A critically endangered plant that is rarer than the giant panda, "returns" from the tiankeng after a hundred years of disappearance

  Science and Technology Daily reporter Zhao Hanbin

  Many of the beautiful things in the world are once missed and cannot be found again, but some can only rely on the claws of the snow and mud, leaving a trace of clues. After decades or hundreds of years, they may meet again, such as the big flower stone. Butterflies and bamboo produce goat milk.

  Dahuashi butterfly and bamboo goat milk are both "extremely endangered" plants, which are of great research value and economic value.

  One hundred years ago, foreign botanists collected specimens of large flower stone butterfly and bamboo goat milk in Yunnan, my country, and made some simple records. Since then, these two plants have quietly disappeared between mountains and rivers.

Things change stars and move for several autumns, and when people are looking for their traces, changes in habitats and human interference, which are originally rare, become even more rare.

  A few days ago, the reporter learned from the Kunming Institute of Botany, Chinese Academy of Sciences, that the team of collectors from the Southwest China Wildlife Germplasm Bank (hereinafter referred to as the "germplasm bank") has "exhausted effort" from these two plant models. The specimens were collected around a Tiankeng in Mengzi, Yunnan, where they were found again, and protection measures were implemented.

  Tiankeng provides a refuge for the growth and development of animals and plants

  Tiankeng is a large-scale pit-like negative landform formed by the continuous erosion of the limestone strata in the karst area through the underground river and finally the surface collapse.

The surrounding rock walls are steep, and the unique geological landforms form a microclimate different from the surrounding area and a unique habitat suitable for biological survival.

  In the past, people have always regarded tiankeng as a special case of karst funnel. In 2001, Chinese scholars formally proposed to name this karst landform "tiankeng".

  The tiankeng is tens to hundreds of meters deep and has a huge volume, which is often difficult for humans to reach, avoiding human interference.

The bottom of the tiankeng is often connected with underground rivers, or there have been underground rivers that have migrated.

  "Research on the tiankeng plant community at home and abroad, as well as the discovery of many new records and new species in tiankeng in recent years, all show that the relatively independent ecosystem formed inside the tiankeng provides a refuge for the growth and development of some animals and plants. As far as plants are concerned, they are more likely to differentiate into biological groups that are different from the surrounding areas. They have the characteristics of rich plant species, special vegetation types, and abnormal flora composition. Therefore, the study of biological diversity has important scientific value." Dr. Zhang Ting, head of the seed collection team of the Quality Resource Bank, said.

  In order to effectively preserve the germplasm resources of species in this special habitat, in early 2021, the germplasm resources bank of Kunming Institute of Botany, Chinese Academy of Sciences, with the support of the Alpine Science Promotion Center, cooperated with the Honghe Prefecture Forestry and Grassland Bureau to investigate the surrounding areas of Mengzi City. Preliminary investigations were carried out on several tiankengs in the city, and on June 17, 2021, with the assistance of drone detection and a professional rock climbing team, a rappelling method was applied to a site with a diameter of more than 100 meters in Mengzi City, Honghe Prefecture. , A large tiankeng with a depth of about 60-100 meters has carried out the investigation and collection of germplasm resources.

  “This is the first time that social forces have participated in the rescue collection of germplasm resources in the 14 years since the germplasm resource bank has been in operation.” Dr. Zhang Ting said, and this tiankeng investigation has yielded fruitful results in the collection of germplasm resources.

  Big flower and stone butterfly found on Tiankeng cliff

  The large flower stone butterfly plant is slender and has large flowers. It is beautiful and beautiful. It is a plant of the genus Gesneriaceae. It is born in limestone walls or stone crevices at an altitude of 1200-2100 meters. It is named for its slender plants with large flowers.

  In 1895, British botanist William B. Hensley described it as a new species of the genus Stone butterfly based on a specimen collected by William Hancock from the Mengzi region of Yunnan Province. The type specimens are now in the Kew Gardens of the Royal Botanic Gardens. The herbarium has not been found since then.

According to media reports, my country's Yunnan Wenshan, Guangxi Guilin, Guangdong Shenzhen and other places have discovered and planted the large flower stone butterfly, but after careful identification, it is not the species.

  According to the evaluation of the International Plant Conservation Union (IUCN) standard, the endangered level of the big flower stone butterfly is "critically endangered" (CR), and the number of individuals found at that time did not exceed 300, and one of the populations along the road was affected by human activities Larger, survival is greatly threatened.

  The morphological characteristics of the Dahuashi butterfly contained in Flora of China are: "small perennial herb. There are many leaves, all basal. The outer leaves are 14.5 cm long, with long stalks, and the inner leaves are small, short-stalked or nearly sessile; When the leaves are dry, they are papery...Inflorescence 4-10, each with 1-3 flowers; peduncle length 2.5-5 cm; bracts 2, small, linear. Origin distribution: Yunnan Mengzi. Born on mountain limestone , About 2100 meters above sea level."

  For a long time, it has been difficult to determine the true face of the big flower and stone butterfly.

