Prairie Lab REPORT

Coenocline Variation in a Prairie Pothole Found in an Iowan Prairie Cain Geesaman, Miguel Pradas, Cheng Tsai, Claire Allen Abstract: This lab aimed to identify plant species within a coenocline at Doolittle prairie in Story Country, IA. A coenocline represents a community gradient that displays changes in plant species along the given transect. The hypothesis tested was that species are distributed in groups along the coenocline. There are actual, distinct plant communities. Students used measuring tapes, 1m x 1 m quadrat, plant identification guides, and a data sheet to complete this lab. Quadrats were placed on the ground to estimate plant coverage percentage within the quadrat. This process was repeated 20 times, and throughout those trials, Cordgrass, Bull Rush, and Reed Canary Grass showed frequent overlap. Cordgrass was the most prominent, followed by Bull Rush and then Reed Canary grass. Species overlap was the most pronounced near the Prairie pothole, but then declined the further away you got. Implications of the findings during this lab were impacted by the mowing that had taken place prior to the arrival of these students. This mowing made it nearly impossible for students to identify species in the middle ring which has major implications on the collected data. Introduction: In this Observation students examined a coenocline found along a wet to dry moisture gradient at a prairie pothole, depressional wetlands, in the Doolittle Prairie in Story Country, IA. A coenocline is a series of vegetation zones along an environmental gradient. The studied hypothesis, Species are distributed in groups along the coenocline. There are actual, distinct plant communities. This is known as Clement’s organismic or holistic hypothesis was compared to a hypothesis claiming the opposite. This hypothesis, Species are individually or individualistically distributed. There are no distinct plant communities; plant communities are human constructs. This is known as Gleason’s individualistic hypothesis. The Scientific Objective of this lab was to determine the abundance of dominant plant species along the coenocline of a Prairie pothole in Story County, IA.

Methods: During this lab students were given Measuring tapes (50 m), 1 m x 1 m quadrats, Plant identification guides, data sheets, and videos to watch prior to attending lab. The students showed up to the lab and walked to an Iowa State University parking lot and entered a van. This van then took them to the Doolittle Prairie in Story County, IA. When reaching the prairie, the students exited the van and walked to the closest prairie pothole. They then used the measuring tape to measure 50 m out from the center of the pothole. Then the students placed down their 1 m x 1 m quadrat randomly on the ground and were told to estimate the plant abundance of species within the quadrat. They then recorded the percentage of each plant coverage on their data sheet for that specific quadrat. The quadrat was then flipped twice in the direction of the tape prior to recording the next pant abundance. This one done to prevent the students from accidentally identifying the same plant twice. This was done 20 times until reaching the end of the 50 m tape. The student then headed back to the lab and analyzed the collected data. Results: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 0 10 20 30 40 50 60 70 Plant Species Distribution Cordgrass Dogwood Poison Ivy Water Plantain Common goldenrod Reed canary grass Saw tooth sunflower Bulrush White aster Common Sunflower Swamp milkweed Barnyard grass Environmental Gradient Abundance of Plant(s) (Graph 1) The graph above (Graph 1) depicts the plant species along the Doolittle coenocline, these plants were found from the center of the prairie pothole to about 50 m out from the pothole. The above data displays that distinct plant colonies do in fact exist, proving that Clement’s Hypothesis was correct.

Future studies: For a future study, students could go to the same Doolittle Prairie but each group of students could examine a different prairie pothole, or other locations found within the prairie to identify if potholes share the same species type from pothole to pothole or if the potholes are dominated by species they encounter. Gathering the equivalent total of quadrat’s students could then create graphs and the graphs could be compared to see how these prairie potholes are dominated by various species.