racemosa and this can be attributed to the fact that plants that are conducive for sunnier and drier areas such as the P. angustifolia have more venation per area to increase water distribution across the leaf so as to help buffer against damage or cavitation of the leaf from drought (Sack, 2006). All three of these characteristics go hand in hand to aid the health of a leaf as stomatal density and size directly can affect transpiration rates which can also be affected by leaf venation which all affect a plant’s health as the leaf is vital for providing nutrients to the plant itself. References Brodribb, T. J., T. S. Feild, and G. J. Jordan (2007) Leaf Maximum Photosynthetic Rate and Venation Are Linked by Hydraulics. Plant Physiology 144.4 : 1890-898 Farquhar, G. D., and T. D. Sharkey. (1982) Stomatal Conductance and Photosynthesis.
Annual Review of Plant Physiology 33.1 : 317-45 Gates, D. M. (1968) Transpiration and Leaf Temperature. Annual Review of Plant Physiology 19.1 : 211-38 Sack, Lawren, and N. Michele Holbrook. (2006) Leaf Hydraulics. Annual Review of Plant Biology 57.1 : 361-81 Figures
Figure 1: Drawings of leaves for experiment three Factor Controlled Average rate of Transpiration Difference from Control (%)
( µL / minute) Cool Wind 16.1634942 94.44444444 Humidity 5.54176944 -33.33333333 Hot Wind 8.31265416 0 Figure 2: Average rates of transpiration and percentage differences from controls for experiment one Plant Species Abaxial Stomatal Density Adaxial Stomatal Density Abaxial Stomatal Size Adaxial Stomatal Size B. vulgaris 22.4 0.4 53.335 3.5 R. integrifolia 30.8 0.8 37.75 30.55 G. biolba 43.8 12.53333333 17 2.334 Polypod sp. 15.53333333 0.066666667 35.58 2 Figure 3: Average stomatal density and sizes for experiment two Plant Species 2nd Order Vein Density (Vein Length/ cm^2) Leaf Size (cm^2) P. racemosa 0.5134861111 148.136 P. angustifolia 1.817 11.1416 Figure 4: Average vein densities and lengths for experiment three
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- Fall '09
- leaf venation, stomatal density, transpiration rate