The National Specimen Platform can only find two specimens of the Big Flower and Stone Butterfly, one of which was exchanged by Mr. Chen Huanyong from the Kew Herbarium of the Royal Botanic Garden in the United Kingdom. The specimens are incomplete, only a few leaves and fallen flowers; One specimen is actually another species of the genus Stone butterfly.

  Han Mengqi, a doctoral student at the Institute of Botany, Chinese Academy of Sciences, specializes in the study of the genus Stone butterfly.

In 2020, he found a population of large flower and stone butterflies near Mengzi, Yunnan.

  "Because we are doing germplasm resource protection, Dr. Han Mengqi told us the situation of this distribution point. In order to collect the seeds of the big flower stone butterfly, our team went back and forth four times to observe its flowering and fruiting period." Zhang Ting said, The large flower stone butterfly has a small distribution area in the wild, and its seed setting rate is very low, which may be one of the reasons why it is endangered.

  124 years after Hancock published this species, the collection team of the Germplasm Bank was finally lucky enough to collect the first batch of seeds of the large flower stone butterfly at the place where the type specimen was discovered.

  On the cliff of this tiankeng, Zhang Ting and his teammates can discover a new colony of the "Hundred Years Encounter" Big Flower and Stone Butterfly, which is not easy.

"The environment of the wild population of Big Flower and Stone Butterfly is very special. It is not only on the cliff wall, but also in the deep recessed rock crevice, which is equivalent to maintaining another smaller microenvironment; it requires relatively high humidity. The temperature and humidity must be stable." Zhang Ting said that when they descended from the cliff, they looked for it from multiple angles and searched the tiankeng, only to find this population at last.

Without affecting the population in the wild, they brought a small part of the living body, and then bred.

With the live body and the seeds harvested last year, the big flower and stone butterfly is expected to bid farewell to the extinct or endangered situation.

  Zhang Ting introduced that in the genus Gesneriaceae, the flower is the largest, and the flower color is gorgeous. Many new varieties have been selected and bred from abroad with it, which has extremely high development value.

At present, tiny potted flowers are more popular on the market, and some institutions specializing in the research and development of new flower varieties have begun to develop and utilize this rare resource.

 Goat milk from bamboo may become a new fruit

  Fortunately, in the surrounding area of ​​Tiankeng, Zhang Ting and his teammates also obtained the mature seeds of another "Hundred Years Encounter" plant Zhusheng Goat Milk.

  The type specimen of bamboo-born goat milk was collected by the Austrian botanist Han Madi on March 8, 1915 on the way to Manchu in Mengzi, Yunnan. It is now in the Herbarium of the University of Vienna, Austria, and no specimens of this species have been recorded since then. , Has been "disappeared" for 106 years.

The number of bamboo goat milk individuals found again is less than 20, and most of the plants grow around the village, which is greatly affected by man-made, and its endangered level in IUCN is also "critically endangered" (CR).

  "Under the background of increasing global ecological destruction and rapid loss of biodiversity, our country is also under pressure. As seed collectors, we can say that we are racing against time." Zhang Ting said.

Goat milk with bamboo is a plant of the genus Elaeagnus in the family Elaeagnus.

It entered Zhang Ting's list of targets because of the lack of research and poor records.

  The record of "The Flora of China" only comes from Han Madi's simple description: it was produced in southeastern Yunnan; it was born at an altitude of 1,800 meters.

Type specimens were collected from Mengzi, Yunnan.

  "But in fact, there is no type specimen or even a line drawing of it in China. Whether you have consulted various records and monographs, everyone has not found it, and you may think it has disappeared." Zhang Ting said, but He still didn't give up and looked up the information over and over again, but to locate a species in a huge area was tantamount to finding a needle in a haystack.

  Zhang Ting even inquired about Han Madi’s scientific expedition diary, but the diary did not mention this species. He analyzed the general trajectory and time node of Han Madi’s walking, and searched for local people to find the remains of the ancient road.

"The luck was pretty good. I finally found'her' during the flowering period." Zhang Ting said, but this time I went and saw that the first two trees found on the farmland had been cut down.

  The amount of bamboo goat milk seeds is relatively small and the distribution is very narrow. They have collected a standard amount of at least 2500 grains. Zhang Ting and the others will need to go back and forth several times in the next two years.

  After preliminary cleaning, the collection team collected 5 pieces of about 5,000 mature seeds according to the individual plants of bamboo goat milk seeds. These seeds have been cleaned, tested and imported in accordance with the preservation specifications of the germplasm bank. Library work.

  "Bamboo goat milk has large fruits and very high vitamin C content. It has extremely high ecological and economic value. After artificial development, it can be used as fruit and vegetable beverages." said Dr. Ji Yadong, seed collector of the Wildlife Germplasm Bank of Southwest China .

  In this tiankeng, the collection team also collected the germplasm resources of a variety of rare species such as Primula, Begonia, Stone Butterfly, and Koala.

"I believe that in the near future, we will have new results published, which will bring you more surprises." Zhang Ting said.