Plant Transpiration Lab Report

Transpiration, Stoma, Plant nutrition

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...
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