Definition: Atlantic Coast Restingas, ecoregion. Vegetation complex ocurring in the seaside lowlands of Brazil, establishing over sea deposits of sandy sediment. It comprises open or scrubby profiles nearer the beaches, while inland it is forms tall forests.
Definition: A group of hydrous aluminium phyllosilicate (phyllosilicates being a subgroup of silicate minerals) minerals (see clay minerals), that are typically less than 2micrometres in diameter. Clay consists of a variety of phyllosilicate minerals rich in silicon and aluminium oxides and hydroxides which include variable amounts of structural water.
Definition: Organic matter in soil which has reached a point of stability, where it will break down no further and might, if conditions do not change, remain essentially as it is for centuries, or millennia.
