Alien Plant Invasion: A Field Study project at Saguaro National Park
V. Graphing Techniques and Final Report
The students should choose the most appropriate type of graph for displaying this kind of data. A pie graph is not appropriate because the total coverage can be more than 100% (due to overhanging leaves). A line graph is difficult to read and understand. A bar graph showing the native coverage next to the non-native coverage would be effective in comparing the coverage values for each.
Students should sketch their graphs prior to using the computer. They should understand the scale they would like to use and which data will be displayed on the X axis versus the Y axis. The students can use the computer to make each kind of graph and then decide which graph is the most effective in showing the results. This one graph would then be printed out.
A conclusion for this study is simple. Because the study site exists on a national park, there is a zero tolerance for alien species. If there are any alien species, steps should be taken to eliminate them. Simply stating the percent of coverage by each type of plant (native vs. alien) and then describing the data will suffice.
The supporting student materials may be found in the following handouts:
The University of Arizona
Department of Biochemistry and Molecular Biophysics
General Biology Program for Secondary Teachers