How has hot desert vegetation adapted to the climate?

The extreme climate of the desert ecosystem means that plants and animals have had to adapt to survive. Vegetation has had to adapt to the extreme temperatures, lack of water and high rates of evaporation.

The main adaptations are:
• Vegetation has leaves that are very small (and only grow after it rains) or have no leaves at all. This helps to reduce water loss;
• Plants either have long root systems spread out wide or go deep into the ground to absorb water;
• Plants have short life cycles. They germinate following rainfall, grow, flower and die within a short space of time e.g. one year. This helps them avoid drought;
• Some plants have spines to discourage animals from eating plants for water and reduce water loss through transpiration;
• Many plants are slow-growing – this requires less energy. The plants don’t have to make as much food and therefore do not lose as much water.

Some plants are succulents and store the water in their leaves, stems or roots. An example of this is the cactus.

The needles on a cactus reduce water loss by transpiration

Cacti also have spines instead of leaves. These minimise surface are and helps reduce moisture loss through transpiration during the day. The spines also protect the cacti from being eaten by animals. They also have a waxy coating on stems to help reduce water loss.

Cacti have widespread root systems, located close to the surface that can collect water from a large area.

Other ways plants tolerate the dry conditions include:

long roots to tap into the water deep underground
short life cycles – a plant or seed could remain dormant until the rains come