☰ Contents · Geography

Plants of Central Asia and desert plants

Lessons 26–27 · 2 lessons · P. Gulomov, H. Vahobov, P. Baratov, M. Mamatqulov. Geography (Physical Geography of Central Asia; Physical Geography of Uzbekistan), Grade 7. Revised and expanded 5th edition. “O‘qituvchi” Publishing House, Tashkent, 2017
27

Desert plants

Textbook: p. 61
GoalKnow the kinds of desert plants and how they are adapted to desert conditions.
New words
saxaul · saksovulephemerals · efemerlarsalt marsh (solonchak) · sho‘rxoktugai (river-valley woodland) · to‘qay
Explanation

Desert plants differ in sandy, stony and clayey deserts. Sandy deserts have white saxaul (reaching 6–7 m), juzgun (Calligonum), sand acacia, wormwood and saltworts; in spring tulips, boychechak (an early spring flower) and sedges also bloom. Stony deserts have sparse vegetation such as wormwood, tuyatovon and kermek. Salt marshes have saltworts, black-leaved saltwort, sarisazan and black saxaul. On loess in the piedmont plains lie ephemeral deserts: ephemerals sprout quickly on the wet days of spring, bloom, set seed and wither before the summer heat begins. Desert plants are adapted to dryness: roots are long and leaves small, needle-like or absent, and some use salty water as well. Along rivers and lakes there are tugai, where turanga poplar, willow, oleaster, reed and tamarisk grow.

Worked examples
Saxaul roots go very deep, sometimes 10 m or more, and its leaves are reduced to tiny scales, so it loses little water.
Tulips bloom in April, set seed and wither in late May, and spend summer as a bulb underground.
Class activity

“Adaptation cards”: cards show a plant (saxaul, tulip, reed) and an adaptation (long root, small leaves, quick flowering); match them and explain. We work from pictures; plants in the desert are not picked.

Practice
1
Which tree is the most widespread in sandy deserts?
2
What are ephemerals and when do they develop?
3
If a saxaul root reaches 12 m deep, how many metres is half of that depth?
4
Why are desert plant leaves small or needle-like? Explain the adaptation.