Collecting
Data

Collecting data

After setting up your experiment, follow these instructions to collect data.

1. Grow your plants for 14 days total. On Day 14, you will finish the experiment and collect the remaining growth data.

2. There are multiple different ways to measure plant growth and impacts of competition, including measurements of aboveground biomass (shoots) and belowground biomass (roots). The shape of a plant is sometimes called its “architecture.” Competition can impact multiple aspects of plant growth, and the architecture of a plant can affect competition outcomes, too. Quantifying plant architecture and belowground biomass can be very challenging, so for this experiment we will focus on just a single measurement of a plant shoot characteristic. Specifically, we will use the average total plant leaf size per pot as a measure of the extent of each plant’s growth.

3. It is very likely that not all seeds will have germinated, for reasons that are unrelated to the focus of this experiment. Therefore, you will want to measure average plant size based only on the number of plants of that species that actually germinated and grew.

4. We will use an app to measure the total leaf area for each plant. If plants are small, you can measure more than one individual at the same time and then just divide by the total number of plants. Be sure to only group plants of the same species together when doing this.

5. Clip off your plant shoots at ground level.

6. Obtain a copy of the appropriate scale (more on that in a moment). Arrange your plant shoots on a piece of white paper with the scale positioned next to the plant parts. If the plant leaves stick up at all, you may need to flatten them down with your finger. Place a transparent cover over the leaves to completely flatten them out. If your plant leaves are too big to fit on a single piece of paper, you can cut them into smaller pieces, arrange the pieces to fit, and then just add up the total area to obtain the total leaf area for that plant.

Individual Sharing & Assignment

• use your phone to scan your notes, and upload the resulting pdf to your team's shared drive

• enter your data into your team’s shared Google Sheet

• answer questions on Canvas (Pilot Wrap-up: Individual Assignment)

Team Meeting at the End of the Experiment

Arrange a time to meet face-to-face as team (your choice whether that’s in person, Zoom, Google Meet, conference call, or something else -- but IT CANNOT BE A TEXT CHAIN OR GROUP CHAT! You must actually be able to speak to each other!

At your meeting, you should accomplish the following things. You'll be uploading your notes and answering a few questions in the Pilot Wrap-up: Team Assignment in Canvas

1. Choose one person to take notes.

2. Verify that all students have added their data to the shared data sheet

3. Does anyone have questions about the data?

4. Did anyone encounter unexpected problems or challenges while collecting data?

5. Is there anything from this experience that will be especially valuable in planning your main experiments?

Team Sharing & Assignment

1. Upload your discussion notes to Canvas (if notes were handwritten, upload a photo)

2. Answer the Team Assignment questions in Canvas

Data analysis and presentation

Create two graphs for your pilot experiment. One graph should compare corn plant leaf area for corn grown at low density, high density, and at high density with interspecific competition. The other graph should illustrate the same comparisons for pea plant leaf area.