Rate of transpiration

• Light intensity:

  • the brighter the light, the greater the transpiration rate
  • Stomata being to close as it gets darker, photosynthesis can't happen in the dark, so they don't need to be open to let CO2 in. When the stomata are closed, very little water can escape
• Temperature:

  • the warmer it is ,the faster transpiration happens
  • when it's warm the water particles has more energy to evaporate and diffuse out of the stomata
• Air flow:

  • the better the air flow (wind) around a leaf, the greater transpiration
  • if air flow is poor, water vapour surrounds the leaf and doesn't move away. This means there's a high concentration of water particles outside the leaf and inside it, so diffusion doesn't happen quickly
  • If air flow is good, water vapour is swept away - low concentration of water in the air outside the leaf. diffusion happens quickly
• Humidity:

  • the drier the air around the leaf, the faster transpiration happens
  • if air is humid there's a lot of water in it already, so there's not much of a difference between the inside and outside of the leaf