Directive As part of our BS172 lab class our research group was asked to use the MultispeQ device and its capabilities to form a scientific question and subsequent data and analysis. With our research we are going to analyze how the photosynthetic efficiency relates to the physical surface area randomly sampled leaves on a group of Accolade Elm trees (Ulmus japonica x wilsoniana 'Morton') around the area of our research building. This data and analysis is available to the whole public and is even open to contribute your own data.
Thoughts and Research
Our research focused on the relationship between surface area and photosynthetic efficiency on the population of four Accolade Elm trees located on Michigan State University’s campus. Photosynthetic efficiency is the amount of energy absorbed and utilized by the plant. Due to certain factors, not all energy harvested is actually used. In a study performed by Parkhurst and Loucks (1972), it was evident that leaf size was directly influenced by its environment which dictated its phenotype and therefore ultimately its internal structure. The smaller leaves were found to have less chloroplasts which decreased its ability to perform photosynthesis. Our research questioned if surface area was one of these factors. The MultispeQ is a device that uses innovative technology to study plants in their natural environment, as opposed to a controlled lab setting. We utilized the MutlispeQ device to measure and trace the intensity of Phi2 and SPAD levels within the Elm Leaves. We were compelled to study this specific topic to understand possible implications our results might have on reducing carbon emissions and using plants as a tool to do so.
We hypothesized that there would be a positive linear relationship between surface area and photosynthetic efficiency. In a study conducted by Khan and Tsunoda (1970), there was a positive correlation between photosynthetic rates and leaf surface area. This data supports the logical assumption that bigger leaves caused “increased utilization of solar radiation” and were therefore noted as more photosynthetically capable. If our results support our hypothesis, the information may be helpful in the realm of global warming and finding innovative ways to absorb excess carbon from the atmosphere. Carbon sequestration is a relatively new field, and researchers are currently exploring high technology ways to do so. Various aspects of photosynthesis components have been affected based on the size of the leaf before. CO2 and stomatal conductance were two of the most mentionable (Chartzoulakis, Patakas, and Bosabilidis, 1999), regarding what limited or allowed the leaf to utilize and absorb light energy because of its size. Our research may prove that by working with nature, we are able to store excess carbon long term while saving money.
Methods Our population consisted of four Accolade Elm trees located on Michigan State University campus. We divided each tree into quadrants: NE, SE, SW, NW. Starting in the NE quadrant and moving clockwise, we randomly selected 5 samples (leaves) on the outer portion of the branches. This resulted in 20 readings per tree, or 80 readings each day the measurements were taken. A caliper was used to gather information on the surface area of each leaf selected, measuring the major and minor axis in centimeters. These numbers were applied to the equation used to determine the area of an ellipse (pimajorminor). We decided to use that formula because it most closely resembles the shape of the elm leaf. After taking and recording the leaf measurements, we used the MultispeQ device. This information was automatically synced via bluetooth to an Android device, and later synced to our Photosynq website. Our data was translated into charts that helped us analyze our data by focusing specifically on surface area, Phi2 levels and PQ SPAD levels. A t-test will be performed after all the data is collected to further analyze the results and statistically determine significance or not.
Random Sampling We divided each tree into quadrants: NE, SE, SW, NW. Starting in the NE quadrant and moving clockwise, we randomly selected 5 samples (leaves) on the outer portion of the branches. This resulted in 20 readings per tree, or 80 readings each day the measurements were taken. The order of trees doesn't matter but each time we started with the northern most tree.
- Leaf Photosynthesis - MultispeQ Beta ONLY
Measures photosynthesis-related parameters in <15 seconds, including: Phi2, PhiNPQ, PhiNO, NPQt, qL, LEF, and SPAD. In addition, measures PAR (photosynthetically active radiation), ambient temperature and relative humidity.
Works with the MultispeQ Beta device only
- Tree Code (Multiple Choice)
- Sample # per tree (Multiple Choice)
- Quadrant leaf is on tree (Multiple Choice)
- Leaf major axis value (cm) (Short Answer)
- Leaf minor axis value (cm) (Short Answer)