It's in your nature
Even the cacti will get too hot
Audio 03:29
60% of cacti are threatened by global warming.
© Pixabay / Mikes Photography
By: Florent Guignard Follow
2 mins
On the eve of the opening in Abidjan of COP15, the world summit against desertification, a close-up of the kings of the desert: cacti.
Even those plants that are not afraid of drought are threatened by global warming.
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It's a western setting, when the sun is blazing.
The only shadow in a landscape of stone and dust, when all forms of life seem to have disappeared, the cactus remains standing.
It is a plant from America, which crossed the Atlantic thanks to migratory birds.
There are more than 1,500 species of cacti in the world, and it is in Brazil and Mexico that there are the most.
Plants with a thousand shapes so fascinating that you want to touch them.
But whoever rubs it gets offended.
Cactus spines repel predators.
And to make it hurt even more if you want to remove it, the needle is covered in microscopic, sharp scales pointing in the opposite direction to the tip.
Thorns, moisture sensors
But these thorns have other virtues.
They allow the plant to capture moisture at night.
The water in the air condenses on the tip, forms a drop, which eventually drains away.
Engineers specializing in biomimicry are trying to draw inspiration from it for the benefit of humans.
For cacti, everything happens at night, when the aggressive sun has set.
The stomata, these small holes that allow plants to breathe, closed during the day to avoid evapotranspiration, open at nightfall to capture CO2.
90% of cacti threatened
The sun, here is the enemy, and especially the absence of rains.
Cacti are the kings of the desert, and to live there they had to adapt, becoming xerophytic, like succulents, succulents, capable of surviving weeks and even months without a drop of water, storing the rain when it falls.
Only then, the cacti themselves are not spared by global warming.
Spontaneously, one would think that they would thrive with rising temperatures.
But even cacti will get too hot, and many could disappear, according to a recent study published by the University of Arizona in the United States: 60% of cactus species are threatened, and the figure rises to 90% in 2070 if we add agriculture and urbanization.
Global warming sucks.
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Also to listen: What challenges for COP 15 desertification?
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To read also: Desertification is gaining ground but solutions exist
THE QUESTION OF THE WEEK
“What does it feel like if I bite into a cactus? »
It hurts !
But that's not the case for everyone.
Several desert animals enjoy it, often for lack of anything better: iguanas, peccaries, these little American pigs, or even camels thanks to the keratin on their taste buds.
The United Nations also encourages the use of cacti to feed farm animals.
But even humans can eat it.
The nopal, the prickly pear, was appreciated by the Aztecs, for food, for treatment.
It even appears on the flag of Mexico.
A nutritious and very low calorie plant.
Know this, succulents will not make you fat.
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