South China Karst Be A Part of World Natural Heritage
Karst landforms develop at small, intermediate, and large scales. Karren is the general name given to small-scale forms-varieties of dissolutional pits, grooves, and runnels. Individuals are rarely greater than 10 meters (30 feet) in length or depth, but assemblages of them can cover hundreds of square kilometers. On bare rock, karren display sharp edges; circular pits or runnels extending downslope predominate. Beneath soil, edges are rounded and forms more varied and intricate.
Sinkholes, also known as dolines or closed depressions, are the diagnostic karst (and pseudokarst) landform. They range from shallow, bowllike forms, through steep-sided funnels, to vertical-walled cylinders. Asymmetry is common. Individual sinkholes range from about 1 to 1000 meters (3 to 3,300 ft) in diameter and are up to 300 meters (1,000 ft) deep. Many may become partly or largely merged.
Dry valleys and gorges are carved by normal rivers, but progressively lose their water underground (via sinkholes) as the floors become entrenched into karst strata. Many gradations exist, from valleys that dry up only during dry seasons (initial stage) to those that are without any surface channel flow even in the greatest flood periods (paleo-valleys). They are found in most plateau and mountain karst terrains and are greatest where river water can collect on insoluble rocks before penetrating the karst (allogenic rivers).
Poljes, a Serbo-Croatian term for a field, is the generic name adopted for the largest individual karst landform. This is a topographically closed depression with a floor of alluvium masking an underlying limestone floor beveled flat by planar corrosion.
Karst plains and towers are the end stage of karst topographic development in some regions, produced by long-sustained dissolution or by tectonic lowering. The plains are of alluvium, with residual hills (unconsumed intersinkhole limestone) protruding through. Where strata are massively bedded and the hills are vigorously undercut by seasonal floods or allogenic rivers, they may be steepened into vertical towers.
The South China Karst region
The South China Karst region extends over a surface of half a million square kilometers lying mainly in Yunnan, Guizhou and Guangxi Provinces. South China is unrivalled for the diversity of its karst features and landscapes. The site presents a coherent serial property comprising three clusters: Libo Karst, Shilin Karst and Wulong Karst. South China Karst represents one of the world's most spectacular examples of humid tropical to sub-tropical karst landscapes. The stone forests of Shilin are considered superlative natural phenomena and a world reference. The cluster includes the Naigu stone forest occurring on dolomitic limestone and the Suyishan stone forest arising from a lake. Shilin contains a wider range of pinnacle shapes than other karst landscapes with pinnacles, and a higher diversity of shapes and changing colours. The cone and tower karsts of Libo, also considered the world reference site for these types of karsts, form a distinctive and beautiful landscape. Wulong Karst has been inscribed for its giant dolines, natural bridges and caves.
It is a typical site of cone karst on the transitional zone between Guizhou plateau and Guangxi lowland, outstanding for their full spectra of gradual change from plateau karst to the lowland karst. The cone karst landscape supports immense biodiversity and this special karst forest ecosystem is the habitat of many endemic species and endangered fauna.
The nominated sites, where 90 percent of their populations are minorities, are rich in culture. The exotic local minority culture is the colorful and unique ethnic groups of Shui, Yao, Buyi, etc. The delimitation of boundary for the Libo Karst Nominated Sites mainly accords to the integrality of cone karst geomorphology development and distribution, karst forest ecosystem and habitat of rare and endangered species. The boundary keeps coherence with the boundary of Maolan National Nature Reserve and Daqikong and Xiaoqikong Spots in Libo Zhangjiang National Scenic Area.
The Libo Karst comprises core area of 29,518 hectares and buffer zones of 43.498 hectares. The core area of the Maolan National Nature Reserve nominated site covers 21,684 hectares taking up 73.46 percent of the cone area of the Libo nominated sites.
The criteria satisfied for the World Natural Heritage is as below:
Be outstanding examples representing major stages of the earth evolutionary history, including the records of life, significant on-going geological processes in the development of landforms, or significant geomorphic or physiographic features.
Be outstanding examples representing significant on-going ecological and biological processes in the evolution and development of terrestrial, fresh water, coastal and marine ecosystems and communities of plants and animals.
Contain the most important and significant natural habitats for in-situ conservation of biological diversity including those containing threatened species of outstanding universal value from the point of view of science or conservation.
Over the past 300 million years the Stone Forest area has experienced a vicissitude from sea to land, from lowland to plateau as a result of earth movement. The initial carbonate rock which formed in ocean was wizardly shaped into "stone forest" landform. During its evolution the Stone Forest were once covered respectively by fiery volcanic lava and lake water, in this sense the formation of the Stone Forest is truly a geologic legend in the world.
The Stone Forest displays the richest morphological features. Due to its unique geological evolution, numerous stone forest clusters that formed in different geological periods coexist in varied topography, each with its particular features. There are pinnacle-shaped, column-shaped, mushroom-shaped, and pagoda-shaped groups. Since almost all the typical pinnacle karst types can be identified in the Stone Forest, the park is acclaimed internationally the "Museum of Stone Forest karst."
Walking through the Stone Forest, visitors marvel at the natural stone masterpieces and are bewitched by the intricate formations. The magnificent, strange and steep landscape creates countless labyrinthine vistas, including: Major Stone Forest, Small Stone Forest and Naigu Stone Forest, all of which feature stones in various formations. Animals, plants, and even human figures can be found here. Some are elegant, some are rugged, and each is lifelike with its own distinguishing characteristics.
Subterranean Stone Forest in Zhiyun Cave, an underground stone forest distributed among several caves and occupying a total area of about 3 square kilometers.
Strange Wind Cave, composed of Penfeng Cave, Hongxi Spring and an underground river. From August to November, gales lasting two to three minutes sweep out of the cave every 30 minutes.
Long Lake is a karsts lake that is three kilometers (two miles) long but only 300 meters (zero point two miles) wide. The lake features underwater stalagmites and stalactites and a small island in the center of the water.
The source of the Dadie Waterfall, Ba River, is a branch of Nanpan River. In the rainy season, up to 150 cubic meters (196 cubic yards) of water per square inch plummet down the 88 meter (288 feet) drop.
Every year, around the 24th and 25th day of the sixth lunar month, the Sani people gather in the Stone Forest to celebrate their "Torch Festival." Visitors are welcome to enjoy the folk dances and the wrestling competitions of the Sani youngsters.
The macro-landform in this terrain is featured by two-leveling mountain planes with elevations of 1,800-2,000 meters and 1,200-1,500 meters and deep-cut gorges. The three karst systems lie in the bank, interfluve and headstream of Wujiang River branches respectively; and they formed an interrelated integrity for its developing successively and distributing in sequence.
Wujiang River is one of big tributaries of Yangtze River, with a section of 79 kilometers long in Wulong and an incised depth of one kilometer. It influenced intensely the development of its branches such as Furong Jiang, Yangshui He, Muzong He geomorphic systems, for its continuous river incising and vadose zone increasing since the tertiary, and it is the main dynamic genesis of Wulong Karst.
The Wulong Karst records vividly the unique characters of gorge, cave and tiankeng karst development and evolvement under the intermittence tectonic uplifting conditions in Three Gorges area since Cenozoic era for 65Ma, representing major stages of earth evolutionary history.