Subalpine Loamy Spodosols in Taiwan: Characteristics, Micromorphology, and Genesis

Abstract

AbstractFour subalpine loamy Spodosols with illuvial clay in the spodic horizons were selected for study to understand their characteristics, micromorphology, and genesis. These Spodosols, located in central Taiwan, are covered by coniferous vegetation, receive high levels of precipitation, and occupy gentle slope positions at elevations >2400 m. Soil textures, which range from loam to clay, are finer than those of Spodosols formed in temperate regions. The pedogenic products in the soils of the study area are mainly organo‐metallic complexes or illuvial clay mixed with organo‐metallic complexes in the spodic horizons. Typical micromorphological features in the spodic horizons of these Spodosols revealed infillings of organo‐Fe complexes, argillans, or argiferrans along the irregular voids. The four selected pedons have loose spodic horizons where illuvial clay also has accumulated. The large amounts of spodic materials and illuvial clays in the spodic horizons indicate that podzolization and clay accumulation were the two dominant pedogenic processes. Some of the illuvial clay translocated into the spodic horizons is mixed with organo‐Fe (or ‐Al) complexes along the irregular voids of the spodic horizons. This may also have resulted in a lack of well‐oriented clay in these horizons despite the occurrence of large amounts of illuviated clays.