Only about 11% of Iran is arable land, 8% is forest, 47% is natural pastures, and 34% is infertile land, including desert.
More than half of Iran is covered with mountains, with four ranges most prominent. The smaller, volcanic Sabalan and Talesh Ranges in the northwestern Azeri provinces provide fertile pastures for nomads. Nearby the majestic Alborz Mountains skirt the Caspian Sea from the border of Azerbaijan as far as Turkmenistan, and are home to ski fields and the snow-capped Mt Damavand (5671m), the Middle East's tallest mountain. The northern slopes of the Alborz Mountains are densely forested to about 2500m and form the largest area of vegetation in the country. The forests will look familiar to Europeans (oak, ash, pine, poplar, willow, walnut, maple and elm), and the loveliest pockets are around Masuleh, in the Golestan National Park east of Minudasht, and, more accessibly, at Nahar Khoran, just south of Gorgan. There are several peaks reaching more than 4000m, though heights fall to an average of 1500m in the south.
All these mountains exist because Iran sits at the junction of three major tectonic plates - the Arabian, Eurasian and Indian - making the country highly susceptible to earthquakes.
East of the Zagros Mountains is the central plateau and its two vast deserts, the Dasht-e Kavir (more than 200,000 sq km) in the north and the Dasht-e Lut (more than 166,000 sq km) in the southeast, accounting for almost 25% of the country. The deserts include occasional salt lakes and are dotted with luxuriant oases - a welcome sight for travellers down the ages.
National Parks & Reserves
National parks, and the wildlife they are designed to protect, are luxuries most Iranians don't have the time, money or education to be concerned with. As a result, most national parks are terribly underfunded and understaffed, and the most accessible zones tend to be rubbish-strewn picnic sites. Unauthorised hunting is an ongoing problem, as is illegal cultivation. Attitudes are changing in cities such as Tehran and Shiraz but it could be decades before Iran's nature reserves have the status of their Western counterparts.
Unlike many ancient civilisations, such as those in Egypt and Mesopotamia, Persian settlements did not develop around major rivers. The longest and sole navigable river is the Karon (890km) in the southwest. Rather, settled areas are almost entirely confined to the foothills of mountains, where natural springs and melting snow provide sufficient water, with melted snow often channelled through ingenious underground canals called qanats.
For at least 2000 years, Iranians have been digging qanats (underground water channels) to irrigate crops and supply drinking water. Iran is thought to have more than 50,000 qanats. While modern irrigation projects now take priority, qanats and other traditional methods of supplying water are still very important.
Chronic air pollution is the environmental problem you are most likely to notice while travelling in Iran. Tehran sets the standard but growing industry and car ownership have made poisonous air a problem across the country. Iran's pollution problem is worse for having been ignored until it reached crisis point.
Unfortunately, centuries of tree felling, grazing herds of sheep and goats, culti-vation, as well as modern pollution and urbanization have had a serious impact on the environment. The vast stretches of primary forest have been seriously depleted and a large part of the Zagros, now covered in grasses and bushes, is suitable for grazing but no longer supports trees. In the past 25 years or so, the Iran-Iraq war, and atmospheric and maritime pollution brought about by the burning of the Kuwaiti oil fields during the Gulf War, have also had an effect on the Iranian environment. The Shadegan marshes and the Khor al-Amaya and Khor Musa tidal mudflats, for example, have been contaminated, probably by Iraqi chemical weapons. The draining of marshland and its conversion into arable land has led to the disappearance of numerous species of birds, frogs and insects. Twenty years ago, more than 12 million birds migrated regularly through the Iranian marshes; today there are just over one million. Although hunting and pollution have contributed to this decline, the main factor behind it is the loss of the birds' natural habitat. This draining of the marshes is sometimes linked to irrigation projects: the Hamun-e Saberi Lake in Sistan was practically dry during the winter of 1976 because of the construction of a dam on the Hirmand in Afghanistan.