Meighan desert has got a unique ecosystem. One of the most important aspects of its uniqueness is the Meighan wetland with a high quantity of biodiversity at its middle. The wetland is located 15 km North East of Arak, and 1670 meters higher than sea level. It is the most important home of migrant common cranes, Grus grus, in Iran, and also east Mediterranean Sea due to the problems that they face in other wetlands in Iran. There are more than 130 species of birds, such as duck family, flamingo, Larus minitus, gray crane, greylag goose, Ardea, etc. The area of the wetland changes from 10,000ha to 12,000ha depending on its water inputs. At present, 73 plant species are recognized, most of them are halophytes according to the salinity of the area. 10 of them are verified by International Protection Union, that two of them are endangered, eight of them are vulnerable. The most important specie is a local plant, called Qarah-Daq. Its most important property is sand stabilization.