Fern

Same species as Brook's step s251 and the soil pH steps (Hydrogen ions); one spelling joins the linktrees of rhizosphere and soil acidification processes. Rhizosphere acidification arises from H+ extrusion when cation uptake exce…

Horizon differentiation moves clay and humus; standardise to Clay minerals and Soil organic matter, the spellings used by the soil structure, CEC and carbon steps, so their linktrees connect to this pedogenic step.

Spelling reuse: the map uses 'Clay minerals' and 'Soil organic matter' everywhere else, so the linktrees for these names miss this step.

Use the map-wide resource name 'Soil organic matter' instead of 'Organic matter' so this step appears in the same linktree as the soil branch.

Water vapour is the dominant volcanic gas (typically most of the gas phase) and is missing from the resources; 'Water vapour' is the spelling used in the water cycle.

How charged clay and humus surfaces hold exchangeable cations and set soil pH and solution chemistry. Covers acidification, buffering, base cation loss, alumin…

How roots, hyphae, polysaccharides, oxides and fauna bind particles into aggregates that give soil its pore network. Covers the hierarchy of micro- and macroag…

How rain enters, is held in and moves through soil. Covers infiltration versus runoff, retention by matric potential, drainage, root uptake and evaporation, an…

How rock and parent material break down physically and chemically into soil minerals, releasing nutrients and forming secondary clays and oxides. Covers carbon…

How nutrients are held, released, taken up and lost in soil. Covers mineralisation, nitrification, phosphate sorption, immobilisation, nitrate leaching and den…

Organic matter, hyphae, roots stabilise structure, which protects organic matter

Microbial loop recycles nutrients