Characteristics and pedogenic processes of podzols in the Selkirk Mountains of Northern Idaho, United States

Abstract

Characteristics and pedogenic processes of two podzols at different elevation from Selkirk Mountains, Northern Idaho were examined. Both pedons were characterized by the presence of organic (O)-albic (E)-spodic (Bhs or Bs) horizon sequence, and classified as Spodosols or Podzols in Soil Taxonomy, WRB and Soil Classification System of Japan (SCSJ). Podzol of the lower elevation (745 m) is located in glacial outwash fan and showed extremely coarse-sandy textures of granitic glacial drift. These conditions were favorable for leaching and moving of soluble organic acids into deeper horizon, leading to promoting podzolization. On the other hand, parent material of the higher elevation podzol (1809 m) is mixtures of coarse-textured glacial drift and 6700-6800-year old volcanic ash from Mt. Mazama (now Crater Lake, Oregon). Cooler and moister soil of higher elevations associated with subalpine fir (Abies lasiocarpa) forest have provided the conditions necessary for development of spodic properties.