Plant Transpiration Lab Report

Lab 4: Plant Transpiration Project By Shelby Hyde Lab 030 Date Due: March 12, 2013 The Effect of Wind on the Rate of Transpiration Introduction: Transpiration is the process through which water is evaporated from plants. This serves many purposes, including thermoregulation and the diffusion of CO2, but most importantly creates a water potential difference which causes the mass flow of water and nutrients from the roots to the leaves of the plant. Transpiration is accomplished through structures on the surface of the leaf called stomata, which are guarded by a pair of guard cells.Guard cells control the opening and closing of the stomata as well as the size of the opening; they open in order to obtain O2 and CO2 in the process they allow the escape of H2O. This experiment was conducted to learn more about this process, and how certain common environmental factors affect it. Plant transpiration increases with the presence of wind due to increased evaporation from leaves. Results: The transpiration rate of the sunflower in the presence of wind was consistently greater than that without wind, also causing the mean to be higher, shown in Table 1.Also included in Table 1, the variability was less in the sunflower with wind along with standard deviation. Table 1: Rate of Transpiration in sunflower plant with and without wind. Discussion: Although the rate of transpiration was consistently, noticeably greater while wind was present than it was in the absence of wind, there were some limitations to this study. One of the limitations of the experiment is that was performed in a college lab setting with various activities simultaneously going on, which could’ve affected the speed of the wind between all of the runs.The main shortcoming is that, because only one plant of one species was used, this cannot be used to generalize that this is true for all plants. In general, the results support the hypothesis that the rate of transpiration is higher in plants while win d is present. Transpiration increases in the presence of wind for two main reasons. When the stomata open, the wind would increase evaporation and the amount of H2O that escapes from the open pores.Also, when water is transpired it remains around the plant, causing area within the vicinity to become humid. Wind pushes that saturated air and replaces it with drier air, which is easier for water to evaporate into. Further studies could include not only other variables affecting transpiration, such as relative humidity of the atmosphere, temperature, pH of water and amount of available water, but also how much each of those individual variables contribute to the rate of transpiration in relation to each other.Literature Cited: George Burba,  Michael Pidwirny  (Lead Author);Debbie Swarthout  (Contributing Author);Sidney Draggan Ph. D. ,  Daniel Robert Taub  (Topic Editor) â€Å"Transpiration†. In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D. C. : Envi ronmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth August 3, 2010; Last revised Date December 16, 2010; Retrieved March 13, 2013