8.02.03 - Humus and soil biodiversity


Michael Englisch, Austria

About Unit

A network of European humus researchers was founded in Trento (Italy) in 2003, gathering 26 specialists from eight European countries. Since then, the group, meanwhile a Unit within the framework of IUFRO and joined by new participants, meets every year in different countries in order to exchange knowledge, discover humus forms in new ecological conditions and making progress in harmonizing humus classification concepts.

State of Knowledge

In 1993 and 1994 – almost simultaneously – two important humus form classifications were published: one in France (Jabiol et al. 1994), developed from a long European tradition of research on humus (Babel, Delecour, Duchaufour, Kubiena, Hartmann); the other in Canada (British Columbia – Green et al. 1993), re-examining the first approximation made by Klinka et al. 1981.

However, neither of these proposals is fully applicable on a European scale, since both of them have been elaborated in a limited climatic context:

  • The classification of Green et al. correspond to the climate conditions of the pacific North-West and is inadequate for active humus forms (MULLs);
  • The French classification has some lacks in describing adequately the less active humus forms that are present in northern Europe.
  • None of these two classifications is fully applicable to describe Mediterranean or mountain humus forms.

Since then, in Europe, several working groups tested these classifications, trying – often – to compare these two methods (Calabrese et al. 1997, Zanella et al. 2001).

For this reason, it was thought important to gather some European experts, in order to:

  • Pool knowledge and current projects on humus forms in different European regions (latitude, longitude, and variable altitude);
  • list all issues that need further research to get an overall understanding of humus forms;
  • get to an international research level, which would be useful to find further financing;
  • suggest, a internationally accepted classification, on European scale, able to become a working group in World Reference Base of soils.


Calabrese, M. S., Sartori, G., & Zanella, A. (1997). Confronto tra due recenti sistemi di classificazione degli humus : il Référentiel Pédologique e la tassonomia di Green. Monti e Boschi, 6, 4–10. https://www.research.unipd.it/handle/11577/118400 (ISSN: 1124-1454)

Green, R. N., Trowbridge, R. L., & Klinka, K. (1993). Towards a taxonomic classification of humus forms. Forest Science Monographs, 29, 1–49.

Jabiol, B., Brêthes, A., Brun, J.-J., Ponge, J. F., & Toutain, F. (1994). Une clasification morphologique et fonctionnelle des formes d’humus. Proposition du Référentiel Pédologique 1992. Rev. For . Fr., 46(2), 152–156. https://doi.org/10.4267/2042/26527

Klinka, K., Green, R. N., Trowbridge R.L., & L.E., L. (1981). Taxonomic classification of humus forms in ecosystems of British Columbia. First approximation. In Land and Management (Report 8). Ministry of Forests. http://agris.fao.org/agris-search/search.do?recordID=CA19830870495

Zanella, A., Tomasi, M., Cesare, D. S., Frizzera, L., Jabiol, B., Nicolini, G., Sartori, G., Calabrese, M. S., Manacabelli, A., Nardi, S., Pizzeghello, D., & Maurizio, O. (2001). Humus Forestali - Manuale di ecologia per il riconoscimento e l’interpretazione - Applicazione alle faggete (A. Zanella, M. Tomasi, C. De Siena, L. Frizzera, B. Jabiol, & G. Nicolini (eds.); CEA). Centro Ecologia Alpina, Fondazione Edmund Mach. http://www.fmach.it/Servizi-Generali/Editoria/Humus-forestali-manuale-di-ecologia-per-il-riconoscimento-e-l-interpretazione-applicazione-alle-faggete