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 352

3 Re-vegetation Based on Locally Adapted Species

Large-scale re-vegetation has been a feature of Iran's efforts to rehabilitate degraded
rangelands (See Chap. 18 ) .

3.1 Desertification and Its Control by Plant-Based Methods

Wind erosion and its destructive effects on natural resources and the environment
has been a serious problem in Iran from olden times. Basically, wind erosion
control involves land salvage and re-vegetation in areas that are subjected to it
because of denudation. Although there had been efforts to control it, it was not
until 1965 that an organized attempt for checking the phenomenon was launched by
establishment of a station in an area of 100 ha south of Sabzevar, Khorasan province
(See Chap. 18 ) .
The objectives were protection of the environment; stabilization of shifting
sands and dunes; preservation of farming lands, conservation of water resources
including the Ghanat system, and water supply installations; protection of roads
and water distribution networks; and reclamation of settlements and prevention of
the inhabitants' emigration. The results of more than 25 years of sand dune fixation
activities in the country are plantation of 1 Mha with seedlings and 2 Mha of seeding
which has protected or rehabilitated more than 4 Mha.

3.1.1 What Techniques Work?

Doubtless the most rational and efficient way to stabilize the shifting sands,
rehabilitation of plant cover and reclamation of ecological conditions. But since the
soil is not stable, sometimes it is necessary first to stabilize it temporarily against
movement with windbreaks or palisades (see Chap. 3 ) (Fig. 17.5 ).
Barriers comprised of shrubs, woven canes, and tree branches are placed over
dunes in rows or cross-lined patterns help to protect the surface (Fig. 17.6 ).
Mulching the soil surface with petro-chemical derivatives is another efficient way
of temporary stabilization of dunes and creating opportunity for seeds and seedlings
to grow and strike root. Mulch is a substance obtained from petroleum during
refining. Mulches, after extraction of aromatics and adding chemical additives as
per formulation (which varies according to areas), is carried in tankers to the area.
Mulches are heated there and sprayed over the soil by special devices (Fig. 17.7 ).
But for permanent stabilization of dunes, plant cover must be fully restored.
This may be carried out through seeding, plantation of seedlings, and cuttings.
The required seeds may be partly obtained from other planted areas and partly
from natural forests of deserts. Locally adapted ecotypes provide the best seed
source. The required seedlings are grown in nurseries either in beds or in plastic