The Surprising Ecosystem Amidst The Al Hajar Mountains Of The Arabian Peninsula

A photo of a Zeravschan juniper growing near an oasis.

Have you ever wondered what lies hidden in the mountains of the Arabian Peninsula when most people picture only endless sand and dry rock? Many assume the whole area stays barren year after year. Yet, the Al Hajar mountains hold a different story. These peaks stretch across northern Oman and parts of the eastern United Arab Emirates, and they rise as the highest range in eastern Arabia, with some summits reaching over 3,000 meters (one meter is around 3.3 feet). The land there supports plants and animals that do not appear in the flat deserts below.

The climate in these mountains differs from the hot, dry plains that surround them. While lower areas stay warm most of the year, you would notice that temperatures quickly drop as you climb higher. At the top of peaks like Jebel Shams, averages sit around 15°C, and winter nights can even dip below freezing. Rain comes more often here than in the desert, though totals stay under 400 millimeters each year in many spots. Most precipitation falls between December and March, when the weather turns cool and wet. From April to September, occasional thunderstorms add short bursts of water. Mists and fog sometimes form on the slopes because of the height and the way air moves over the rocks. This extra moisture lets life take hold where it would otherwise struggle.

Vegetation changes step by step with the rise in elevation. At the base, shrubland covers the ground with tough, low plants that handle dry conditions. As you move upward though, the cover grows thicker. Between about 1,100 and 2,500 meters, woodlands appear with wild olive trees and fig trees mixed in. These trees find spots in valleys and on rocky outcrops where a bit more soil and water collect. Higher still, juniper trees take over in the cooler zones. One type, the Zeravschan juniper, stands out as a key species at the summits. In some places, the tree Ceratonia oreothauma grows, a species that, oddly enough, also lives far away in Somalia. Fruit trees such as pomegranates and apricots appear in cooler valleys where people have planted them, but wild growth includes other shrubs and grasses that fill gaps between the rocks.

An aerial view of a section of the Al Hajar mountains, revealing a seemingly barren landscape.

The mountains create pockets of richer soil in wadis and depressions. Water that falls on the peaks runs down through channels and sometimes stays in pools. These wet spots support plants that need steady moisture, including certain ferns and herbs that stay green longer than those on open slopes. Overall, the range holds around half of Oman’s plant species, with many found nowhere else. Endemic plants add to the count because the isolation of the peaks has let them develop apart from other areas over long periods. The mix draws from different regions, with links to flora in Iran and even parts of East Africa through ancient connections.

Animals make use of the same varied conditions. The Arabian tahr, a type of wild goat, lives on the rocky slopes and serves as one of the best-known residents. It stays in these mountains, and groups of these animals move across steep terrain to find food and avoid threats. Arabian gazelles also range through the foothills and lower slopes, where they graze on available plants. Wolves and striped hyenas hunt in the area, along with smaller mammals such as Sundevall’s jird. We can also find feral goats and donkeys, which share space with the wild species and sometimes compete for the same resources.

When it comes to birds, Egyptian vultures and lappet-faced vultures fly over the cliffs in search of food. At higher points like Jebel Shams, long-billed pipits breed in good numbers. Redstarts and scrub warblers move through the shrubs and trees during certain seasons. Reptiles show high numbers of species that live only in this range. Jayakar’s lizard blends into the rocks, while the blue-tailed lizard and Omani carpet viper occupy specific habitats. Geckos such as Pristurus gallagheri appear on the stone surfaces. In high-altitude pools fed by springs, fish like the Garra stone-sucker survive in clear water. The Arabian toad also lives near these wet zones and spends more time in water than many of its relatives.

A photo of mountains in the sparsely populated UAE Emirate of Fujairah.

People have lived in and around the Al Hajar mountains for centuries. Small agricultural settlements sit in bowl-shaped valleys where wadis cut through the rock. Terraces and channels called falaj carry water to fields for dates, limes, and other crops. These human activities have shaped parts of the vegetation, yet large sections of the range remain rugged and little changed. The mountains act as a barrier that catches rain and sends it downward, which helps recharge aquifers in the plains below, and without this effect, the surrounding desert would feel even drier.

As in most environments, water remains the key factor. Even though rain totals stay modest, the way the land catches and holds it matters. Rocky basins collect runoff, and springs emerge in certain valleys. These sources feed streams that flow for short distances before sinking back into the ground or evaporating. Animals gather near them during dry months, and plants with deep roots reach the moisture, while shallow-rooted ones depend on the seasonal pulses.

In the highest zones, the air feels thinner and cooler. Juniper stands form open woodlands rather than thick forests, with space between trees for grasses and herbs. This structure lets sunlight reach the ground and supports a mix of life. Lower down, the shrubland transitions into areas where acacia-like plants appear near the base. The full gradient from desert edge to summit creates many boundaries where species overlap or replace one another.

Records show that about 700 plant species live in the broader Omani section of the mountains. That count includes trees, shrubs, herbs, and grasses. Some appear only on a single peak or in one type of rock formation. Animals number in the dozens for mammals and reptiles, with hundreds for birds and insects when counts include seasonal visitors. The system stays balanced through these connections. Predators control herbivore numbers, while plants provide food and cover for everything else.

Efforts to list and protect endemic species continue. The Arabian tahr receives attention because its range has shrunk, and protecting its habitat will help other animals that share the slopes. Reptile surveys add new records and confirm how many kinds stay tied to specific elevations. Bird counts at breeding sites give data on how stable populations remain.

The Al Hajar mountains show that elevation can change conditions to support life in a part of the world known for heat and dryness. The climate provides just enough relief from desert extremes to let woodlands and shrublands develop. Vegetation follows the rise in height and moisture, while animals use the varied terrain for food, shelter, and movement. This setup has lasted through many dry cycles over the millennia and continues to function today.