Why is stomatal conductance measured at the back of the leaf?

Answer 1

Stomatal conductance is often measured at the abaxial (back) side of the leaf for several reasons:

1. Direct access to stomata: The abaxial surface of the leaf typically has a higher density of stomata compared to the adaxial (front) side. This higher stomatal density allows for easier access to measure stomatal conductance.

2. Reduced interference: The abaxial side is usually less exposed to external interferences such as sunlight, wind, or contaminants, which can potentially affect the accuracy of the measurements. Measurements taken on the adaxial side might be influenced by these external factors, leading to less accurate results.

3. Avoidance of epidermal features: The abaxial surface of the leaf has fewer epidermal features such as trichomes and thick cuticle, which can potentially obstruct the measurement process. These features might interfere with the diffusion of gases, affecting the accuracy of stomatal conductance measurements.

Overall, measuring stomatal conductance at the back of the leaf provides a more accurate and reliable representation of the stomatal activity within the leaf.