The secret behind spectacular blooms in world’s driest desert: The Atacama desert, which stretches for approximately 1,600 km along the western coast of the cone of South America, is the driest place on Earth. Some weather stations there have never recorded rainfall throughout their existence. But it’s far from barren: many species live here that occur nowhere else, adapted to its extreme conditions. Every 5 to 10 years, from September to mid-November, the Atacama hosts one of the most spectacular sights of the natural world: the “desierto florido” (literally “blooming desert”). These mass blooms, one of which is currently going on in the northern Atacama after abundant rainfall earlier this year, often attract media attention from around the globe.
But what mechanisms enable the great diversity of flower colors and shapes? And how do pollinators—in the Atacama, mainly solitary wasps and bees—for whose benefit this visual extravaganza evolved, perceive all this variation? That’s the subject of a new study in Frontiers in Ecology and Evolution. “Our aim was to shed light on the ecological and evolutionary mechanisms that cause biological diversity in extreme environments like the Atacama desert,” said first author Dr. Jaime Martínez-Harms, a researcher at the Institute of Agricultural Research in La Cruz, Chile. “Here we show that flowers of the pussypaw Cistanthe longiscapa, a representative species for desiertos floridos in the Atacama desert, are highly variable in the color and patterns they present to pollinators. This variability probably results from different so-called ‘betalain’ pigments in the flower petals.” Martínez-Harms and colleagues studied a desierto floridoevent in late 2021 near the city of Caldera in northern Chile. Despite being smaller in size than the event currently going on, it was clearly visible to satellites.
Using cameras sensitive to both visible and UV light, and spectrometers to measure the reflection, absorption, and transmission of different wavelengths by different colours of flowers, the scientists determined that the colour variation visible to local pollinators is much more diverse than what we humans see.
Fragrant Harvest: In late spring, the bees arrive at Joseph Mul’s fields near Pégomas, France, at around nine-thirty each morning. The unmarked fifty acres border a gravel path, which veers off a country road that cuts through a sheltered valley. To the northeast, one can make out the dark-blue mounds of the pre-Alps. A tickly breeze blows in from the Mediterranean, a few miles to the east. For non-pollinators, the site is almost impossible to find. This is intentional, as, since the mid-nineteen-eighties, the Mul family has had an exclusive partnership to grow jasmine and roses for Chanel. The company uses the flowers to make Chanel No. 5—a perfume that, in the way of a Cavaillon melon or a piece of Sèvres porcelain, comes from a specific place. The species is prized for its clear, sweet, honeyed scent. If it were a musical instrument, it might be a flute. It is so distinctive that Joseph Mul, whose great-grandfather started the farm in the early nineteen-hundreds, can identify a rose grown in Pégomas with his eyes closed. “You can compare it to wine,” he said recently. “A Burgundy from anywhere else isn’t a Burgundy.” When the roses bloom, the entire fifty acres must be harvested in two weeks. Mul works with his son-in-law, Fabrice Bianchi, to supervise a crew that comprises seventy pickers (mainly Turkish women, many of them related) and four videurs (mainly French men, into whose burlap sacks the women empty their aprons). They were expecting to haul in thirty-seven tons of flowers. This gorgeously illustrated article answers the question: How many roses go into a bottle of Chanel No. 5?
Gardening at Last 