The Effect of Stomata Density on the Midrib and Margin of Woody Dicot Leaves
March 25, 2014
Lab Partner: Christina Pham
Plants are relied heavily on their ability to exchange water and gases to keep life on Earth alive and well. Tiny, microscopic pores that are found on the surface of stems and leaves in plants are vital in order for this exchange to occur. These pores, or openings, are called stomata (Freeman, 2011). Stomata are mainly open when photosynthesis is occurring, which takes place during the day, and are closed at night. The stomata also tend to open and close in response to various stimuli and physiological states. Stomata density is the number of stomata per leaf area. Photosynthesis is certainly higher at the margin of the leaf rather than the center of the leaf; this is due to the fact that the edge of the leaf can be particularly active, mainly in cooler climate (USA, 2014). Therefore, toothed leaves are more prone to be able to exchange gases more relatively. Furthermore, leaf margin analysis can be used to determine what the climate is during a time period. Back in 150,000-year period, oxygen exchanging gasses within the fossil was documented, thus in this experiment LMA will be tested to see if more stomata are in the margin of the leaves.
In this experiment we will determine the amount of photosynthetic gases that are being exchanged to determine the uptake of carbon dioxide while water and oxygen is being released into the external atmosphere. This data will be used to determine the climate of the environment. In order to determine this, counting of smooth leaves, tooth leaves, and the stomata within the midrib and the edges of the leaves will be accounted for. The null hypothesis will conclude that there is no effect on the increase of stomata density within the center. The alternative hypothesis will conclude that there is an effect on the increase of stomata density within the center.
In this experiment woody dicot leaves were used to determine the stomata density count within the leave margins and edges. In the first process the experimenter investigated the amount of fossil leaves to estimate the temperature from before and during the PETM. In the fossil leaves, the numbers of smooth leaves versus the toothed leaves were counted. After the numbers amount of smooth leaves and tooth leaves are counted, we used the Average Annual Temperature (AAT) to find the percent smooth and temperature of the samples from before and during. Next, in the investigation the actual Average Annual Temperature for mobile by predicting the percent smooth leaves that the class found in the camellia bush located near the SE corner of Life Science Building was accounted for (USA, 2014). Following that we used was the actual percent of smooth leaves to see accurately predict the AAT...