ORNAMENTAL PLANTS IN THEIR NATURAL HABITATS

Central Asia

Two great rivers, the Amu-Darya and Syr-Darya, the "Oxus" and the "Yaksart" or "Jaxartes" in the ancient tongues, flow through this region of where civilization arose. These rivers played important roles as trade routes from India via the Caspian and Black seas to Europe. The ancient provinces of Sogdiana (Tajikistan) and Bactrya (southern Turkmenistan) were known both in the East and the West.

Central Asia extends 1,300 km (800 miles) from north to south and 2,400 km (1,500 miles) from west to east. It consists of the Turanian Lowlands that gradually rise in the southeastern part to high mountain borders. Central Asia is very impressive in its dimensions and contrasts. It has the largest deserts in the FSU with the Karakum (about 390,000 sq km or 150,580 sq miles) in Turkmenistan and the Kyzylkum (about 300,000 sq km or 115,830 sq mi) in Uzbekistan and Kazakstan. It also has the highest mountains in the FSU: Tien Shan and Pamiro Alay. The name Pamiro Alay is used in Russian literature for the mountain system south of the Ferganskaya Valley (Ferganskaya Dolina) and the Tarum depression. The Pamiro Alay includes numerous high plateaus that range from 3,700-5,000 m (12,149-16,404 ft), and it is fitting that Pamir means in the Tajik language "roof of the world." These mountain systems have extraordinary peaks and ranges, with heights well exceeding European and American mountains. Thus the Pobeda peak in the Tien Shan reaches 7,443 m (24,420 ft) and the Kommunizma peak in the Pamiro Alay is 7,495 m (26,589 ft). The longest continental glacier in the world is the Fedchenko glacier, which at 80 km (49.7 mi) long, and 15 km (9.3 mi) wide, is situated in the Pamiro Alay. The climate of Central Asia is predominantly dry, but the presence of mountain ranges with various orientations causes marked environmental differences that influence the flora. Floristically, Central Asia belongs to the Irano-Turanian Region, the richest parts of which are the Armeno-Turanian and Turkestanian Provinces (Takhtajan, 1986). It is a transitional area between the montane vegetation to the west and related to the Caucasian flora, to the east related to Himalayan flora. Kamelin (1990) recognizes seven types of montane terrain within this region: extra arid hill country, arid hill country, arid and semi-arid submontane country, subarid mountains, humid mountains, high mountains, and high mountain plateaus.

Central Asia has so far yielded a relatively small number of ornamental species to world gardening, although it is reported to have 8,000 species of vascular plants (Kamelin, 1990). There are more than 60 endemic genera and numerous endemic species that include a large number of potentially ornamental herbs and woody plants, mostly shrubs. Although these attractive plants can be found in diverse vegetation types and habitats, the majority grow in the mountains. The foothills and lower montane zones support various types of desert vegetation and here most species grow in spring as ephemerals (annuals) or ephemeroids (perennials). Deciduous shrubby thickets or sparse forests characterize mountain slopes and consist of juniper (Juniperus) and various steppe formations, together with tall plants of the carrot family (Apiaceae). Deciduous forests include maple (Acer), apple (Malus), common walnut (Juglans regia) and form isolated stands. Coniferous forests, dominated by Schrenk's spruce Picea schrenkiana and fir Abies semenovii, are even less common. The high-altitude vegetation consists of meadows, steppes and cushion subshrub communities. As a whole, the flora of Central Asia is of great interest as a potential source of new woody and herbaceous plants.