Effects of Vegetation on the Distribution of Carbon, Iron, and Aluminum in the B Horizons of Northern Appalachian Spodosols
1976
De Kimpe, C. R. | Martel, Y. A.
The effects of coniferous and deciduous vegetation on the distribution of C, Fe, and Al oxides in the B horizons of 10 Podzolic (Spodic) soils of the Northern Appalachian Mountains were investigated. Organic C was extracted with 0.5N NaOH. Iron and aluminum oxides were extracted with pyrophosphate and with dithionite-citrate-bicarbonate. Significantly more Fe and Al was found under conifers than under deciduous trees in the upper part of the B horizon. Aluminum content was also higher in the lower part of the B horizon. After fractionation of the organic matter, fulvic acids appeared as the most important fraction. They contained on the average 52% of the C and > 90% of the Fe and Al involved in organo-metallic complexes. These were found in significantly greater amounts in the upper part of the B horizons of soils developed under conifers. The content of sesquioxides in organo-metallic complexes is a criterion for the classification of the Spodic or Podzolic B horizon in both the US and Canadian systems of soil classification. Variations in sesquioxides due to vegetation type may exclude some Podzolic soils of the Northern Appalachian Mountains developed in fine-textured material of being classified as Spodosols in the US system.
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