An Nafud Desert
The An Nafud Desert, also known as Al-Nafud, is a prominent erg located in the northern Arabian Peninsula, specifically within Saudi Arabia. Covering an area of approximately 40,000 square miles (103,600 square kilometers), it features an oval shape that extends 180 miles (290 kilometers) in length and 140 miles (225 kilometers) in width. Characterized by its predominantly hot and arid climate, the desert experiences extreme temperature fluctuations, with summer highs often exceeding 100°F (38°C) and winter lows dipping just above freezing at night.
Despite its harsh environment, the An Nafud Desert supports some life, particularly around its oases where a limited variety of vegetation flourishes, including saltbush and various grasses that adapt to the sandy landscape. Wildlife in the region includes species such as gazelles, ostriches, and sand cats, which have adapted to survive with minimal water. The desert's unique geology includes a limestone floor, which has been shaped over millions of years by wind and water, creating features like quicksand and caves. Additionally, the western oases offer a more hospitable climate, supporting a wider range of crops and wildlife, making them vital for both local flora and fauna as well as for the nomadic Bedouin communities that inhabit the area.
Subject Terms
An Nafud Desert
- Category: Desert Biomes.
- Geographic Location: Middle East.
- Summary: The An Nafud Desert is a windswept erg (dune sea) in the northern Arabian Peninsula, with limited biodiversity except in its oases.
The An Nafud or Al-Nafud Desert is in the northern Arabian Peninsula and is considered to be part of the Arabian Desert. It comprises a 40,000-square-mile (103,600-square-kilometer) oval depression across northern Saudi Arabia, and is 180 miles (290 kilometers) long and 140 miles (225 kilometers) wide.
Rainfall is extremely variable and unpredictable, with total annual precipitation typically less than 2 inches (50 millimeters), though as in all deserts, the climate is predominantly hot and arid, turning cold at night because there is so little vegetation to retain heat. Winter temperatures see the greatest diurnal difference, ranging from just above 32 degrees F (0 degrees C) at night to about 70 degrees F (21 degrees C) during the day. Summers often have lows of 80 to 89 degrees F (27 to 32 degrees C) at night and exceed 100 degrees F (38 degrees C) during the day.
Like the Arabian Desert's other major components, the Dahna and the Rub' al Khali to the south, the Nafud is an erg, a flat or depressed area with scant vegetation and particularly identified as a sea of dunes or sand sea. The term erg is from the Arabic 'arq or dune field. Along with those of central Asia, the Nafud is one of the oldest ergs in the world, formed by the wind over a period of at least 1 million years. The sand has a red or rusty hue; the wind forms wavelike undulations across it that each may stretch for miles.
Like much of the Arabian Peninsula, the Nafud lies atop a limestone floor riddled with caves and passageways formed by the ancient and ongoing percolation of rainwater, which has absorbed carbon dioxide and formed a weak carbonic acid capable of eating away at the limestone in minuscule amounts at a time.
Though quicksand is not as common as in Rub' al Khali, it does exist in the Nafud, though it is not the suffocation hazard that it is portrayed to be in motion pictures. Quicksand forms when an area of loose sand becomes saturated with water (such as from an underground spring), creating a non-Newtonian fluid that appears to be solid until a change in stress (such as being walked upon) decreases its viscosity. Animals do not become submerged in quicksand, but attempting to withdraw from it at anything but incredibly slow speed requires force comparable to that necessary to lift a horse.
Desert Vegetation and Wildlife
Springtime in the Nafud, after the extremely light seasonal rains, turns portions of the desert into grassy areas sufficient for pasturing by the nomadic Nejd Bedouins and provides foodstuffs for the indigenous wildlife. Saltbush (Cornulaca arabica), Calligonum crinitum, and Cyperus conglomeratus are among the most common plant species in the Nafud. Dipterygium glaucum, Limeum arabicum, and Zygophylum mandavillei sometimes occur. Certain local herbs, such as Danthonia forskallii, also grow after a rainfall. Sand, however, dominates the landscape, making it difficult for things to grow. Desert vegetation have adaptations that allow survival in the landscape. One notable adaptation is the rapid elongation of stems and roots of plants to keep reproductive and photosynthetic organs above changing sand levels. The scarcity of vegetation in the Nafud diminishes potential biodiversity, so there are no formal protected areas in the desert.
Wildlife includes gazelles, which according to popular belief never need to drink, though in fact they are simply desert-adapted and highly efficient in their water use. Ostriches, rodents, spiders, hares, sand cats, spiny-tailed lizards, and oryxes are also well adapted to the extreme environment of the Arabian deserts and appear all over the peninsula. Other species once common here—such as the honey badger, the Arabian ostrich, and the jackal—have become rare or extinct due to hunting and habitat destruction. An endemic (existing here only) species is the bakkar vanash (wild cow), a species of humped antelope.
The harvester termite is widely distributed throughout the Arabian Peninsula. Although the Nafud's sparse vegetation makes it less hospitable to the termite, the insect nevertheless lives here, though with few human settlements to threaten, it is less of a pest. The termite can feed not only on dry weeds and tree stumps, but also on the cellulose in (herbivorous) animal droppings, windblown accumulations of plant debris, and other samples of decomposed flora.
Western Oases
Near the Al Hejaz Mountains in the west are low-lying oases; here some crops are cultivated including fruits like dates and grain such as barley. Wildlife is also more plentiful here, and the climate is less arid. A single oasis has considerably more diversity than the rest of the Nafud. Migratory birds are more common in the mountains, which are relatively cool, yet many of the swifts, larks, wheatears, and other species stop in the desert oases to drink and forage. Raptors also visit sometimes, as well as bustards, sandgrouses, and chukar partridges. Reptiles in the oases include spiny-tailed lizards (Uromastyx thomasi) and monitor lizards (Varanus grisens).
The oases are home to many of the acacia trees that grow elsewhere in the Arabian Desert, including Acacia tortilis, A. raddiana, A. gerrardii, and A. ehrenbergiana. Ziziyphus spina-christi, Balanites aegyptiaca, Salvadora persica, Moringa peregrina, Capparis decidua, Cordia gharaf, Calotropis procera, Lavandula nubica, and Ephedra foliata all occur in the oasis ecosystems, as do grasses of the Stipograstis species. Also growing in the western oases is bdellium (Commiphora wightii), a relative of myrrh that exudes an aromatic gum with some value as a trade good.
Bibliography
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