Download Leaf Litter Field Journal ( file)

Biological Diversity Field Study
Task
From where you are standing,
how many different plants can
you see?
Stand quietly for at least 2
minutes. Record the number of
birds that you see or hear.
Name the different kinds of
sounds that you hear?
I am in a biologically diverse
place. (Yes or No)
I found a rock with living things
on it or under it. (Yes or No)
Find an animal with 6 legs.
What is it? (Yes or No)
I found an insect living in the
soil. (Yes or No)
I found an animal with no legs.
(Yes or No)
Find insects living in leaf litter.
Name them.
How many different types of
plants are in a 5 foot square?
Name a change made by
humans that decreased
biodiversity.
Name a change made by
humans that increased
biodiversity.
Answer
Collect Leaf Litter
Materials:
 Trowel
 Gloves
 Large collection bin and lid
 Collection tray
 Magnifying glass (or loupe)
 Tweezer
 Measuring tape
 String
 Golf tees
 Pencil
 Field journal
 Identification key
Procedure:
1. Find a place in the school yard that has been relatively undisturbed
by human activity. There should be fallen leaves, twigs, and pieces
of bark.
2. Measure out a patch of leaf litter, one-yard square. Use the string
and tees to build a rough sampling frame. Have you seen any
animals in your sampling area so far? How many animals do you
think you will find?
3. Put on your gloves and use the trowel to collect all the leaf litter and
soil to about ½ inch depth within your sampling frame.
4. Put all the leaf litter in the large collection bin. Using your fingers
(keep gloves on), spread out the leaf litter so an even layer is
created. Keep your eye out for little critters!
5. Return to the classroom.
6. With your magnifying glass, examine the leaf litter for any worms,
spiders or insects. Use your gloved fingers to gently sift through the
litter.
7. Using tweezers, gently place any animals found in the litter into the
collection bin’s lid.
8. Examine the small animals. How many legs are there, if any? Do
they have an exoskeleton or a hard shell? Do their legs look jointed?
What color are they? What shape are they? Are there different
sized critters? Scientists use questions like these to categorize
animals into different groups.
9. Record your data in the following lab record sheet.
10. Return all specimens and leaf litter to where you originally found
them. Bring all sampling equipment back to the classroom.
11. Compare the results of your field study with others in your
classroom.
Species Evenness
Sorting and Counting Litter Critters
Species Richness: Total number of species
Date: _______________________________
Species richness for my leaf litter plot: ________________
Describe the area where your litter critters were found.
Species Evenness: How evenly distributed the species are in a designated
community.
Use the table to record your collected data. You do not have to identify
the organism. You can name the organisms Beetle 1, Beetle 2, Beetle 3, Or
Organism A, or Organism B, Organism C, etc.
Species Name or Description
Quantity Found
Species Evenness = Number of individuals of one species found
Total number of individuals found in a habitat
Here is an example of the calculation for species evenness:
Species
Total # Found
Beetle A
Beetle B
Worm A
Total
25
50
10
85
Total # of
Individuals
85
85
85
Species Evenness
Ratio
25/85 = 0.294
50/85 = 0.588
10/85 = 0.118
1
Determine the species evenness of each individual species and record in
the table below.
Species
Total Individuals
Draw your litter critters.
Total
Total # Found
Total # of
Individuals
Species Evenness
Ratio
Simpson’s Diversity Index
Numerator
The Simpson's Diversity Index is an index that represents a quantitative
measurement of a habitat’s biodiversity. It takes into account the number of
species present, as well as the species evenness.
n(n -1) =
Denominator N(N-1) =
Procedure:
Where: n = the total number of organisms of each individual species
N = the total number of organisms of all species
The value of D ranges from 0 to 1. With this index, 0 represents
infinite diversity and, 1, no diversity. That is, the bigger the value the
lower the diversity.
Jelly Bean Community
Species
Total
n (#
individuals)
N=
n–1
1. Divide your species (jelly beans) by color into groups.
2. Name your species (green jelly bean, red jelly bean, etc.) and
list them in the first column under Species.
3. Count how many of each species you have and note that
number in the second “n” column.
4. Subtract 1 from each number in the “n” column and place it in
the “n-1” column.
a. i.e., 5 green jelly beans, 5-1=4
b. Multiply column “n” by column “n-1” i.e., 5x4 =20.
Place that number in the last column “n(n-1).”
n(n – 1)
5. After you’ve finished this calculation from each species, add
up the numbers in the fourth column. n(n -1) = ??. This is
your numerator (top number).
6. Count all of the jelly beans on your plate. That is your N
number. (You can also add the number is the “n” column.
7. To get the denominator, multiply your “N” number by “N-1.
8. Divide. Your number should be less than 1.
n(n -1) =
Comparing Leaf Litter Samples
1. What kinds of organisms are most common in leaf litter?
2.
Why are leaf litter organisms important? 10. What would happen if
the organisms that eat and live in leaf litter disappeared?
3.
4. Which leaf litter collection in the classroom has the great species
richness? Why?
5. Which litter organism in the classroom has the greatest species
evenness ratio?
6. Which litter organism had the lowest species evenness ratio?
7. What was the Simpson’s Diversity Index for your sample? Does this
indicate a low or high level of diversity? If the diversity was low, why
might that be so?
8. Describe the differences in the Simpson’s Diversity Index among the
different student groups in your class. Was there a great deal of
difference in the calculated index? Does this surprise you?
9. If there were differences in the calculated index among the student
groups, give some reasons for this variation.