x Abu Dhabi, UAETuesday 25 July 2017

An ancient encore

Ample rains have lured a rare and spectacular bloom back to the Wadi Shahah basin - opulent displays of rich colours that are thousands of years old.

Pink mustard flowers fill the landscape of Wadi Shahah. Satish Kumar / The National
Pink mustard flowers fill the landscape of Wadi Shahah. Satish Kumar / The National

‘Seven years ago this happened,” says Barbara Couldrey, wading through a knee-high field of flowering pink mustard in Ras Al Khaimah. “I call it the seven-year itch.”

Wadi Shahah, normally a basin of dull browns, is awash in delicate purple blossoms of mustard flowers (Erucaria hispanica), the air fragrant with their perfume.

Couldrey strides through the wadi as if showing off her home, presenting budding peas and yellow daisies. She has hiked these mountains thousands of times over two decades. She knows where to find flowers and when.

“Now that’s sorrel. This you can eat. Put it in your sandwich,” she says, handing out the lemon-flavoured leaf. “See, this is where there are little dells where this really grows. At the moment there are grasshoppers around. Big ones.”

The wadi bloom is a rare but regular occurrence. Every so often, after a season or two of heavy and well-timed rains, the Ru’us Al Jibal mountains reveal a technicolor display of geraniums, poppies, thick grasses and cascading vines.

The base of Ras Al Khaimah’s Wadi Shahah looks like the landscape of a Persian miniature, flush with tiny violet cat’s eyes and deep blue pimpernels with dotted yellow centres.

“Nature, it comes and goes,” says Couldrey. “You don’t know when it’s going to come. Nature has a will of its own. Maybe itching to come out. Waiting for the rain.”

The Ru’us Al Jibal range, which includes the Omani exclave of Musandam and the adjoining mountains of Ras Al Khaimah and Fujairah, rises from the gravel flats north-east of the Empty Quarter. It is part of the Hajar mountain range parallel to the Gulf of Oman.

The Ru’us Al Jibal is home to 338 species of wildflowers and plants that spring from rolling plateaux and sheer cliffs. Its plant life bears more resemblance to that of the Iranian plateau than anything in Arabia — fields of lilies, pale pink almond blossoms and forget-me-nots in hues of red, yellow and deep blue.

Rainfall awakens wildflower seeds that lay dormant for years, even decades. The mountains average 190 millimetres of rain a year, but this varies from 80mm to 450mm. Summer rain is rare. Snowfall occurs about once a decade.

Heavy rainstorms, like those experienced this winter, trigger imperceptible movements that transform parched wadis beyond recognition. Mechanics take over as plants prepare to sprout. Filaments unwind like tightly coiled springs, pushing seeds into the earth or popping seeds metres away to maximise dispersal.

The vegetation of the Ru’us Al Jibal is unique in eastern Arabia, geographically and geologically distinct to the mountains farther south.

Its sedimentary mountains, flat-topped and steep-sided, are folded layers of limestone and dolomite, originally deposited in shallow seas that gradually rose 3,000 metres in the last 30 million years.

South of Tawaeen, Hatta and into Oman, the mountains transform into ophiolite, igneous slabs of the Earth’s oceanic crust thrust to the surface by plate tectonics. The emirates and Oman have the largest surface exposure of ophiolite rocks in the world.

In most countries, ophiolite is associated with unusual plant communities due to inhospitable alkaline groundwater and heavy metal content. In the Hajar Mountains, where ophiolite is more common than limestone landscape, scientists have only just begun to link plant communities with the Ru’us al Jibal geology.

About 75 of the 338 Ru’us Al Jibal plant species are only found in this corner of Eastern Arabia, being absent from the ophiolite mountains farther south.

“Plants are making choices,” says Gary Feulner, the author of a comprehensive paper on Ru’us Al Jibal flora. Feulner, a geologist turned lawyer, made more than 120 excursions in the Ru’us Al Jibal between 1991 and 2011. He began by recording plant descriptions and locations into his Dictaphone.

“It’s the Sherlock Holmes case of The Dog That Didn’t Bark,” says Feulner. “You’re jotting down what you see and then you realise what you didn’t see and you start looking and thinking, ‘what’s going on here?’ The plants are responding to different environments. Some that you see within the ophiolite you just don’t see within the Ru’us Al Jibal.”

Wildflowers vary tremendously with rising elevation as temperatures drop and precipitation increases.

“Confirming the general principle that going uphill is like going north, many of the species of the high Musandam are not found elsewhere in the UAE, but they can be seen at more northerly latitudes such as northern Saudi Arabia or Kuwait,” says Feulner. “There are high elevation annuals, like gladiolus and buttercups, that you’d find on a desert plain out in northeastern Saudi.”

Feulner’s examples include aromatic sagebrush (Artemisia sieberi), a spiny morning glory bush (Convolvulus acanthocladus), the Arabian almond (Prunus arabica), citronella grass (Cymbopogon jwarancusa) and a spiny milkvetch with inflated pink seed pods (Astragalus fasciculifolius).

Common species are living evidence that during the Pleistocene epoch, 2.6 million to 11,700 years ago, the emergent Gulf was a broad extension of the Tigris-Euphrates watershed. Plants and animals moved freely between Iran and Arabia.

Even earlier, plant life evolved from tropical vegetation of Africa and western Arabia, 50 to 25 million years ago, before the Red Sea separated Arabia and Africa.

Today’s species are relics of a more abundant and diverse plant life, lone survivors of an era when the Ru’us Al Jibal offered a wetter, cooler climate. Species at high elevations that struggled with increasing aridity or warming could not climb farther and died out.

The current flora of the Hajar Mountains, including the Ru’us Al Jibal, was likely established in the last 5,000 to 6,000 years when the climate began to resemble what it is today.

Documentation of the Ru’us Al Jibal’s existing species is largely the work of Marijcke Jongbloed, the former director of Sharjah Desert Park and a founding member of the Arabian Leopard Trust. She is now living in France.

An amateur botanist, Jongbloed started collecting in 1983, gathering any and all plants in her path on her mountain wanderings. She partnered with Loutfy Boulos, a botany professor she met at the Royal Botanic Gardens. The Egyptian botanist taught her to dry and mount specimens. Jongbloed collected and shipped them to him for identification.

The result was her 2003 encyclopaedic work, The Comprehensive Guide to the Wild Flowers of the United Arab Emirates.

“There were absolutely no books about botany at that time. I just recorded every single plant I saw,” she says. “I didn’t know any of the plants so everything was new.

“I just kept on collecting. You get addicted to it.”

She reels off a list of favourites: the caper bush (Capparis spinosa), with its large, white blossoms and feathery purple stamen and the delicate blue pimpernel flowers (Anagallis arvensis).

“In Dutch it’s called guicheil and it means that it heals you when you’re insane, and I can imagine that because when you look at it you’re so happy you haven’t got time to be insane.

“Every single plant is beautiful and special, and I also very much learnt to appreciate the grasses, which I never even looked at in Europe. What’s so nice about botanising in [the wadis] is that the plants all stand on their own. So you can see what their shape is and you sort of notice their flowers and shapes more easily.”

Given the heavy rains experienced this year, the wadi bloom is expected to continue into May. Blossoms change week by week and according to elevation. Many are easily accessible by road, if people take the time to stop.

“People go through areas at a speed that doesn’t show them anything of the beauty of the desert,” says Jongbloed. “Basically the only ones who can enjoy it are the ones who are climbing to the tops of the mountains.”

azacharias@thenational.ae