Final answer:
When evapotranspiration decreases due to reduced rainfall, plants conserve water by closing their stomata, potentially leading to stunted growth and leaf shedding. Dry soil also has a lower water potential, slowing down water movement to the plant and causing stress.
Step-by-step explanation:
If evapotranspiration decreases past a certain point in which there is less rainfall, a series of changes can occur in the plant-soil water relationship. Under drought conditions, the plant's stomata, which are tiny openings on the leaves, close to conserve water. This conservational response reduces water loss but also limits the intake of carbon dioxide needed for photosynthesis. Consequently, the plant's growth can be stunted, and leaves may eventually be shed to further reduce water loss. The soil, being drier, has a lower water potential than moist soil, meaning that water will move from the soil to the plant more slowly. This decrease in water availability can make it difficult for plants to maintain their normal metabolic processes, potentially leading to plant stress or even death if the drought persists.