CHARACTERISTICS OF SOIL ORGANIC MATTER IN ECTOHUMUS HORIZONS OF FOREST SOILS IN THE STO£OWE MOUNTAINS

Abstract

This paper describes the fractional composition of humus substances and physico-chemical properties of ectohumus horizons in forest soils (Haplic Cambisols (Distric) and Albic Podzols) developed from various parent materials and in various forest sites: mountain mixed forest witch beech tree, spruce forest witch spruce monoculture, mountain mixed forest witch beech, sycamore maple and larch and mountain mixed forest witch spruce and larch. Reactions of the analyzed soils were strongly acidic. Organic C content was in the range of 21-48% and total N reached values between 0.68-1.63%. The fractional composition of humus substances was analyzed using the Tiurin method. Fraction Ia (extracted with 0.05 mol dm-1 H2SO4) constituted a rather insignificant part (1.03-3.63% of Corg) of humus compounds. Humus was dominated by fraction I (extracted with 0.1 mol·dm-1 NaOH) (27.4 - 42.5% of Corg). The ratio of CHA:CFA was within the range of 0.75-1.35 and increased in deeper organic subhorizons. Non-extracted C was within the range of 55.7-69.7% of Corg. In all the ectohumus samples investigated, the highest humification degree was found in the deepest organic subhorizon.