Leaf water loss — The process describing evaporation of water from plant leaves (primarily through stomata) is called what?

Introduction / Context:
Water loss from leaves is a central driver of the soil–plant–atmosphere continuum. Naming this process correctly is essential before tackling quantitative topics like transpiration rates, stomatal conductance, and water-use efficiency.

Given Data / Assumptions:

• Most leaf water loss occurs through stomata, with a small fraction via cuticular evaporation.
• Transpiration is influenced by vapor pressure deficit, light, temperature, wind, and stomatal aperture.
• Transpiration indirectly drives mineral uptake and xylem flow.

Concept / Approach:
Transpiration is the evaporation of water from plant aerial parts, especially leaves. It creates tension that pulls water upward through xylem. Cohesion and tension are physical principles underlying movement but are not themselves the evaporative process. Pressure flow pertains to phloem transport and is unrelated to evaporative water loss.

Step-by-Step Solution:

Verification / Alternative check:
Gas-exchange measurements (porometry, infrared gas analysis) quantify transpiration concurrently with photosynthesis, correlating with environmental drivers.

Why Other Options Are Wrong:

• Cohesion/tension: mechanisms within water columns, not the evaporative process.
• Pressure flow: refers to phloem sugar transport.
• Guttation: exudation of liquid water at hydathodes, distinct from vapor loss.

Common Pitfalls:
Equating guttation (night or high humidity) with transpiration; guttation is liquid exudate, not vapor loss driven by VPD.

Final Answer:
Transpiration