One Hole, One New Species: Rescue Karst Cave Creatures

In 2017, researchers conducted a karst cave expedition in Guizhou. Duan Yifan courtesy of the picture

Guilin, with its typical karst landform, is famous for its landscapes. When people visit those natural karst caves, they can think of the caves that can't see the fingers, but also have a rich, diverse and unique biological community.

However, the biodiversity of karst caves in southwest China is under serious threat.

Recently, Science magazine published a review article entitled "Protecting The Karst Cave Habitat of China" online, calling for attention to the conservation of biodiversity in karst caves, which has attracted the attention of the academic community.

Unique biomes in the dark

"China has a very vast and typical karst landform, which is home to a large number of endemic species and is one of the most biodiverse areas in the world." Duan Yifan, the first author of the paper and an associate professor at Nanjing Forestry University, told China Science Daily that karst landform (Karst Landform) is a landform formed by the dissolution and precipitation, erosion and sedimentation of soluble rocks by groundwater and surface water, as well as gravitational collapse, collapse, accumulation and other effects, which is also known as karst landform in China.

Karst landforms are divided into two categories: surface and underground, the surface has stone buds, lyssed ditches, karst funnels, sinkholes, dissolution depressions, karst basins and karst plains, peak clusters, peak forests and lone peaks; underground caves, underground rivers, dark lakes and so on.

The author of the paper, Associate Professor of Nanjing Forestry University, Xu Wang, said in an interview with China Science News that the world's typical karst belt is the karst belt in central and southern Europe (Alps, Russian Ural Mountains), the eastern Karst Belt in North America (Indian State, Kentucky in the United States) and the southwest karst belt in China (Yunnan-Guizhou Plateau, Xianggui Hills, Qinghai-Tibet Plateau).

"One of the characteristics of the karst region is that it has a large number of caves and hidden rivers, and it is inhabited by a wide variety of biological groups." Permission Wang said.

"Dark caves are just a form of karst landscape." Li Meng, author of the paper and lecturer at Nanjing Forestry University, said that caves are topographies and landforms with well-shaped or barrel-shaped enclosed spaces and morphological characteristics surrounded by steep rock walls. Its interior light, temperature and humidity are relatively stable, creating excellent habitat conditions for the growth and breeding of organisms in the pit, while the interior of the cave is mild and humid, maintaining a high species diversity.

In addition, "the cave effectively reduces the external disturbance of the sinkhole ecosystem, making it a shelter for the survival of many endangered animals and plants, and also creating a unique biological structure and diversity of the sinkhole ecosystem." Li Meng said.

Some researchers have conducted preliminary biodiversity investigation and research on some caves in the Jingxi Karst area of Guangxi, and found that 5 species of blind fish, 1 species of blind shrimp, 2 species of pseudo-scorpions, 4 species of blind walking nails, 2 species of ant beetles, and 1 species of moss nails are all rare cave biological groups.

Duan Yifan introduced that according to the existing surveys, the species diversity of karst caves is rich. From low plants algae, microorganisms, ferns (such as ear ferns), flowered plants (such as begonias), to invertebrates (such as spiders, horses, panza horses, centipedes), vertebrates (such as blind fish, hawkfish), etc., there are many kinds.

"In general, the eyes of cave animals are visibly degenerated and lack pigmented." For example, the all-translucent Wulong lilac loach discovered in 2005 in Wulong County, Chongqing, has no eyes and generally lives in caves underwater. An ornamental fish, the Mexican carp, also has no eyes.

Researchers believe that it may be because food is scarce in the caves, so the animals sacrificed their eyes, which consume a lot of energy. "Anyway, the hole is dark, and it's not very useful." If something falls into the cave, it eats. Li Meng said.

"One mountain and one new species, one hole and one new species"

Biodiversity is related to human well-being and is an important foundation for human survival and development.

My country is one of the countries with the richest biodiversity and one of the countries with the most serious threats to biodiversity. Among the higher plants, 4,000 to 5,000 species are threatened, accounting for nearly 20% of the total number of species. Of the 640 endangered species listed in the Convention on International Trade in Endangered Species of Wild Fauna and Flora, about 24% are endangered in China, and the situation is very serious.

