Indigenous Plant Species from the Drylands of Iran, Distribution and Potential for Habitat Maintenance and Repair - Combating Desertification in Asia, Africa and the Middle East - page 344

N S

1000 - 2000 mm
precip.

m

subalp.

2500

Aragacanthic-

Quercus Vegetation

macranthera

Fagus
orientalis

Juniperus-
(Paliurus)

237 mm precip.

Tehran

Amygdalus-Pistacia
Artemisia-
Ephedra

100
mm

Artemisia

salt

Calligonum-
Haloseylon

Quercus castaneifolia-
Zelkova - Parrotia - Diospyros

Suaeda-
Salsola

Alnus - Pterocarya
Quercus castan. - Buseus

Caspian Sea

0 50 100 150 200 250 km

Fig. 17.2 Natural vegetation and elevation level on different aspects of Alborz mountain

Table 17.1 Most of the country is arid and hyper arid

Area Hyper arid Arid Semi arid Dry-sub humid Total

Worl d 7:5 12.1 17.7 9.9 47.2

Asia 6:5 14.7 16.3 8.3 45.8

Iran 35:5 29.2 20.1 4.9 89.7

Prolonged drought in this area and low available moisture in different parts of
Iran have produced different ecological zones. Iranian habitats support about 8,000
species of flowering plants (belonging to 167 families and 1,200 genera), of which
almost 1,700 are endemic (Eftekhari and Ramezani 2004 ).
The plant species growing on four Ecological Zones (Fig. 17.3 ) are subjected to
different physiographical and climatic conditions. These four ecological zones are:

• Hircanian

• Zagross

• Iran-O-Touranian

- Plains

- Mountain

• Khalij-O-Ommanian

Each of these four ecological zones supports a suite of plant species which are
adapted to the local conditions.