What are some examples of leaves adapted to high light intensity?

Examples of leaves adapted to high light intensity include those of cacti, succulents, and some alpine plants.

Cacti, succulents, and certain alpine plants have evolved specific adaptations to cope with high light intensity. These adaptations are primarily structural and physiological, aimed at reducing water loss and protecting the plant from harmful ultraviolet (UV) radiation.

Cacti, for instance, have small, spiky leaves that reduce the surface area exposed to the sun, minimising water loss through transpiration. They also have a thick, waxy cuticle that reflects sunlight, reducing the amount of light absorbed and thus the potential for damage from UV radiation. Additionally, cacti have evolved to carry out photosynthesis in their stems rather than their leaves, further reducing their exposure to high light intensity.

Succulents, like cacti, have thick, fleshy leaves that store water. These leaves often have a waxy or hairy coating that reflects sunlight, reducing light absorption and the risk of UV damage. Some succulents also have the ability to change the orientation of their leaves to avoid direct sunlight, a phenomenon known as paraheliotropism.

Alpine plants, which grow at high altitudes where light intensity is high, have also developed adaptations to cope with these conditions. Many have small, narrow leaves that reduce the surface area exposed to the sun, minimising water loss and the risk of UV damage. Some alpine plants also have leaves that are covered in hairs or scales, which reflect sunlight and provide a degree of insulation against the cold.

In summary, these adaptations help plants survive in environments with high light intensity by reducing water loss, minimising exposure to harmful UV radiation, and in some cases, altering the way they carry out photosynthesis.