Inside vs Outside Photo-Efficiency in Ulmus Mortons


Photosynthetic Efficiency of *Ulmus Morton *leaves on inside and outside of the canopy.

Plants have different photosynthetic abilities. Some plants need the sun and some thrive in the shade. Boardman (1977) claimed that plants that occupy shaded habitats are incapable of high photosynthetic rates; yet, they do perform efficiently at low light intensities. In contrast to Boardman, Loach (1970) found that tree seedlings with different shade tolerances had very similar photosynthesis rates and rates of respiration when grown in full daylight or shaded conditions. Leaves on the outside of the trees get higher amounts sunlight; therefore, based on previous research, the values should be different. This study was done to see if there was a difference in Phi II, LEF, SPAD content on the inside versus the outside for the canopies of Ulmus Mortons. Our study allows us to see how the amount of light affected our stated conditions. According to Reich et al. (1998), it was determined that, in low light, all species allocated proportionally more biomass to stems and less to roots, but the same to foliage, compared with the high-light environment. It was measured how Phi II, LEF, NPQ, and SPAD content were affected by leaf placement on the inside versus the outside canopy of Ulmus Mortons.

The research hypothesis is that the values of Phi II, LEF, and SPAD will be different on the outside leaves vs. the inside leaves. The outcome we expected was for the values to be significantly different. With the results we can see whether the leaves on the inside have the same photosynthetic efficiency as the outside leaves. This contributed to our understanding of how crops are spread out in fields so there are equal amounts of light hitting the crops in the same way. The research of this subject will be advancing with new technology and with variation of species. By using more species the research would advance because as knowledge is expanded there will be more applications available using the data that is collected.

For our sampled comparison, we used three Ulmus Morton trees on the West of North Kedzie in MSU campus. The devices used were multispeq #127 and phone #1. This multispeq measured the variables of Phi II, LEF, and SPAD content. Each tree was separated into eight sections, consisting of 4 quadrants (northwest, northeast, southeast, southwest) split into 2 sections per quadrant (inside and outside). The inside portion of our tree is 4 feet away from the tree trunk and the outside portion is everything past this 4 feet limit. Specifically, 5 leaves were sampled from each of the 8 sections on the trees. Each day of measurement, there were three biological replicates and 40 technical replicates, therefore having a sample size of 120 leaves. They were sampled by randomly choosing a leaf on the outer section (section closest to the edge of the tree for both the outside and inside portion of the tree) and then leaves were randomly picked in a clockwise motion. When the randomly selected leaf was chosen, the PhotosynQ device to collect our data by measuring from the center of the leaf. A statistic analysis that was used was the t-test, this allowed us to determine if these data from inside and outside leaves were significantly different from each other.


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. Ulmus Mortons tree code was? (Multiple Choice)
  2. Which quadrant of tree sampled? (Multiple Choice)
  3. Leaf location on bottom of canopy? (Multiple Choice)
  4. Randomly selected leaf counted in the quadrant/section? (Multiple Choice)



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