Among them, "China's karst area is one of the most threatened areas of global biodiversity." Permission Wang said.

Allow Wang told China Science Daily that the ecological environment in karst areas is special and extremely fragile, and its vegetation is extremely difficult to restore once it is destroyed, and it is a fragile ecosystem that is vulnerable to interference, with poor ecological stability, and has been identified by academia as one of the world's major ecologically fragile areas.

"The fragile karst ecological environment, coupled with the interference and destruction of human activities, has led to the continuous intensification of rocky desertification." The first threat, Mr. Qan said, is habitat loss and fragmentation. Limestone is the main component of karst landforms and is also an important building raw material. Its low price and versatility are essential for economic development. However, over-exploitation of limestone will inevitably cause damage to the karst ecological environment.

Second, biodiversity conservation is disturbed by a wide variety of human factors. For example, reclamation and reclamation, irrational planning of tourism projects, operational activities and mineral accumulation in mining sites, invasion of alien species and environmental pollution, etc., all pose serious threats and challenges to the maintenance of biodiversity in karst areas.

"Karst caves, in particular, have very special habitats: dim light, high humidity, small temperature fluctuations, limited nutrient supply, etc., and the biological species that grow in caves tend to have only very narrow distribution areas and very small populations, which need to be protected." Duan Yifan said.

Because the absolute number of typical cave life populations in karst is small, and the relative isolation of caves limits the spread of biological distribution, most typical cave organisms are limited to a single hill or a single cave, According to Zhangwang. There was once a phrase describing the biodiversity of karst areas: "one mountain and one new species, one hole and one new species", which is enough to show that the species diversity of this habitat is high.

Many of the creatures in karst caves became vulnerable species. For example, in fish, duck-billed golden-rayed catfish, hunchbacked golden-line catfish, eyeless golden-lined catfish, small-eyed golden-line catfish, horned golden-rayed catfish, transparent golden-threaded catfish, rhinoceros-horned golden-threaded catfish, old blind plateau loach, Yunnan plateau loach, stone forest blind plateau loach, etc., because of the small number of populations, are listed as vulnerable species.

Many plants that grow in caves, especially ferns, are basically only distributed in a single cave, and the population is easily destroyed. For example, it is only distributed in a cave next to a small town in Pingguo County, Guangxi Province, with a small population of less than 100 plants, and no more distribution points have been found in multiple surveys.

"These populations are vulnerable to human disturbance and destruction, or even extinction, so they need to be protected." Permission Wang said.

Governments and the public should act hand in hand

"Government, civil society institutions and public science education are crucial to the conservation of karst biodiversity. The government can increase protection in supporting measures such as laws, systems and financial inputs; the various conservation practices, demonstrations and experiments of non-governmental environmental protection institutions can also provide useful references and bases for new ideas and new methods of karst biodiversity conservation, and provide a platform and bridge for rising public participation. Duan Yifan said.

Li Meng introduced that with the help of the coordination capacity and scientific assessment methods of global non-profit environmental protection agencies such as the World Union for Conservation of Nature (IUCN), scientific assessments should be carried out on the protection and restoration of species and ecosystems in China's karst areas, rescue endangered species of animals and plants, and establish karst national parks and protected areas.

In addition, they believe that the spurt of public science education in recent years has become an emerging industry and market demand in the field of protection, which has also stimulated the improvement of public awareness of ecological protection and promoted a benign change in people's understanding of the value of nature and the relationship between man and nature.

Today, public participation is an important force in promoting conservation measures in many protected areas and government agencies, such as ecological stewards in major protected areas, who patrol and manage biodiversity to improve conservation effectiveness while benefiting local people. Through nature experience activities operated by local people's cooperatives, local communities and foreign visitors can share the benefits of protection, which is one of the important ways to transform "green waters and green mountains" into "golden mountains and silver mountains".

Source: Science Network