Project 448: World Correlation of Karst Geology and Relevant Ecosystems

From the results of IGCP 299 and IGCP379 it was recognized that ecosystems in the karst regions of the world, with a population exceeding one billion, are fragile, and characterized by calciphiles, petrophiles, xerophiles, and a subterranean ecosystem as a result of the karst hydrological system and Ca-Mg rich geochemical background. However, the impact on human life is quite different in different karst regions with varied ecological features. For instance, intensive karstification and underground drainage can bring about serious ecological problems, such as the rock desertification in the southwest China karst. However, in some boreal or temperate humid karst regions, underground hydrological systems are beneficial to forest or agriculture. A global comparison of karst ecosystems has revealed knowledge on the mechanisms of how different karst ecosystems function and evolve. This understanding makes feasible a more reasonable treatment of ecological problems and sustainable development in karst. Project 4 48 has therefore been in keeping with the guideline of IGCP: "Geoscience in the service of society".

The achievements of Project 448 can be summarized in line with the four objectives of the Project.

(1) World Comparison of Karst Ecosystems

Field comparisons between karst ecosystems were carried out by the Project in Northwest Romania; Lagoa Santa Karst of Eastern Brazil; China (a North to South transect), Spain and Bulgaria. Meanwhile, the IGCP 448 National Working Groups from other European countries, Africa, East Asia, the Middle East and Latin America have provided data of karst ecosystems of their own countries. Thus the Project obtained good case examples to understand the characteristics and differences of karst ecosystems under different climatic conditions (subtropical and tropical, Asia Monsoon, the Arabian sea semiarid, cold temperate and Mediterranean), and various geological backgrounds, (intraplate, Gondwana, arc-Islands, Tethys, and different lithological features of soluble rocks : porous or hard compact).

(2) Geology and Karst Ecosystems

Relict species of the Glacial Stages and Tertiary and Cretaceous periods were identified in the vegetation of Romania, Southern Spain, and the Southern China Karst. Species of medicinal herb in the subtropical karst in China are found to be calciphiles and related to the migration of some trace elements. The breaking of the Bosporus Strait and invasion of Mediterranean salt water 7600 years ago brought about mass killing of fresh water organisms in the Black Sea karst ecosystem, as evidenced by a 2m thick sapropel in Bulgaria. Calciphile species growing on the limestone areas in Southern Spain include olive oil trees and Quercus. The latter is good for feeding a type of pig that is the source of a famous ham. The karst ecosystem in Alicante, SE Spain has been deteriorated by increasing SO4- content in the water, which is related to gypsum beds in depth.

(3) Subterranean Karst Ecosystems

Subterranean ecosystems based on chemoautotrophic microorganisms were studied in Movile Cave, Romania, and Villa Luz Cave, Mexico. Subsoil bacteria in karst ecosystems of South China, including those that can produce Carbonic Anhydrase and accelerate karst processes, were screened. Iron-mineralizing bacteria which prefers a dry condition were identified in Odyssey Cave, NSW, Australia. Microbial communities in Altamira Cave, N. Spain are found responsible for the formation of carbonate coating and moonmilk deposits, and thus damaging prehistoric arts in the Cave. It was revealed that the Iron Ochres in the Ochtinska Cave, Slovakia are an important regulator of cave humidity by releasing and absorbing air moisture. A green algae in Bonne-Cougne karst pond, Var, Southern France is believed responsible for the progressive decrease of sulfates in the water. Systematic study on cave animals in the Zhenjiadadong Cave, Guizhou, S.China was carried out.

(4) Impacts of Human Activities on Karst Ecosystems

Many case studies in this direction were done by IGCP 448 members in the past three years, such as the impacts of limestone quarrying on groundwater, soil, vegetation in Lagoa Santa karst of Brazil; pollution of the atmosphere by the Idrija Mercury Mine of Slovenia; the effect of planting imported species on biodiversity in the Stone Forest area, Yunnan Province, S China; the impacts of oil leakage along highway on a karst hydrological system in Kentucky, USA; the contamination of a karst aquifer by the leachate from the urban solid waste landfills at La Mina, Marbella, Spain, and Merida,Yucatan, Mexico. Data from systematic monitoring in Nerja Cave, Malaga, Spain shows that the annual variation of PCO2, temperature, and humidity in cave are mainly due to natural factors (PCO2 in soil, drip water flow rate, and natural ventilation in cave), but from a daily scale, they are mainly related to human factors, because each person entering a cave can emit an average of 70 watt of energy, 50g of water vapor, and 20 litres of carbon dioxide per hour. Sea water intrusion has happened in some karst aquifers in coastal areas following water overexploitation, such as in the the Campo de Dalias aquifer (Triassic limestone and dolomite) in Almeria, SE Spain. The results of karst system vulnerability assessments were achieved by French and Swiss members of the Project in Jura region.

IGCP 448 List of Publications (Project is still underway)

1. Liu, Z, and J.Zhao, 2000, Contribution of carbonate rock weathering to the atmosphere CO2, Environmental Geology 39:1053~1058.
2. Linan-Baena, C., B.Andreo-Navarro, F. Carrasco-Cantos, and I. Vadillo-Perez, 2000, Consideraciones acerca de la influencia del CO2 en la hidroquimila de las aguas de goteo de la Cueva de Nerja (Provincia de Malaga). Geotemas 1341~344.
3. Liu, Z., D.Yuan, S. He, and M. Zhang, 2000, The geochemical characteristics of geothermic CO2-H2O-Carbonate System and the Source of its CO2. Science in China (Series D), 30:209~214.
4. Yuan, D. 2000, On the karst ecosystem: IGCP 448, in Proceedings of the Joint meeting of Friends of Karst and IGCP 448, Bowling Green, Kentucky USA, p. 13.
5. Ford, D., 2000, Geology, climate, glaciation and antecedence in a sample of Canadian Karst, in Proceedings of the Joint meeting of Friends of Karst and IGCP 448, Bowling Green, Kentucky USA, p. 64.
6. Porter, M.L., 2000, Movile cave: Modeling ecosystem energetics in sulfidic karst, in Proceedings of the Joint meeting of Friends of Karst and IGCP 448, Bowling Green, Kentucky USA, p. 97-100.
7. Manolache, E., 2000, Methanotrophic Bacteria in Movile Cave, in Proceedings of the Joint meeting of Friends of Karst and IGCP 448, Bowling Green, Kentucky USA, p. 79.
8. Tamas, T., 2000, Mineralogy and microbiology of black deposits from Cuciulata Pothole (Bihor Mountains, Romania), in Proceedings of the Joint meeting of Friends of Karst and IGCP 448, Bowling Green, Kentucky USA, p. 140-147.
9. Berbert-Born, M.L., 2000, Bottom sediments from lakes of the Lagoa Santa region, Minas Gerais, Brazil, in Abstract Volume of the 31st International Geological Congress.
10. Velasquez, L.N.M., 2000, Geology and hydrogeology applied to self-sustained development for the Karst of Arcos-Pains-Dorepopolis, M.G., Brazil, in Abstract Volume of the 31st International Geological Congress.
11. Pereira, R. G. F. A et al, 2000, Karst Geomorphology and geospeleology of the Una River Basin, Eastern Chapada Diamantina, Bahia, Brazil, in Abstract Volume of 31st International Geological Congress.

The Final Report for Project 448 is currently being prepared for publication in 2005.

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