Soils on slopes: Catenas

Abstract

Hillslopes form a significant part of Earth's surface, and the soils formed across them vary in systematic ways. The predictable pattern of soils in relation to hillslope position is captured in the soil catena concept, which proposes that soil pattern evolves in a deterministic sense in relation to changes in soil and hillslope processes, as modulated by hillslope form. Important hillslope processes include the formation of mobile soil material from underlying consolidated material (soil production) and its transport. The rates of these processes determine the age distribution of the assemblage of minerals making up the soil (the time factor) and the opportunity for vertical and lateral soil differentiation. Movement of water across and through the soils differentially moves dissolved and dispersed soil materials according to their mobility. The concentration of water (especially groundwater) in different parts of the hillslope according to elevation and hillslope form also determines the soil moisture regime.