Saxaul – the main in the desert
06.04.2020 | 11:38 |
The flora of Turkmenistan is rich and diverse, it has more than 2500 species of flora, 700 of which grow in the desert. Saxaul (lat. Halóxylon) is the main tree of the Karakum desert and the sands of Central Asia.
Two types of saxaul coexist in the desert - white and black. They are very similar, but the experienced eye can already distinguish them from afar: the light groves of the white saxaul are more transparent, and it is smaller, thinner, more graceful than black, and the bark on the branches and thick trunk is whitish-ash. In order not to be mistaken, you need to compare the young branches. Saxaul shoot is composed of green segments - similar to horsetail, only juicy. And at the base of the joint, a pair of barely visible bristles remain from the leaves of the white saxaul, and a pair of tubercles in the black one.
Saxaul parted with leaves on an evolutionary path for the sake of economy: the smaller the surface of the plant, the less water it evaporates. And for photosynthesis, having lost leaves, it adapted green shoots.
Saxaul, especially black, has a powerful root system that draws groundwater, even if it is very deep. The plant does not suffer from thirst, but its shoots are so juicy that if you press with your fingers, moisture will spray (salty!). Such juicy forms spend water on evaporation extremely sparingly. Therefore, saxaul has a double guarantee in life: practically non-exhausting groundwater and tough savings during evaporation. By the way, it is also necessary because water can be salty, and its excessive consumption would lead to the accumulation of salts and subsequent poisoning of the plant.
There is something martyred in the appearance of saxaul: the trunks are twisted, turned, some flowing in its beautiful but suffering plastic; gray, as if in ashes, twigs and branches hanging gray hairs. It seems that the tree is not less than a thousand years old and geological antiquity blows from it. Meanwhile, it is no more than sixty! Such an age is the limit for black saxaul.
The tree, of course, cannot be called deciduous, but with the onset of cold weather it is exposed. Fallen juicy twigs contribute a lot of salt to the soil, which causes a gradual change of the few grasses growing near the tree, since more salt-tolerant ones get an advantage.
In March, the saxaul trees stand as if they were showered with millet - its yellow flowers are very small. They are pollinated by the wind. Large bubbles grow on the anthers - this increases their windage and thereby enhances the vibration of the stamens in the wind. A gusty strong wind vigorously shakes pollen; part of it settles on the near and distant flowers. Only in the fall the fruits ripen. And then it seems that saxaul bloomed a second time: on the missing cup grow elegant translucent wings, yellowish or pink, which make them look like flowers.
The wind picks up the ripe fruits and carries them and rolls along the sand, but not very far, as a rule, no further than a dozen meters. Sown, they sprout quickly: their embryo, rolled up by a ringlet, is straightened, and on the second or third day the root is thrust into the sand. Such swiftness is justified: if it didn’t rush, it would be covered with sand. The thin green tail of the saxaul seedling grows very slowly, but the root extends a meter by the fall - the plant is in a hurry to quickly reach the moist horizon of the soil. Only in this is its salvation and guarantee of victory in the competition with scorching heat. All life in the desert is sharp - a competition not for life, but for death. With sand, with the wind, with the sun. With humans.
In the desert, a person also needs fuel, as elsewhere: in winter - for heating and constantly - for cooking. So saxaul trees go for firewood. Saxaul fuel, one might say, is ideal: it burns almost without smoke, does not crack, does not shoot sparks, does not smoke, lights up even raw from the first match, and approaches calorific value of the coal.
Now artificial plantations of saxaul are in practice; seedlings grown under favorable conditions give a larger seed yield than natural thickets. In spring, sheep and camels readily eat black saxaul overgrowth, whose shoots quickly resume, in winter it is also an additional source of food for farm animals in distant pastures. Black saxaul is of interest not only as a forest-forming species, but also as a fodder plant - it strengthens sands and improves pastures. Where protective stripes from black saxaul are created, waste salt marshes are healed, and the stocks of fodder mass of desert pastures are increased. This plant forms the soil in desert lands - saturates it with organic matter and regulates the level of groundwater. In addition, saxaul thickets protect settlements from dust storms.
