SOIL LAYERS IN MIRES: FUNCTION AND TERMINOLOGY

Abstract

Summary: Two recent North American soil classification schemes embodying criteria for distinguishing layers in mire soils are criticised as being artificial and unrelated to function. In these soils, the most important functional processes are hydrological. The two‐layer hypothesis of K. E. Ivanov, involving a set of hydrological differences and associated biological characteristics, is accordingly advocated as a basis for a natural scheme of layering, in which a surface layer, the ‘active layer’, is distinguished from the ‘inert layer’ below. Since both expressions are deemed inadmissible, it is suggested that the upper layer be termed the acrotelm and the lower layer the catotelm . A two‐layered mire soil should be termed diplotelmic and one without an acrotelm, haplotelmic . Basic definitions for all 4 terms are provided. Possible applications to eroded or reclaimed mires are briefly discussed.