Transitional Soil Characteristics of Ultisols and Spodosols in the Subalpine Forest of Taiwan

Abstract

This study examined the illuviation of clay and spodic materials in three Ultic Haplorthods derived from fine-textured materials from the Alishan Mountain of central Taiwan. Soil analysis, including field description, physical and chemical analyses, and micromorphological studies, was used to study the soils. The soil colors are close to 7.5YR 5/6 in all subsurface horizons, with different degrees of spodic material accumulation. Various clay coatings and pellet-like aggregates were found in all subsurface horizons, which satisfied the morphological and chemical criteria for a spodic horizon (Bhs) as defined in Soil Taxonomy. The illuvial clay coatings have relatively weak birefringence but are masked by organo-metallic complexes. Spodosols were found locally to have a thick organic layer, which may intensify the podzolization process. We hypothesized that Fe and Al were chelated by organic matter in the surface portion of the pedon to form organo-metallic complexes. The translocation of clay occurred before the illuviation of organo-metallic complexes in the subsurface horizons during soil development. The slow accumulation of organic-metallic complexes in the Bhs horizons within the 50cm depth is attributed to fine texture and less porosity. The soils derived from two pedogenic processes to show the transitional status between Ultisols and Spodosols that the argillic horizon is overlain by the spodic horizon. (Soil Science 2004;169:457-467

Podzolization over ophiolitic materials in the western Alps (Natural Park of Mont Avic, Aosta Valley, Italy)

“…Its trend is similar to that of Fe o . Similar levels, though infrequent, have already been reported in literature (Hseu et al, 2004) and can be ascribed to the solubility of finely subdivided, inorganic Fe oxides (Parfitt and Childs, 1988), to their mostly organic-bound form, and to the dispersion of some clay particles.…”

Natural speciation of Mn, Ni, and Zn at the micrometer scale in a clayey paddy soil using X-ray fluorescence, absorption, and diffraction

“…Another piece of evidence comes from the abundance of hydroxy-Al vermiculite by X-ray diffraction. This hydroxy-Al phyllosilicate Zn species is probably widespread in acidic soils, and in particular in Ultisols owing to the abundance of vermiculite is these soils (Hseu et al, 2004;Li et al, 1998). This species seems to occur together with lithiophorite, as this latter was identified also in the Pennsylvannia and Ohio soils.…”

“…Polarized EXAFS (P-EXAFS) measurements in combination with powder X-ray diffraction were instrumental in demonstrating the incorporation of zinc in the hydroxy-Al layer of vermiculite. Since hydroxy-Al phyllosilicate is abundant in Ultisols (Hseu et al, 2004;Li et al, 1998), which cover a large part of the earth's surface, this species is likely one of the most abundant forms of Zn in the environment.…”

Geochemical characterization of placic horizons in subtropical montane forest soils, northeastern Taiwan

“…Cool and humid climates appear to be essential for the development of placic horizons. In subtropical regions placic horizons develop only in subalpine soils (Hseu et al , 1999, 2004; Pinheiro et al , 2004; Wu & Chen, 2005), with temperature and moisture regimes similar to those in temperate regions (Crampton, 1963; McKeague et al , 1968; Brewer et al , 1973; Lapen & Wang, 1999; Tonkin & Basher, 2001). These conditions retard the decomposition of plant litter, and this results in the accumulation of soil organic matter.…”

“…In the subalpine and alpine forest ecosystem at higher altitudes, soils show clear illuvial processes and strong chemical weathering because of high annual rainfalls (≥3000 mm). Hseu et al (1999Hseu et al ( , 2004, Wu & Chen (2005) and Jien et al (2010) found podzolic soils and soils with placic horizons in the subalpine cloud forests of northern Taiwan. Ultisols with a placic horizon or Spodosols with large silt and Fe contents have attracted attention elsewhere in Asia (Baillie et al, 1982(Baillie et al, , 2004Nakao et al, 2009a,b).…”