Arabian Desert

The desert lies mostly in Saudi Arabia and covers most of the country. It extends into neighboring southern Iraq, southern Jordan, central Qatar, most of the Abu Dhabi emirate in the United Arab Emirates, western Oman, and northeastern Yemen. The ecoregion also includes most of the Sinai Peninsula in Egypt and the adjacent Negev desert in southern Israel. At an altitude of , rock landscapes yield to the Rub' al-Khali, a vast stretch of sand whose extreme southern point crosses the center of Yemen. The sand overlies gravel or gypsum plains and the dunes reach maximum heights of up to . The sands are predominantly silicates, composed of 80 to 90% quartz and the remainder feldspar, whose iron oxide-coated grains color the sands orange, purple, and red. A corridor of sandy terrain known as the Ad-Dahna desert connects the An-Nafud desert (65,000 km2 or 40,389 square miles) in the north of Saudi Arabia to the Rub' al-Khali in the south-east. The Tuwaiq escarpment is an arc that includes limestone cliffs, plateaus, and canyons. There are brackish salt flats, including the quicksands of Umm al Samim. ==Climate==

The Arabian Desert has a subtropical, hot desert climate, similar to the climate of the Sahara Desert (the world's largest hot desert). The Arabian Desert is actually an extension of the Sahara Desert over the Arabian peninsula. The climate is mainly dry. Most areas get around of rain per year. Unlike the Sahara Desert—more than half of which is hyperarid (having rainfall of less than per year)—the Arabian Desert has only a few hyperarid areas. These rare driest areas may get only 30 to of rain per year. The Arabian Desert's sunshine duration index is very high by global standards: between 2,900 hours (66.2% of daylight hours) and 3,600 hours (82.1% of daylight hours), but typically around 3,400 hours (77.6% of daylight hours). Thus clear-sky conditions with plenty of sunshine prevail over the region throughout the year, and cloudy periods are infrequent. Visibility at ground level is relatively low, despite the brightness of the sun and moon, because of dust and humidity. Temperatures remain high year round. In the summer, in low-lying areas, average high temperatures are generally over . In extremely low-lying areas, especially along the Persian Gulf (near sea level), summer temperatures can reach . Average low temperatures in summer are typically over and in the south can sometimes exceed . Record high temperatures above have been reached in many areas of the desert, partly because its overall elevation is relatively low. ==Flora and fauna==

The Arabian Desert ecoregion has about 900 species of plants. The Rub'al-Khali has very limited floristic diversity. There are only 37 plant species, 20 recorded in the main body of the sands and 17 around the outer margins. Of these 37 species, one or two are endemic. Vegetation is very diffuse but fairly evenly distributed, with some interruptions of near sterile dunes. and Asiatic lion used to live in the Arabian Desert. The ecoregion is home to 310 bird species. == People ==

The area is home to several different cultures, languages, and peoples, with Islam as the predominant faith. The major ethnic group in the region is the Arabs, whose primary language is Arabic. In the center of the desert lies Riyadh, the capital of Saudi Arabia, with more than 7 million inhabitants. Other large cities, such as Dubai, Abu Dhabi, or Kuwait City, lie on the coast of the Persian Gulf. == Natural resources ==

Natural resources available in the Arabian Desert include oil, natural gas, phosphates, and sulfur. == Conservation and threats ==

Threats to the ecoregion include overgrazing by livestock and feral camels and goats, wildlife poaching, and damage to vegetation by off-road driving. ==See also==