At least potentially karstifiable rocks cover much of the surface of Egypt and northern Libya. Study of caves and other karstic features of this region has been hampered by lack of roads, rapid disintegration of the surface of friable, poorly consolidated limestone, wind-blown sand and other factors. Interbedding with marly aquicludes hampers speleogenesis locally. Calcareous and evaporite kars...

In the absence of sunlight energy, microbial community survival in subterranean aquifers depends on integrated mechanisms of energy and nutrient scavenging. Because karst aquifers are particularly sensitive to agricultural land use impacts due to rapid and direct hydrologic connections for pollutants to enter the groundwater, we examined the fate of an exogenous pesticide (atrazine) into such a...

The distribution characteristics and migration mechanism of seepage field of reservoir groundwater can determine the geographical characteristics of reservoir area to a large extent. The permeability of reservoir area is especially important since it is an important indicator of karst development characteristics and its hydrogeological condition in karst area, and it’s difficult to conduct quan...

Nitrogen (N) deficiency occurs in over 80% of karst soil of southwest China, which restricts regional agricultural production. To test whether N fixed by legumes becomes available to nonfixing companion species, N fluxes between soybean and maize under no, partial, and total restriction of root contact were measured on a karst site in southwest China. N content and its transfer between soybean ...

Cave cricket populations are essential to the survival of many rare invertebrates that are endemic to the karst regions of Fort Hood, TX. These crickets bring organic matter into the caves, where it serves as an energy source for a variety of karst invertebrates. At Fort Hood, Red Imported Fire Ants (RIFA) migrating from South America into the southern United States prey upon cave crickets, whi...

[1] Using an estimated bicarbonate concentration ([HCO3 ]) in water and discharge rates of surface water and underground water from the Houzhai Basin, southwest China, from 1986 to 2007, we estimate that the mean carbon uptake rate was 20.7 g C m yr. The surface water and underground water contribute about equally to the total carbon uptake from 1986 to 2007. About 97% of the interannual variat...

Thick carbonate rocks were developed in the depression of the Tarim craton during the Cambrian-Middle Ordovician periods. The compressional tectonic movement during the Middle Caledonian-Hercynian created the paleouplifts, which became the base for the paleokarst in the Ordovician carbonate rocks. Based on the large quantity of seismic, drilling, and geological outcrop data, this study analyzed...

The Grain to Green Program (GTGP) and eco-environmental emigration have been employed to alleviate poverty and control rocky desertification in the Southwest China Karst region. Carbon sequestration and oxygen production (CSOP) is used to indicate major ecological changes, because they involve complex processes of material circulation and energy flow. Using remote sensing images and weather rec...

ABSTRACT The French Mediterranean coastal aquifers are essentially alluvial, deep sedimentary and karst. Whereas the alluvial aquifers are particularly sensitive to salt-water intru sion, contamination of the deep aquifers is generally due to vertical hydraulic connec tion with the shallow aquifers. As for the karst systems, which are quite well developed f rom Languedoc-Roussillon to Provence-...

Troglobites, or species restricted to caves, commonly have small ranges and high levels of endemism, making them extremely sensitive to relatively small-scale habitat alteration that results from urbanization. Protection of federally listed endangered troglobites in central Texas focuses on caves that are occupied by the species. The determination of occupancy is based on presence/absence surve...