How Do Cacti Survive?
As we all know, cacti live in deserts. But how do they survive in such hot, dry conditions? Cacti have an amazing feature of storing as much water as possible over long periods of time in their shallow, short roots and wide stem. The stem of a cactus is the major storage section for water that has a waxy surface, which helps retain moisture and does not allow water to evaporate. As you might remember, cacti are leafless! They adapted to the hot, dry environment of deserts and developed spines that provide some shade for cacti, which keeps them cooler and prevents water loss. These spiky spines also help them defend themselves against large animals that want to eat them! What about small creatures that cacti would need to be protected against? They produce special nectar to attract ants that help keep away small bugs and other pests. Ants gladly do so since there are not a lot of options for food and water in the desert!
Like all plants, cacti perform photosynthesis, which is the process of converting carbon dioxide and water into glucose and oxygen using energy from sunlight. However, an interesting thing about cacti is that they do it at night! All plants have special pores called stomata that can open in order to take in carbon dioxide and start the process of photosynthesis. During this process, plants lose a lot of water to produce glucose molecules that they can use for energy. During the day in the desert, water loss can be very high due to extreme heat. That is why cacti open their stromata at night when temperatures are cooler to reduce the water loss. They take in and store carbon dioxide during the night and perform photosynthesis during the day to make glucose and use its energy to maintain their functions. During summer, when temperatures in deserts are especially high, cacti close their stromata completely, preventing glucose production and, therefore, their own growth.
Cacti are amazingly built to survive in such hostile conditions, which makes them very interesting to learn about!
