Cryptopodzolic Soils in Switzerland

Abstract

Cryptopodzolic Soils are characterized by a thick blackish-brown mineral horizon rich in organic matter, the dark colour of which masks the morphological characteristics of podzolization. Little is known about the specific site factors that lead to the formation of these soils. Four representative soil profiles from a typical toposequence between 1700 and 500 m above sea level in southern Switzerland, embracing Haplic Podzols, Humic Cambisols and Cryptopodzolic Soils, are described morphologically, chemically and physically. The Cryptopodzolic Soils in this region are characterized by weak to moderate A1 and Fe translocation, and by a uniform incorporation of organic matter deep into the soil. The most prominent feature is the exceptional stability of the soil organic matter with a maximum in the spodic horizon. All these characteristics can be explained by the unique combined effect of a mild, wet climate, an Fe-and Al-rich acid bedrock and a litter layer providing dissolved organic matter rich in polyphenolic substances with strong metal-binding properties.

Vegetation patterns maintained by cattle grazing on a degraded mountain pasture

“…This may apply to Alpe Nisciora, where the atmospheric input of N is high due to the proximity of the heavily industrialised region of Milan (110 km to the south). These high N inputs together with the particular chemistry of cryptopodzolic soils (Blaser et al 1997) may also explain why the soils of Alpe Nisciora have rather low C/N ratios compared with similar vegetation in other regions (Gisi and Oertli 1981;Aerts et al 1995;Müller et al 2003;Turner et al 2003), and why N availability did not seem to differ among vegetation types.…”

“…The underlying rock area consists of mixed biotite-plagioclase gneiss (Reinhard et al 1962). Soils range from acidic brown-earth to cryptopodzol (a regional soil type characterised by strong acidity and a high content of recalcitrant organic matter; Blaser et al 1997). A fine, silty texture with strong water repellence makes these soils particularly prone to desiccation and erosion under the prevailing irregular rainfall regime.…”

Preservation of fire-derived carbon compounds and sorptive stabilisation promote the accumulation of organic matter in black soils of the Southern Alps

“…Soils of Southern Switzerland are often characterised by a black colour throughout the profile down to the parent material (Blaser et al, 1997). These soils occur mainly under forests dominated by chestnut trees (Castanea sativa) at elevations below 1000 m asl.…”

“…Blaser et al (1997) classified these soils as Cryptopodzols. They have features of Podzols because pedogenic oxides were eluviated from the topsoil, but the typically bleached eluviation horizon is masked by a dark soil colour.…”

“…They have features of Podzols because pedogenic oxides were eluviated from the topsoil, but the typically bleached eluviation horizon is masked by a dark soil colour. Blaser et al (1997) explained the high amounts of SOC and the dark colour with the presence of both tannin-rich chestnut litter and aluminium (Al) and iron (Fe) in the parent material. The very low bulk density (< 1 g cm -3 ) of Cryptopodzols and the humid climate of the Southern Alps promote the leaching of dissolved organic carbon, including tannins and other polyphenols, from the litter layer through the soil profile, where the organic matter readily forms organo-metallic complexes with Al and Fe oxides.…”