Why Driest Desert on Earth Sometimes Blooms? And What Secrets Reveals?
In one of the driest places on earth, the Atacama Desert, a flower blanket occurs every time the right amount of rainfall and temperature come together to awaken long-dormant seeds. This phenomenon generates an entire ecosystem of insects, reptiles, and birds that need to be protected. Our home editor, Nicole Saffie, experienced this phenomenon in first-person during 2021.
photo_camera The desert bloom is a phenomenon associated with rainfall events, especially in "El Niño" years, when temperatures are warmer. Although it occurs more frequently in the area of Copiapó, Huasco and Caldera, in the Atacama region, it can also be seen in certain locations in the Antofagasta region, with less frequency but greater diversity and endemic species. Desert bloom in the Atacama region/Nicole Saffie
Fifteen millimetres is the approximate minimum amount of water required by the dormant endemic seeds of the Atacama Desert to bloom. They also need warmer temperatures and precise lighting conditions.
When the conditions are perfect, the driest desert in the world is transformed into a real garden.
As explained by María Fernanda Pérez, professor at the Faculty of Biological Sciences, “The flowering desert is a phenomenon associated with rainfall events. There is a plant biomass increase, which is primarily due to herbaceous plants.”
Desert blooms become more diverse and extensive as more water falls.
“Like the one in 2017, which was spectacular; 50 mm of rain fell,” she added.
“This blooming coincides with El Niño currents, during which temperatures are warmer, resulting in more evaporation and, consequently, more rainfall. But not with La Niña current, which is colder," added Ana María Mujica, a professor at the Faculty of Agriculture & Forestry.
"Over the past 40 years, about fifteen events have taken place. This happens in the area of Copiapó and Huasco, in the third region of Atacama, but there are other very important areas in terms of diversity and endemic species, such as Paposo, in Antofagasta, and near Iquique. Here, rainfall is lower and much less frequent. This region has a high degree of endemism, meaning that species that are only found in this region are very, very important."
In 2021, rainfall was around 10 mm in the Copiapó area. Although it was scarce, it allowed the flowering desert to occur, especially inland and in the vicinity of Caldera. Regardless, it is impressive.
On the Flower Route
I travel along Route 5 North, on the stretch that goes from Copiapó to Vallenar. I can only see dry plains and hills, without even a cactus in sight, just land and a deep blue sky without any clouds. Most of the vehicles on the highway are from the mining industry, the region's economic activity par excellence.
Suddenly, almost at the C-35 junction that leads to the town of Nantoco, the landscape begins to take on a slightly lilac hue until the colour becomes an intense fuchsia thanks to a real blanket of rock Purslanes (Cistanthe grandiflora) that covers the entire plain and the hills, as far as the eye can see.
As I get closer, dots of different colors appear:
- yellow and orange Añañucas (Zephyranthes bagnoldi),
- Suspiros de campo blanco (Nolana baccata),
- Suspiros (Nolana carnosa and Nolana acuminata),
- Malvillas (Cristaria sp.)
- And Coronilla del Fraile (Encelia canescens), among others.
Sleeping Beauty Seeds
As Ana María Mujica, who has been studying desert plants for over 30 years, explained, all the flowers have a common characteristic.
They are herbaceous—or grasses, species that grow from seed, have stems, leaves, and flowers—and are classified as annual plants, that is to say, in the span of a year (generally 3 to 6 months) they germinate, flower, bear fruit and die, leaving the seeds for the next generation.
These seeds are composed of an embryo, which is nourished by starch and covered externally by a very hard and almost impenetrable coat. "This allows the seeds to spend 5, 7 or even 10 years in a latent or dormant state", said the professor. They are little sleeping beauties.
There are other species, such as herbaceous biennials - which develop their entire life cycle in a period of two years - bulbs, rhizomes and corms, which are underground nutrient storage organs, such as lilies.
"An impenetrable coat allows the seeds to spend 5, 7 or even 10 years in a latent or dormant state." - Ana María Mujica
The variety is huge.
The flowering desert is composed of 1,893 plant species, of which 32% are endemic to this part of South America and 58% are endemic to Chile (according to a study by the Instituto de Investigaciones Agropecuarias, 2017).
Furthermore, it is believed that there are still many that have not been discovered.
In Search of Cacti
Cacti are typical in this area and the so-called Copiapoa is, without a doubt, the 'golden star' of the region. This is a cactus native to the dry desert coast of northern Chile, comprising about 26 species. Although they vary in shape, they are characterized by being rather spherical. Their color ranges from brown to blue-green.
The Llanos de Challe National Park, on the Atacama coast, is a true refuge of the Copiapoa de Carrizal (Copiapoa dealbata). It grows like a real cushion, reaching up to 1 meter high and 2 meters wide.
They are covered in a whitish wax that protects them from dehydration, and their yellow flowers appear like a miracle among thorns, that shield them and prevent evaporation.
Unfortunately, its conservation status is vulnerable, due to its extremely restricted geographic distribution and declining reproduction (Check out the “Threatened Flora of the Atacama Region and Strategies for its Conservation” Guide).
In addition, there is also illegal trafficking of cacti.
Copiapoa is a highly desirable species in European and Asian markets, where a plant can be sold for 500 to 1,500 dollars.
A Little Water to Awaken the Desert
The flowering desert is a very particular ecosystem.
According to Ana María Mujica: “It is an ephemeral flowering, very short-lived, around which arises numerous species: birds, insects, reptiles, rodents. It's all related.”
In fact, "The diversity of insects is spectacular, there are some species that are only found in the flowering desert", said María Fernanda Pérez. "All it takes is a little water to awaken an entire ecosystem."
The pollination of many of these species is essential for maintaining the viability and genetic diversity of plants and improving seed quality and quantity.
They also move seeds from one place to another, expanding the geographical location of the species.
Given its particular characteristics, the flowering desert is a fragile ecosystem. Pulling up a plant or extracting seeds can cause them to disappear forever.
The same applies to the use of motorcycles and vehicles that travel off the trails and into the flowered hills. Other factors include soil erosion, mining and industrial activities, livestock, and climate change.
Both scientists emphasized the importance of education.
"I believe people need to know about the flowering desert first. Second, we need to educate people about it. Third, we need to preserve. And finally, we need to take conservation measures, such as laboratories and gardens, to preserve and reproduce seeds so that the species can continue to exist."
"I think if people knew that a bulb could be fifteen to twenty years old, they wouldn't take it out. The same with cacti. In addition to learning what these species mean to the ecosystem," said María Fernanda Pérez.
“We have to revalue our natural history.”
