Wind enhances tree transpiration leading to greater trunk shrinkage

Steps:

• Tree trunks shrink during the day due to water loss from transpiration, reducing cell turgor.
• Environmental factors that boost transpiration rate amplify this shrinkage.
• Transpiration increases with factors that widen the water vapor diffusion gradient from leaves to air.
• Wind speed raises transpiration by removing humid boundary layer around leaves.

Why B is correct:

• Increased wind speed accelerates transpiration by disrupting the moist air layer on leaves, steepening the humidity gradient and driving faster water loss per Fick's law of diffusion.

Why the others are wrong:

• A: Increased light intensity opens stomata for photosynthesis, raising transpiration, but does not directly disrupt air layers like wind.
• C: Increased humidity narrows the vapor pressure gradient, slowing transpiration and reducing shrinkage.
• D: Not enough information.

Final answer: B