The Importance of Karst Ecosystems

A toast to the underground world! -- Mayor Dani Joy welcomes participants to The Nature Conservancy's International Karst Conservation Workshop held at the Crescent Hotel. Through Friday, Conservancy staff, partners and experts from six U.S. states, Mexico, Dominican Republic, and China are gathering in Eureka Springs to develop conservation plans for several significant karst areas world-wide. For more information about the karst environment visit www.lovelycitizen.com. (Photo by Francie Smith) [Order this photo]

Karst ecosystems are significant global land types, covering

approximately 12% of Earth's land surface. These landscapes develop on carbonate sedimentary rocks where infiltrating fresh waters dissolve and enlarge pre-existing fractures in bedrock. Often they contain caves, sinkholes, sinking streams, and springs, and may contain landforms such

as precipitous limestone towers (e.g. tower karsts of China) or alternating cone-shaped depressions and rises (e.g. cockpit karsts of Jamaica). In the U.S., karst occurs in 48 of 50 states, covering 20% of the country. In other countries, this percentage can be higher. For

example, in Slovenia, over 44% of the land is karst. In Southeast Asia,including Indonesia, karst covers an area around 400,000 km2. Important karst systems occur on every continent (except Antarctica)in both temperate and tropical areas, and these landscapes span a range of biomes from coastal to alpine. Unique to karst, the porous, fractured

nature of the terrain creates a direct connection between surface and subsurface environments.

A diverse group of organisms can be found on karst, and these species are among the world's rarest and most endangered fauna. Many of the surface and subterranean biota are under-protected in the existing network of preserves, and they dominate international conservation concern lists. Subterranean fauna represents more than half of imperiled species listed in the U.S. Natural Heritage Program, yet less than 4% have federal protection status. Due to the endemic nature of many karst species, loss or alteration of habitat can have drastic impacts on populations. In the U.S., at least six karst species are thought extinct

due to human activities. Globally, the number of extinct karst species is unknown.

Similar to karst species, humans are also dependent on karst ecosystems. About 25% of the world's human population relies on karst for drinking water, including about 40% of the U.S. population. Agriculture and forestry benefit economically from colonies of cave bats that consume enormous quantities of insects and thereby reduce insect damage to crops and forests.

Because of the importance of karst ecosystems for humans and biodiversity, The Nature Conservancy is addressing karst conservation by developing strategies, conservation tools, and training courses. The workshop held over the next few days is a prime example. Conservancy staff, partners, and

experts from six U.S. states, Mexico, Dominican Republic, and China are here in Eureka Springs to develop conservation plans for several significant karst areas world-wide.