Chemistry Reference
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in spite of its succulence characteristic and its ability to store water in different plant
parts (Fig. 4). This species has been considered as a desert species suspected as
halophyte. Its life form was considered as Sub-Fruticose Chamaephytes, erect fruit
shoot at base [38]. It grows in various habitats, including disturbed areas and saline soils,
in deserts, plains, coastline, and other places. It is a fleshy annual plant, producing
several erect, ribbed stems 35 to 45 centimeters in maximum height. Although these
plants are considered as xerophytes, they might have also well adapted to saline
environments, since they are living in soils of high salinity levels [4].
Figure 3.
Branches of
Tetraena qatarense with
the fleshy leaves and woody stems.
b.
Accelerated water absorption by water spenders: some plants can improve water
uptake and content under drought by producing extensive roots or intensive fibrous
root system to increase the active root surface area.
Helianthemum lipii
is a good example
of a plant species having roots growing in the deeper soil layers toward the water table
(Fig. 5). Also, some plants have high root / top ratio such as
Cyperus conglomeratus
(Fig.
2) which helps to cope with drought as mentioned before [15, 19, 26].
(C) Drought tolerance
Plants can tolerate drought (water stress) by two main mechanisms: (a) Dehydration
avoidance. (b) Dehydration tolerance
.
Plants living in the State of Qatar are resistant to
drought not only because of the morphological characteristics as avoidance mechanism, but
