Soil comparison

Which one of these soil clumps is from a wetland? In saturated soils, there is no oxygen available. That means only anaerobic (or oxygen-less) respiration can take place, by bacteria that can use other substances, like Iron, to produce energy. When bacteria metabolize Ferric Iron it converts to its dissolved form Ferrous Iron, which is colorless, turning the soil to its natural base color, often gray. That’s a really long-winded way of saying: it’s the one on the right.