Complete the field notes forms with a count of the number of stems per square meter for each plant species found. Rotate the quadrat by 45 degrees and repeat using a different group of students. Combine the field notes to calculate the percentage of stems of loosestrife in the plot. Also use the data to calculate the diversity index for each plot. On a piece of graph paper, plot the diversity index for each quadrat as a function of the density of purple loosestrife in the one meter squares.
Extensions Using standard references, find and use different diversity indices to compare the plots.
Remove all loosestrife plants from the same ten meter square plot as soon as growing plants can be identified in the spring and keep the loosestrife plants from growing by periodic weeding during the summer. Calculate the diversity index for the same plot the following September. Having groups do a poster or presentation on the investigation and its results. All rights reserved.