the number of species you found.
- Walk very slowly around your study area again and count the number organisms of each species. Estimate where you must but be as accurate as you can. Write the total for each species in your data table.
| Species 1 | Species 2 | Species 3 | Species 4 | Species 5 |
Analysis:
- Compare your data to those of other friends. Compare the descriptions they wrote in step 4 of the procedure with the description you wrote.
- How is the number of organisms similar or different as you compare your survey area and that of your friends?
- Were all plots equal in the number of each type of organism that is present in the plot?
- How would you describe the similarities and differences between your area and at least one area studied by a friend?
- What abiotic and biotic factors were different in the two study plots?
- Why do you think the study areas were similar or different?
