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 Current Location: Populus euphratica>>Detailed information

1. Morphological characteristics
Populus euphratica is a deciduous tree varied from 10m to 20 m in height. It was characterized with obvious main trunks, open crown; gray yellow to brown thick bark, with deep longitudinal strips; gray-green or yellow-brown smooth branches. Leaf shape is variable: strip with pointed apex and sparse wavy sawtooth on the sprouting saplings and long branches of young tree or base on adult tree; while lanceolate, ovoid or broad ovate (the leaves on flowering branches are broad ovate) leaf with slightly serrated or deep sawtooth on adult tree. The male catkin inflorescences contain 25~28 flowers in average, and the female contains 20~30 flowers; the ovary is long ovoid, composed of 3 carpels, with short tomentose or glabrous; the stigma is 2 to 3 lobed. The capsule is oblong or ovoid. The seeds are small, yellowish-brown or reddish-brown, oval or olive-shaped, 1-1.2 mm long, 0.5-0.7 mm in the middle, white short hairs on the seeds, and many white filamentous hairs at the base of the seeds. Flowering during April, fruiting during from July to August. From the perspective of morphological characteristics, the leaf shapes of Populus euphratica between young and adult trees or upper and lower of individual crown are significantly different with other section of populus. So, it is called "diversifolia poplar". The size of Populus euphratica genome is approximately 511.3Mb (2n=38).
2. Growth characteristics

Populus euphratica grows slowly in 1-5 years, with tree height of about 1-1.5 m, and the ratio of tree height to root system is 1:2.After 10 years of age, the tree growth increased rapidly, and the peak of tree height growth appeared at 10 - 12 years of age.From 25 to 30 years of age, the growth of tree height gradually slowed down, while the growth of DBH continued to increase.When Populus euphratica is 60 to 65 years old and enters the mature stage, the trunks of the budding Populus euphratica are susceptible to heart rot from 30 to 40 years old under the condition of poor site conditions.The development history of Populus euphratica and Populus pruinosa was divided into the following stages:

(1) juvenile stage: from seed germination to the young plant of 3 to 4 years old.This stage is characterized by: the growth of the aboveground part is slow, and the growth of the underground root system is fast, especially 1 - 2 years before.In the first year, the aboveground part grows about 6 - 8cm, and the root system of the underground part grows 15 - 20cm.In the second year and the third year, the height of the aboveground part is 20 -30cm and 30 - 40cm respectively.The root length of underground part is 40 - 60cm and 60 - 80cm respectively.The leaf shape is bar.

(2) Dry wood stage: 4 - 14 years old, which is the high growth stage of Populus euphratica.Generally up to 4 - 7m, diameter at breast 6 - 10cm.The crown of the tree is narrowly oval, and the top of the tree is pinnacle.In this period, under the condition of good soil moisture and light saline-alkali, most of the leaves were lanceolate, with only a few sparse and small serrations at the edge of the crown occasionally appearing.However, as habitat conditions deteriorated, serrated leaves appeared earlier and increased correspondingly.

(3) Middle age stage: 15 - 35 years old, which is the dry growth stage of Populus euphratica.Under good soil moisture condition, the tree is 10 - 14m high and 15 - 30cm at breast diameter.The crown of the tree is broad oval, and the top is pinnacle shaped.Leaves ovate and broadly ovate in the middle and broadly lanceolate on the top twigs.

(4) Mature stage: 35 - 60 years old, tree height 14 - 18m, DBH 30 - 50cm.Bark rough, have very thick cork layer, longitudinal crack deep, part into strip peeling.The crown is oval, domed or obtuse.Lower trunk branches die, especially under the environment of large forest canopy closure, natural pruning death phenomenon is strong, leaves are wide oval.

(5) ripe stage: 60 - 80 years old, such as in good soil and water conditions, can last to 100 years.The height of the tree can reach 20m, the diameter at breast height is 50 - 70cm, and the maximum can reach more than 100cm.Bark is very rough, thick up to 10cm above, deep longitudinal crack, flaking.There are few branchlets (or twigs) on the trunk, and the crown is sparsely broken and not very symmetrical.Heartwood often dry rot even hollow (especially in the case of poor site conditions), slow growth or even close to dry stop.

(6) Senescence (or death) stage: the tree crown withered or all dead.The trunk stiffened and stood firm.Under good natural conditions, the natural life of Populus euphratica can reach more than 150 years, the height of the tree can exceed 25m, and the diameter at breast height can reach 130cm.The longevity, growth and development of Populus euphratica mainly depend on the quality of habitat conditions, among which the changes of soil salt and water content play a leading role.If in good soil conditions (mainly the soil salt content is low, sufficient moisture), they can pass through all stages of development smoothly, and grow into good wood.In different developmental stages, their ability to resist environmental stress is different.In terms of drought resistance, the dry wood stage is not as good as the middle age stage, where the soil dies first when it becomes extremely dry, while the mature plants continue to live for a long time.

3. Phenological stage of flower and fruit
Populus euphratica is an anemophilous plant with flowers followed by leaves in the floral phenophase.The period from flowering to seed maturity of Populus euphratica lasted 150 days, the duration of flowering period was the shortest, and the duration of fruit maturity was the longest, up to 141 days.In Xinjiang, the flower bud differentiation of Populus euphratica begins in late May and matures in early March of the next year. The flower bud initiation enters the flowering period in late March and the flowering period ends in mid-April.Capsule matures from July to August.
4. Root characteristics
Under the condition of better soil moisture, the taproots of Populus euphratica were not developed, only 50 - 80cm long, while the lateral roots were developed and expanded horizontally, up to more than ten meters in length. The lateral roots at all levels were concentrated in the topsoil layer of 30 - 50cm, forming a strong root network.The horizontal root system of Populus euphratica has a strong ability of root and tiller. Irrigation, trenching and root breaking often promote a large number of root and tiller seedlings on the horizontal root, which is one of the ways to promote the recovery and development of Populus euphratica.In extremely arid soil conditions, the taproots of Populus euphratica can reach deep.In the old passage of Tarim River, when the groundwater level reached 13.5m, the root system of Populus euphratica could still be seen.The developed root system is an important guarantee for Populus euphratica to adapt to various site conditions.
5. Natural propagation method Seed propagation

Populus euphratica seeds mature from July to September when the climate is hot and rivers flood.Large quantities of crested seeds are blown to the floodplains along rivers, the shallows of flooded lakes, the wet bottoms of dry gullies and the waterlines of slopes on newly built water channels in agricultural areas.These seeds germinate rapidly and grow together with other accompanying plants to form strip and sheet forest communities.

Tiller propagation: Under arid desert conditions, the seed propagation of Populus euphratica is limited, but the root and tiller propagation is common.Under the condition of better soil moisture and less salt and alkali, the adventitious buds can be produced on the developed horizontal root system for root tillering propagation, which is the main way of natural propagation of Populus euphratica.Within 20 to 30 meters of a Populus euphratica mother tree, dozens or even more progeny can be seen from roots and tillers, forming clumps of young forests.Over the years, these clumpy young forests can grow into dense secondary forests.In many places, it forms the special forest features of Populus euphratica forest.