Ulmus Solar Radiation 12 Fall 2016


The researchers hypothesized that solar radiation was correlated to photosynthetic efficiency (𝚽II) and LEF (linear electron flux) and not related to chlorophyll content (PQ SPAD). The students found this an area of interest because on Michigan State University's campus there were many trees of similar genius and species spaced about. The students wanted to see if the tree's location had any effect on chlorophyll production versus solar radiation. No one has ever done a study similar to this before but it would be great background science for a future study. When plants absorb light, they are not always efficient in converting light energy to chemical energy. The amount of light energy absorbed converted to chemical energy is referred to as photosynthetic efficiency (𝚽II). The path that the electron follows after being excited is called the linear electron flow (LEF). Green plants were found to contain spectral dynamics of incident solar radiation and increased in PAR absorption (Kume et. al., 2016).

It was hypothesized that solar radiation was correlated to photosynthetic efficiency and LEF but not correlated to chlorophyll content (PQ SPAD). The expected outcomes will help explain the relationships between solar radiation and the three variables and how they relate to each other. Since this has never been done before, this research is good for future agricultural studies. Photosynthesis is the process when sunlight hits a leaf and it uses the energy to produce life sustaining compounds. Chlorophyll is a pigment that absorbs photons of light and immediately after loses an electron; that electron travels down the electron transport chain to eventually reduce NADP to NADPH.However, plants are not always in direct sunlight so the goal was to assess the difference in chlorophyll content (PQ SPAD) between plants the spend most of their time in direct sunlight and plants that spend most of their time in the shade.

Trees located on Michigan State University’s campus between the Natural Science Building and Giltner Hall on Collingwood Road. Each tree was sectioned into cardinal direction quadrants. Starting on the northeast quadrant, a researcher stood on the second step of a step stool to randomly measure five dry, exterior, green leaves with MultispeQ device #208 (Kuhlgert et al., 2016) using Tablet #2. Measurements were accepted (ΦII, LEF and PQ SPAD) based on photosynthesis trace. The researchers moved clockwise around each tree to collect 20 traces per day per tree before moving to the next tree. Readings were temporarily stored on Tablet #2, then immediately uploaded data to PhotosynQ website. Collected 120 traces per day, on thirteen different days over four weeks. Following the data collection, the data was used for Pearson’s Correlation Coefficient (PCCr) analysis of mean solar radiation relationship to mean ΦII or LEF or PQ SPAD for quadrants, individual trees and combined similar trees at vassarstats.net. Solar radiation data was downloaded from Michigan Automated Weather Network.

Sampling Protocol-- Select tree and its specific code

  1. From an aerial point of view, the tree is sectioned into fourths.

  2. From these fourths, stand in front of the northeast quadrant on the second step of a step stool.

  3. To blindly select one dry, exterior, green leaf within reach anywhere in the quadrant.

  4. Repeat step 3, four more times. Be sure to select only 20 green leaves total per tree (5 from each of the 4 quadrants).

  5. Be sure that there is a total of 120 measurements by the end of the sampling period.

Using MultispeQ device #208 and Tablet #2

  1. Answer the questions on the MultispeQ accordingly

  2. Make certain that the phi2 and SPAD III traces are correct prior to accepting the data.

  3. Measure a total of 5 leaves per quadrant.

  4. Move in a clockwise direction to obtain all measurements of the tree. (northeast to southeast to southwest to northwest)

  5. Move on to the next tree and repeat steps 1-4

Notable Information:

The students compared the trees with tree codes of 20080057'01, 20080057'02, 20080057'03, 20080496'04, 20080496'03, and 20080496'01.

When comparing the data, the data with ID#388838-388847 are under tree code 20080057'02. The data should be under tree code 20080057'01.

20080057*01.jpg 20080057*01

20080057*02.jpg 20080057*02

20080057*03.jpg 20080057*03

20080496*04.jpg 20080496*04![Screen Shot 2016-12-07 at 2.23.04 PM.png]


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


  1. What Ulmus tree code is being tested? (Multiple Choice)
  2. Which quadrant are the samples being taken from? (Multiple Choice)
  3. Which sample number is being taken in this quadrant? (Multiple Choice)




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