Why do cactus have thorns?

 

Most cacti live in barren desert areas. Desert areas have a lot of sand. It's very hot and dry during the day. It is chilly and cold at night. The daily temperature difference is very severe and water is very scarce. This article introduces how cactus adapted to this environment.

 

The role of thorns

1. Protecting against predators

• The cactus's thorns are basically protected from predators. Cacti develop thorns so that herbivores cannot chew cacti well. 
• But some herbivores do not find thorns difficult. Herbivores chew cacti even if they have thorns. 

2. Maintaining stem temperature

• The dense spines of the cactus act as a shade. In other words, it blocks the temperature of the stem from rising.
• The thorn disturbs the sunlight and blocks the sunlight from entering the stem.

3. Collecting moisture from the air

• Cactus collects water by absorbing moisture in the air with thorns.
• The thorns collect dew and let it fall into the soil under the cactus. And roots help you drink water.
• In particular, in the desert, fog often occurs in the morning, and at this time, thorns help to hold dew. 

4. Preventing water from evaporating

• The cactus made its leaves into thorns to prevent water from evaporating. 
• Water is converted into water vapor through stomata and the water escapes from the plant body.
  
• In particular, the thinner and wider the leaf, the easier it is to evaporate the water. Thin leaves try not to store much water in the leaves. In addition, when the leaves are wide, the surface area where the leaves receive sunlight increases, and water evaporates easily. Cactus thorns minimize evaporation by minimizing the surface area.
• The spines of the cactus slow down the air flow around it. It serves to trap moisture.

 

Cactus is an excellent survivor!!

 

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Important thing & Reference thing 

 

1. The characteristics of plants with thin and wide leaves

• Plants with thin and wide leaves should be watered frequently when growing plants. In other words, it is a plant that consumes too much water.
• The native habitat of thin-leaved plants is a humid and water-rich area. Water can be consumed at any time without storing water in the leaves, so there is no need to store it.
• These plants are very difficult (or different from my lifestyle) to grow in a normal plant nature, so I avoid growing them.

2. Meaning of plant stomata

• It is a hole in the outer shell of a plant leaf or stem, and is mainly located behind the leaf. Plants breathe and evaporate water through these holes.

3. Transpiration

• It refers to a phenomenon in which water escapes to the outside by steam through pores.
• When water is released, it plays a role in raising water from the root to the top of the plant to make up for the lack of water. Through this act, the temperature and moisture of the plant are controlled. In addition, plants try to maintain homeostasis while controlling inorganic nutrients.
• In particular, the transpiration is most common when the amount of water in the plant body is high, the sunlight is strong (=temperature is high), the wind blows well, and the humidity is low.

Pictures of cactus in Jeju