Cactus can survive and thrive in extreme desert conditions, but have you wondered how does a cactus survive in the desert with arid, dry conditions? Well, the answer lies in the exotic appearance of the cactus.
Tiny leaves, spines, and succulent stems all make the cactus adaptable to the arid climate of the desert.
How does a cactus survive in the desert?
Some of the features which allow the cactus to survive such a harsh climate are –
- Waxy Skin
- Succulent Stems
- Tap Root System
The most identifiable feature of the cactus is its thorny spines. They reduce the surface area of the plant that causes the plant to lose less water through evaporation.
The spines also have a hierarchical groove structure which helps them collect water. It also provides added protection against predators that helps reduce the chances of wounding.
Thus, less water is used for healing. Further, the spines of the cactus form buffer air traps that help restrict moist air around it. It helps the cactus reduce loss of moisture through evaporation.
2. Waxy Skin
The cactus has a waxy coating on its skin. This coating covers most of the cactus apart from the stomata. It helps in the retention of moisture in the cactus and prevents it from drying out. Thus, allowing it to survive for longer periods with minimal water requirements.
Further, the wax also helps keep the plants cool in the hot climate and reduces the chances of damage due to sunburns caused by exposure of the cactus to long hours of direct sunlight.
3. Succulent Skin
The cactus uses its thick, succulent stem as a reservoir for water retention. The stems can expand when it needs to store extra water for the drier days. Since rains in the desert are sporadic, it allows the plant to store large amounts of water and survive for longer durations. Further, the spherical shape of the stem helps reduce surface area, essentially reducing the area exposed to direct sunlight. It reduces evaporation and helps save water.
4. Shallow Root System
The cactus has a shallow tap root system which allows the plant to quickly absorb the water from the ground. It is integral as the sand in the desert is usually porous, which means the water seeps down very quickly.
Similarly, the heat causes faster evaporation of water from the ground. Additionally, the cactus roots extend to a wide area, allowing them to cover more ground. It enables the cactus to quickly absorb the water before it evaporates into the air or seeps down to the ground.
Since evaporation is one of the primary causes of water loss, the cactus only carries out an essential part of the photosynthesis at night. The stomata open up only during the night and close at dawn. Thus, the plant essentially photosynthesizes during the day, but only the gases are exchanged at night. The temperatures are much cooler at night, and hence the water loss is lesser. This type of photosynthesis is named “Crassulacean Acid Metabolism (CAM).”
So, these are the features that allow the cactus to survive in the harsh, and dry conditions of the desert.