The formation of soils. Pedogenic processes are soil-forming processes. See Foss (2006) Soil Sci. 171, 6, Suppl. 1 on milestones in pedogenesis. The chief pedogenic factors are time, hydrology, parent rock, climate, fauna and flora, and terrain, but terrain variables may be ineffective predictors of soil characteristics where a dense canopy hides a non-uniform erosional environment (Williamson et al. (2006) Soil Sci. Soc. Am. J. 7). Pedology is the science of soils: their characteristics, development, and distribution.