Certified Landscape Irrigation Auditor

What effect does lower humidity have on water loss from plants?

1. Reduces overall water loss

2. Increases water retention

3. Leads to higher water loss

4. Has no effect on water loss

The correct answer is: Leads to higher water loss

Lower humidity in the environment increases the rate of evaporation of water from plant surfaces, including leaves. When the humidity is low, the air has a higher capacity to absorb moisture, resulting in a greater gradient between the moisture inside the plant and the drier air outside. This condition prompts plants to lose water more rapidly as they transpire to maintain their internal moisture balance. Consequently, as plants release water vapor during the process of transpiration, the lower humidity levels drive more water loss. This phenomenon is critical for managing irrigation strategies, as plants will require more frequent watering under such conditions to compensate for the increased water loss. Understanding this relationship is vital for effective landscape irrigation auditing and management.