The pristine trees of a silk road poplar forest

The Taklimakan Desert is located in the largest inland basin in China-the Tarim Basin and it is the second largest desert in the world, which is surrounded by the Tianshan Mountains, the Kalakunlun Mountains, and the Kunlun Mountains.

The Tarim Basin is the world’s core area of these poplar trees which cover 352,200 ha, accounting for 90% of their total area in China and 54.29% of the global distribution.

Sand movements are frequent and intense throughout the year. The sandstorm days make up one third of a year, and maximum wind speed is up to 300m/s. The geography of the sand dunes in the nominated site is complicated and includes many dune types.

The poplar trees in the vicinity of the Tarim River are the oldest poplar trees in the world, emerging with the upheaval of the Qinghai-Tibet plateau. This kind of poplar tree has existed for more than 60 million years.

During the past 50 years, because of immoderate utilization of water resources by humans, water flows have been reduced in parts of the Tarim River, causing die-offs of poplar trees.

Fortunately, since 1990, steps have been taken to address these problems. Increased awareness of the need for environmental protection, the establishment of nature reserves and the implementation of enhanced water management, have enabled the poplar trees to thrive.

       The Populus Euphratica or Hero Tree…

Poplar trees are dioecious (self-propagating) plants that produce globular pollen that take root when they meet water. They also have heteromorphism (i.e. the character of the leaves changes with the age of the tree) and an extensive root network with strong ability to absorb water and withstand salt. The trees grow fast when there is enough water and the growth rate decelerates when the water resource is scanty.

Fossils of this kind of poplar tree have been discovered in the strata of the Tertiary Oligocene located at Kuqa Thousand-joss Cave and Dunhuang Blacksmith Grove. These fossils are about 3-6 million years old. These fossil trees have physiological characteristics that make them very hardy, enabling them to withstand both chilling winters and broiling summers, aridity, waterlogging and high saline-alkali concentrations.

There is an old saying that poplar trees can thrive for 1000 years, stand firmly for 1000 years after their death and fail to rot after falling down. 

The Tarim Basin is the world’s core area of these poplar trees which cover 352,200 ha, accounting for 90% of their total area in China and 54.29% of the global distribution. The largest natural poplar trees in the world occur in the Tarim River drainage area and large areas of undisturbed poplar forests have been preserved in this region.

Poplar trees date from the Tertiary and, therefore, have been regarded as living fossils of ancient species by botanists. They bear genes that endows them with the adaptation to withstand chilling winters and broiling summers, aridity and waterlogging, saline-alkali concentrations. Thus, these ancient rare trees, which possess great resilience, can be regarded as an invalauble natural gene pool.

Source: Unesco.org

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