Tropical Soils and their Origins

Origins and Maintenance of Tropical Biodiversity

Contents 1. Introduction 2. Tropics: description, climate and ecosystems 3. Earth's biodiversity 4. Why are there so many different kinds of organisms in the Tropics? 5. Latitudinal gradients in species richness and their hypothesis 5.

Ophiolites and Their Origins

Ophiolites are the remnants of ancient oceanic crust and upper mantle that were tectonically emplaced into continental margins. They display the only evidence for magmatic, tectonic, and hydrothermal processes associated with seafl oor spreading prior to 170 Ma because no oceanic lithosphere older than this age is preserved in the modern oceans. The occurrence of sheeted dikes, side-byside tabu...

NORM sources and their origins.

Naturally Occurring Radioactive Materials, often referred to by the acronym NORM, are and always have been a part of our world. Our planet and its atmosphere contain many different naturally occurring radioactive species, and it and virtually everything, living or inanimate, contains NORM. In the history of mankind, knowledge of the existence of radioactivity is very recent, even when considere...

Agrochemicals and Bacterial Diversity in Cultivated Tropical Soils

Sequential sorption of lead and cadmium in three tropical soils.

It is important to examine mechanisms of Pb and Cd sorption in soils to understand their bioavailability. The ability of three tropical soils to retain Pb, Cd, and Ca was evaluated. The objectives of this study were to (1) determine the extent to which soil sorption sites are metal specific, (2) investigate the nature of reactions between metals and soil surfaces, and (3) identify how metals co...