PLOT SAMPLING WOODY VEGETATION
Read "Quadrats or Sample Plots" on pages 724 and 725 in your textbook
before your lab period.
For this lab you will calculate the following values from your raw data.
Abundance (N): the number of individuals in a given area. Calculate
for each species in each plot.
Density (D): the number of individuals expressed per unit area
or unit volume. Calculate for each species in each plot.
Example: A species has an abundance of 100 individuals in a particular
area. If the total area is 2.5 square meters, then the density of the
species is 40 per square meter.
Frequency (f): the proportion of the total number of samples taken
that contains the species in question.
Example, A species is found in 7 out of 10 samples taken, It would
have a frequency of 7/10 or 0.7.
Mueller-Dombois and Ellenberg Index of Similarity (IS):
IS= 2(C)
A + B
IS= Index of similarity
A= total number of taxa in sample one
B= total number of taxa in sample two
C= number of taxa in both samples
Example:
Plot 1
Plot 2
White oak
White oak
Red oak
Sweet gum
Water oak
Water oak
Loblolly pine
Loblolly pine
Wild plum
IS = 2 (3)
4 + 5
IS = 6
9
IS = .66
The nearer the IS is to one, the more the samples are alike.
Some common trees of the TSU Arboretum:
Trees of
Alabama and the Southeast
Silvics of North America
