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Greening Tehran to Help Improve Air Quality

Greening Tehran to Help Improve Air QualityGreening Tehran to Help Improve Air Quality

Tehran in the not too recent past was called ‘Chenarestan’ or the ‘land of plane (platanus) trees’. The tree’s flat and large leaves (each tree has 10,000 to 15,000 leaves) purify the air. Also the trees’ deep roots can save soil by holding moisture and prevention of erosion.

The tree absorbs surface waters and then transfers the waters to underground aquifers, said Esmaeil Kahrom, an advisor to Masoumeh Ebtekar, the head of the Department of Environment (DoE). “Lawns are only decorative as grass doesn’t have the ability to improve the air quality and requires lots of water to thrive,” he maintained.

Grass is not suitable for lawns in cities with arid and semi-arid climate, as plants with shallow roots need plenty of water to survive.

With consecutive years of drought in the country, Ali Mohammad Mokhtari, general director of Tehran’s Parks and Green Spaces Organization blamed “planting of grass lawns for wastage of water resources” in the capital. To conserve water resources, the organization has decided to replace all the lawns across the city with better green alternatives,” he said, reports khabaronline.

In addition to plane trees, hackberry and willow trees are consistent with Tehran climate. Also some fruits plants including mulberry can be placed in the category of alternative vegetations. “Although fruit trees aren’t the top priority, as they (fruit) are not consumable due to the city’s air pollution. Also the city’s streets can become messy with fruits falling on the ground; this is another problem of planting such trees,” Mokhtari added.

 Varied Climate

Tehran has three different climates in the northern, central and southern parts. The suitable vegetation for each part is different. For the central part a combination of both northern and southern vegetation is suitable.

The northern and north-eastern natural vegetation mostly include willow, walnut, plane, ash and populous which commonly grow on the sides of water streams and in the valleys.

Many plants in Tehran, such as magnolia, chimonanthus, bay tree, trumpet vine, wisteria and verbena are not native to Iran but are commonly planted in the city due to their acclimation to the climate.

“At present, using plants that need less water,  especially species which are resistant and consistent with Tehran’s climate, is on the agenda,” Mokhtari said.

 Restoration

Further, planting halophyte vegetation (salt-tolerant plants) in the zones around the city, where the amount of salt in soil is higher than normal, is also on the agenda, he added.

Meanwhile, nearly 500-1000 plane trees are being planted along the Vali-e-Asr St.  Old plane trees with strong roots are also being shifted and replanted along the street. The measure has been taken for restoration of the street trees. Currently several trees have dried up due to air pollution and poor maintenance.

Vali-e-Asr is the longest tree-lined avenue in the Middle East and some of the trees are more than 100 years old.

Financialtribune.com