Desert re-forestation work in Iran
Begun as soon as 1928, the work of desert greening that has already taken place in Iran is enormous and monumental, and is probably the largest application of good desert repair work in the world and is the largest-scaled effort in the history of the world, with 2 mln hectares of desert project area under rehabilitation.

Half of the 3 mln trees will be planted in a 100 km stretch between the towns of Anau and Baharly in the country’s south, while the other half is to be planted in by local authorities across Turkmenistan’s five regions. The trees will be a mix of unspecified deciduous, coniferous and fruit trees, as well as grapevine, all of which are to be provided with sufficient irrigation, the report said.

Desertification has played a significant role in human history, contributing to the collapse of several large empires, such as Carthage, Greece, and the Roman Empire, as well as causing displacement of local populations.

The world’s great deserts have been formed by natural processes interacting over long intervals of time. During most of these times, deserts have grown and shrunk independent of human activities. Paleodeserts are large sand seas now inactive because they are stabilized by vegetation, some extending beyond the present margins of core deserts, such as the Sahara, the largest hot desert.

Drylands occupy approximately 40-41% of Earth’s land area and are home to more than 2 bln people. It has been estimated that some 10-20% of drylands are already degraded, the total area affected by desertification being between 6 and 12 mln km², that about 1-6% of the inhabitants of drylands live in desertified areas, and that a billion people are under threat from further desertification.

Desert greening is more or less a function of water availability. If sufficient water for irrigation is at hand any hot, cold, sandy or rocky desert can be greened. Water can be made available through saving, reuse, rainwater harvesting, desalination, or direct use of seawater for salt-loving plants.

The use of water is, however, not always without problems. Desert greening by the Helmand and Arghandab Valley Authority irrigation scheme in Afghanistan significantly reduced the water flowing from the Helmand River into Lake Hamun and this, together with drought, was cited as a key reason for the severe damage to the ecology of Lake Hamun, much of which has degenerated since 1999 from a wetland of international importance into salt flats.