Gaseous Exchange in Woody Plants
Woody plants primarily carry out gaseous exchange through specialized structures called stomata. These are small openings located mainly on the leaves but can also be found on stems and other green parts.
Stomata and Their Function
- Definition: Stomata are microscopic pores surrounded by guard cells.
- Location: Predominantly found on the leaf epidermis.
- Function: Facilitate the exchange of gases, allowing carbon dioxide (CO2) to enter for photosynthesis and oxygen (O2) to exit as a byproduct.
Role of Guard Cells
- Regulation: Guard cells control the opening and closing of stomata.
- Response to Conditions: They respond to environmental factors like light, humidity, and CO2 concentration.
- Water Conservation: Closing stomata during dry conditions helps prevent water loss.
Other Mechanisms of Gaseous Exchange
- Lenticels: In addition to stomata, woody plants have lenticels, which are small openings in the bark that facilitate gas exchange in stems.
- Photosynthesis and Respiration: Gaseous exchange is crucial for photosynthesis during daylight and respiration throughout the day and night.
Importance of Gaseous Exchange
- Photosynthesis: Essential for converting light energy into chemical energy.
- Respiration: Provides energy for growth and development.
- Environmental Interaction: Helps maintain ecological balance by regulating atmospheric gases.
In summary, woody plants utilize stomata and lenticels for effective gaseous exchange, crucial for their survival and interaction with the environment.

Lenticels