podzol or spodosol in western germany

acid acidic aging albic alternative barren bleached decompose decomposition dirt dry dune ecosystem eluvial eluviation forest geology germany hardpan humus illuvial layer leaching medieval mineral moraine ortstein ortsteinic overlaid particles pedon perspective podsol podsolization podzol profile protection quartz sand shifting soil solum spodic spodosol subsoil topsoil trees wandering washout weathered western