Though they are thousands of kilometers apart, two parks in the United States and China share sinkhole-dotted landscapes, dark and dripping caves, rare and endangered species – and common enemies in pollution and quarrying.

To preserve their beauty and scientific value, Mammoth Cave National Park, in the southern United States, and South China Karst World Heritage Site, in southern China, are becoming sister parks. This informal relationship will allow for cooperation on mutual goals, including resource management and environmental education, so that future generations can study and enjoy the parks.

An official sister-park signing ceremony was held in Beijing on August 17, 2009.

SCIENTIFIC VALUE OF KARSTS

Mammoth Cave National Park in Kentucky has the longest known cave system in the world, stretching more than 585 kilometers. There are also scenic rivers and lush old-growth and secondary forests. The park was established by the U.S. National Park Service in 1941. In 1981, it was recognized as a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site.

South China Karst World Heritage Site consists of three sub-areas: Libo, Shilin and Wulong. The sub-areas offer a variety of topographical features, from the stone forests of Shilin to the natural bridges of Wulong. The park was recognized as a UNESCO World Heritage Site in 2007.

Similar chemical processes form the distinct landscapes, known as karst topography, of the two parks. Acidic water dissolves layers of limestone at the surface of the ground, resulting in shallow sinkholes or towering rock columns. Water also seeps under the soil, carving underground cave systems with soaring stalagmites and stalactites.

Karst landscapes differ because of geology and climate. In regions that experience short and intense periods of rainfall, such as southern China, more limestone is dissolved and deeper sinkholes result. At Mammoth Cave, rainfall is distributed throughout the year, so sinkholes are shallower.

Both parks are home to rare plants and animals that uniquely adapt to survive in their karst environments. Caves are host to species that thrive in low-energy environments, where there is little food or light.

There are several reasons why karsts should be preserved, according to Rick Toomey, director of Mammoth Cave International Science and Research.

By studying plants and animals that adapt to karsts, scientists can better understand how evolution occurs, Toomey said. Scientists can observe how organisms work together in low-energy sites. For example, bacteria that scavenge carbon from unusual sources, such as karsts, may have other practical applications, such as breaking down pesticides.

Scientists can also gauge pollution levels and observe how species react to toxins in water by studying karsts, Toomey said.

Finally, many people depend on karst groundwater for their drinking supply, Toomey said. For example, nearly 2 million people in San Antonio, Texas, drink water from karst aquifers, as do many millions of Chinese.

PRESERVING THE PARKS

Groundwater pollution and quarrying are the greatest threats to karsts around the world, Toomey said.

Until the 1970s, it was common for cities to dump sewage or gasoline into karsts, he said. In Bowling Green, Kentucky, in the mid-1980s this practice was so widespread that harmful vapors from leaking gasoline would seep up from the caves into homes and basements, forcing many buildings to be evacuated.

Karst landscapes are also threatened by limestone quarrying, Toomey said. Limestone is mined in open pits, for use as building materials, which can destroy animal habitats and pollute water with dust and debris.

Both parks already receive assistance from UNESCO. The parks were designated as World Heritage sites for their exceptional beauty and significant geomorphic features. World Heritage sites receive aid, emergency assistance and technical training for employees in order to preserve the sites.

Mammoth Cave National Park is also recognized as a Biosphere Reserve by UNESCO because its diverse wildlife and ecosystems contribute to scientific study of conservation and sustainable development.

INFORMAL BUT PRODUCTIVE RELATIONSHIPS

Unlike UNESCO designations, the sister-park arrangement between Mammoth Cave National Park and South China Karst World Heritage Site will be informal.

“Sister-park relationships are no- or low-cost frameworks for an exchange of best practices and lessons learned in national parks management,” said Rudy D’Alessandro of the National Park Service.

The parks will share managerial, technical and professional knowledge, as well as information, data, technology, training and experience. For example, the U.S. Agency for International Development (USAID) will hold a workshop to train U.S. and Chinese park employees about management of karst resources, Toomey said. Through collaboration, the parks hope to preserve their karst landscapes and the unique species that live there, as well as learn new methods from their international partners.

Past sister-park relationships have been successful, D’Alessandro said, noting the partnership between Big Cypress National Preserve in Florida and Laguna del Tigre National Park in Guatemala. Because Laguna del Tigre has fewer resources available, its staff practices low-cost, low-tech methods of park management, which they share with the staff of Big Cypress. In exchange, the Big Cypress staff lends technical assistance to Laguna del Tigre.

“Sister-park relationships continue the 90-year history of the [U.S. National Park Service] learning and adapting park management functions from the Swiss, the Costa Ricans and the Japanese, among many counterparts, that have become integral features of the U.S. park experience,” D’Alessandro said.