Linear regressions between the sum of oxalate-extractable aluminium and iron (Alox+ Feox) and the Sorption Index with phosphorus (P) fractions in humus soils along an elevational gradient in Abisko, Sweden.

Values are for heath and meadow vegetation data combined. Degrees of freedom for all P pools are 1,46 for Alox+Feox; and 1,45 for the Sorption Index due to one missing value.aSum of Resin P, Bic-extractable Pi and Bic-extractable Po.bSum of all sequentially extracted P fractions.