Final answer:
Transpiration in plants is affected by humidity, temperature, light, and wind. Low humidity and higher temperatures generally increase the rate of transpiration by enhancing the vapor pressure gradient and kinetic energy of water molecules, respectively. However, at extreme temperatures or under water stress, stomata may close, reducing transpiration.
Step-by-step explanation:
Environmental Factors Affecting Transpiration
Transpiration in flowering plants can be affected by various environmental factors such as humidity, temperature, light intensity, and wind speed. For example, humidity has a significant impact on transpiration rate. When the air is dry (low humidity), it increases the concentration gradient between the water vapor inside the leaf and the atmosphere, which leads to a higher transpiration rate. Conversely, high humidity levels result in a lower gradient and a slower transpiration rate.
Temperature is another critical factor influencing transpiration. As temperature rises, it can increase the kinetic energy of water molecules, causing them to vaporize more easily. However, when the temperature gets too high, transpiration rates may level off or decline. This happens because the stomata may close to prevent water loss in extreme conditions, thus reducing the rate of transpiration.
Daylight also influences the opening and closing of stomata; during the day, when photosynthesis occurs, stomata are generally open, but they close at night. Water stress is an additional factor, as it triggers the production of the phytohormone abscisic acid (ABA), which leads to stomatal closure to conserve water, thereby affecting transpiration.