1. Plant Adaptations

2. What do plants need?
Light
Water
Space
Nutrients
Warmth

3. Why do plants need water?
Photosynthesis
Support
Transport

4. Transpiration
Plants take in water from the roots and lose water from the leaves. Water moves up plants in the transpiration stream.
Leaves have small holes called stomata to allow gases (oxygen and carbon dioxide) to enter and leave the leaves. Water vapour also escapes through the stomata.

5. Stomata
The guard cells change shape to open and close the stomata. When conditions are dry the plant closes the stomata to reduce water loss

6. Rate of Transpiration
Plants lose water more quickly in dry and hot conditions e.g. deserts. Plants that live in dry and hot conditions have adapted to reduce their water loss.

7. Reduced Leaf Surface Area
A reduced surface area to volume ratio reduced water loss.
Cacti have reduced their surface area by losing their leaves. Have spines instead. This also prevents animals from eating them.

8. Reduced Leaf Surface Area
Marram grass which lives on sand dunes has reduced its surface area by having its leaves rolled inwards to trap a layer of moist air
The stomata are on the inside here it is more moist and so less water is lost

9. Cross Section of Marram Grass

10. Root Systems
Cacti often have very shallow roots that spread out widely. This means they can catch water as soon as it rains.
Other plants may have very
deep roots

11. Water Storage
Some plants known as succulents store water inside fleshy stems leaves
or roots

12. Other plant adaptations
Some desert plants have broad leaves to catch the dew in the evenings. This is then funnelled into their root systems
Some desert plants have fleshy leaves with a thick cuticle to prevent evaporation
Some plants break down insect’s bodies to release minerals