Embedded Files
Background Information
Background Information
Our scientific question aimed to discover if the treatment of the plots in the prairie would affect the average heights of Big Bluestem in the area. We thought that more forbs in the area would decrease the average heights of grasses, through the theory of interspecific competition. This process is the competition between different species over the resources in their ecosystem. Although we did not measure this in our experiment, we also considered the way that grasses influence the prairie and the plants around it. They allow a safe spot for insects and larger animals alike. These grasses and wildflowers can be used by pollinators, which are extremely beneficial for this prairie environment.
The Free State High School prairie contains 18 separate plots, each containing different plant compositions. There are 6 plots without forbs, 6 plots with a normal amount of forbs, and 6 plots with 2x the normal amount of forbs. We selected 6 plots to take data from, with 2 plots in each of 3 different treatments.
Our Free State prairie, as well as most prairies in general, contain tall grasses throughout a large expanse of open land, as well as very minimal tree coverage. The Free State prairie was finished in 2014, and has been gradually growing back to its former glory. This prairie restoration was made originally as a scientific experiment by Julie Schwarting, who wanted for her students to “experience a more complex, native ecosystem.” (Free State High School. (n.d.)
Data Collection Methods
Data Collection Methods
We took our data in the Free State High School prairie, looking at information from various plots. We used two yardsticks, and measured the heights of patches of Big Bluestem that were more than 2 feet apart from one another. We used plots that were all spaced close together, in order to keep the variation of sunlight and water to a minimum. We used the following areas of prairie to gather our data: Plot 4B, 5B, 6A, 6B, 6D, 10D, and 12C. We made sure to only use the quadrants of these plots that were the closest together in order to prevent any variation in our data due to differences in soil, sunlight, and precipitation.
Once 10 samples from each plot were collected, we averaged all of them out to find the average height of each plot, and compared them to one another based on the distribution of forbs the plot contained.
The image to the right is a map of our prairie which would be helpful if someone was to replicate our experiment.
Data Table/Graph
Data Table/Graph
Conclusion
Conclusion
Our results did not provide any concrete data for our question of: “How will the amount of forbs in a certain plot affect the height the big bluestem grows to?” After measuring the height of the grasses from each plot and analyzing our data, we didn’t notice any difference of the grasses’ height being affected by forbs.
In our data, we took 10 samples from one quadrant from 6 plots. Plot 6 was grasses only, 4 and 12 contained 1x forbs, and plots 5 and 10 contained double forbs. In plot 4B, we found an average grass height of 178.3cm per blade. In plot 5B, we found an average grass height of 189.6cm per blade. In plot 6A, we found an average grass height of 223.8cm per blade. In plot 6B, we found an average grass height of 175.29cm per blade. In plot 6D, we found an average grass height of 174.33cm per blade. In plot 10D, we found an average grass height of 193cm per blade. In plot 12C, we found an average grass height of 173.4cm per blade.
The height of forbs varied throughout the different plots’ treatments, and did not follow any specific trends throughout the data. We believe this occurred due to a lack of data samples, in addition to not removing as many variables from the experiment as we thought we did. Another reason for this would be starting our data measurements at a point in time where the grasses were all in different stages in their growth, and therefore some might have had a headstart over the other species.
The image to the right is a picture of big bluestem in the Freestate prairie the which is type of grass that we measured in our final experiment.
Next Steps
Next Steps
After thoroughly analyzing our data, our question was not confidently answered. We would like to collect our data in a more controlled environment, where other factors, such as soil quality, do not influence the heights of the grasses in the prairie. We would also like to gather more data, which would require more time in the field. One major source of confusion and possible inaccuracy in our data collection was in plot 6A, where the heights of the grasses far exceeded the rest of the heights in the prairie. This large outlier makes us doubt our methods of control in the external influencing variables in the heights of the grasses. The data we collected consisted of 10 samples from each plot, and we would like 10 more from each during a single day to be more confident in our data.
The image to the right or bottom is a picture of the prairie we experimented in.
Bibliography
Bibliography
Research Website
History of the Project. Free State Prairie. Retrieved 10 / 14, 2021, from https://freestateprairie.wixsite.com/mysite/origin)
Cover Image
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