Skip to main content

Towards a Taxonomic Classification of Humus Forms

Buy Article:

$29.50 plus tax (Refund Policy)


A two-category taxonomic classification and a methodology for field description are proposed to aid in consistent identification and interpretation of humus forms for ecosystem research, surveys, and management. The classification uses the nomenclature principles of the U.S. soil taxonomy and the master organic horizon designations of the Canadian system of soil classification. It includes humus form taxa that have been recognized in Europe and North America. Recognized taxa are defined on the basis of observable and easily measurable morphological properties. Three taxa, Mor, Moder, and Mull, are recognized at the order level and are differentiated according to the type of F horizon and the relative prominence of organic-enriched A horizons. These reflect principal differences in the nature and rate of decomposition processes. Names of the 16 taxa at the lower, group level are created by adding formative elements to the name of the order. For example, groups of the Mor order are differentiated according to the relative thickness of F and H horizons (Hemimors and Humimors); degree of humification in the H horizon (Resimors); content of decaying wood (Lignomors); and moisture regime (Hydromors, Fibrimors, and Mesimors). Phases can be formed for any taxon to recognize important morphological properties that deviate from the taxonomic differentiae. Keys to the recognized taxa and descriptions of representative humus form profiles for each group are provided to assist in identification. Methods for describing, sampling, and surveying humus forms are presented to facilitate field examinations and subsequent studies.

Keywords: Humus; forest floor; humus form; moder; mor; mull; soil classification

Document Type: Journal Article

Publication date: 1993-02-01

More about this publication?
  • Forest Science is a peer-reviewed journal publishing fundamental and applied research that explores all aspects of natural and social sciences as they apply to the function and management of the forested ecosystems of the world. Topics include silviculture, forest management, biometrics, economics, entomology & pathology, fire & fuels management, forest ecology, genetics & tree improvement, geospatial technologies, harvesting & utilization, landscape ecology, operations research, forest policy, physiology, recreation, social sciences, soils & hydrology, and wildlife management.
    Forest Science is published bimonthly in February, April, June, August, October, and December.

    2015 Impact Factor: 1.702
    Ranking: 16 of 66 in forestry

    Average time from submission to first decision: 62.5 days*
    June 1, 2016 to Feb. 28, 2017

    Also published by SAF:
    Journal of Forestry
    Other SAF Publications
  • Submit a Paper
  • Membership Information
  • Author Guidelines
  • Podcasts
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more