(ORDO NEWS) — The oldest alpine plant region on Earth, located in the Hengduan Mountains in southwestern China, is more than 30 million years old, scientists say. American and Chinese researchers say that the alpine flora of the Hengduan Mountains has continuously existed for much longer than any other alpine flora on Earth.
The plant diversity in the region today can be traced back to newly formed mountain ranges 30 million years ago and beyond, as evidenced by plant DNA analysis.
When the Indian tectonic plate crashed into Asia about 40 million years ago, the impact on biodiversity was like “jet fuel spillage” due to new weather conditions. According to scientists, the mountain’s alpine community includes special communities that are adapted to stressful environmental conditions, including past climate changes.
“Our historical reconstructions indicate that alpine flora appeared in the Hengduan Mountains region in the early Oligocene,” said Professor Xiang Yaowu of the Chinese Academy of Sciences. “This is much earlier than the alleged origin of other existing alpine floras.”
Scientists have focused their attention on plants growing above the tree line, called the alpine zone, in the Hengduan Mountains. This relatively small area has been found to be home to a third of all plant species in China. In the Hengduan Mountains, you can see coniferous forests, rushing glacial streams, rocky valleys and meadows teeming with wildflowers.
The team of scientists wanted to find out how the plants are distributed in the alpine regions of the Hengduan Mountains, the Himalayas and the Qinghai-Tibet Plateau, and how they got there. The researchers used DNA and fossilized samples to build family trees from 18 groups of flowering species and calculate how long ago their common ancestor lived.
The DNA of the various plant species found in this region can help determine how closely related plants are to each other and how they evolved. Scientists note that the formation of the rich in various plant species of the community was caused by “ancient city building” and is highly dependent on geology and climate.
Many of the plants first arose in the Hengduan mountains, but the collision of the Indian tectonic plate with Asia 40-50 million years ago slowly created new mountains, including the Himalayas. As a result, new habitats formed mountain slopes and valleys below and the region began to experience more intense monsoons. This may have happened because the mountains changed the prevailing winds, creating new weather patterns.
As the landscape grew more turbulent over time, now isolated plant populations diverged into distinct species, resulting in today’s biodiversity.
Finding out how species evolve and spread, and why some places are richer than others, is key to understanding and protecting the world around us, researchers say. Mountain ecosystems tend to be very sensitive to things like global warming because the organisms that live there depend on a narrow range of altitude and temperature.
“Understanding how historical environmental changes affected alpine plants 20 million years ago can help us predict how today’s climate change will affect their descendants,” said study author Dr. Rick Rea.
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