Humusica 2, article 12 : Aqueous humipedons - Tidal and subtidal humus systems and forms
Zanella, A. ; Ferronato, Chiara ; Nobili, Maria De; Vianello, Gilmo ; Vittori Antisari, L. ; Ponge, J.F. ; Waal, R. de; Delft, B. van; Vacca, A. - \ 2018
Applied Soil Ecology 122 (2018)2. - ISSN 0929-1393 - p. 170 - 180.
Soils formed in tidal and subtidal environments often do not show sufficient accumulation of undecomposed plant tissues to be classified as Histosols. In this article we present a first attempt of morpho-functional classification of aquatic humus, a revision of the terminology and of the diagnostic features employed by pedologists in the description of aqueous and submerged soils, and we finally suggest some criteria to be used during field investigations. According to the proposed criteria, Redoxi, Reductitidal, and Subtidal humus forms can be distinguished in aquatic systems, avoiding any possible confusion with Histic, Epihisto, Hydro and Para Anaero/Archaeo or Crusto humus forms. The article concludes with some examples of classification, including prefixes for detailing particular intergrades with the other groups of humipedons and with the discussion of the contribution of algae and seagrasses to the formation of Crusto forms.
Species living in hars environments have low clade rank and are localized on former Laurasian continents: a case study of Willemia (Collembola)
Prinzing, A. ; Haese, C.A. D'; Pavoine, S. ; Ponge, J.F. - \ 2014
Journal of Biogeography 41 (2014)2. - ISSN 0305-0270 - p. 353 - 365.
general-purpose genotype - niche conservatism - phylogenetic perspective - desiccation tolerance - evolutionary dynamics - cretaceous collembola - drought acclimation - diversity gradient - biological traits - extinction
Aim Certain species have few living relatives (i.e. they occupy low clade ranks) and hence they possess high conservation value and scientific interest as unique representatives of ancient lineages. However, we do not know whether particular environments favour the maintenance of low clade ranks or whether the distribution of environments across the globe affects the global distribution of clade ranks and, hence, evolutionary uniqueness. In this study, we tested whether and how harsh environments decrease the clade ranks of the species that inhabit them. Location: Global. Methods We described the phylogeny of the collembolan genus Willemia by a parsimonious method based on 52 morphological characters and estimated the species’ use of harsh environments (polar, high mountain, desert, polluted, waterlogged, saline and acidic) from 248 publications. Results: We found that the use of different types of harsh environments is maintained among close relatives and has similar phylogenetic signals (except for the use of salinity). The use of harsh environments might therefore affect the diversification of lineages. Correcting for the phylogenetic non-independence of species, we found that species using harsh environments have comparatively low clade ranks. We also found that species using harsh environments occur almost exclusively on former Laurasian continents and that, as a statistical consequence, Laurasian species tend to have lower clade ranks. Main conclusions: We suggest that harsh environments maintain low-claderank species by decreasing, simultaneoulsy or successively, extinction and speciation, which may eventually explain the major variation in clade rank across the globe. Keywords Abiotic stress, diversification, habitat, Laurasia, niche conservatism, phylogenetic reconstruction, phylogenetic GLS analysis, phylogenetic principal components, root-skewness test, springtails.
A proposal for including humus forms in the World Reference Base for soil resources (WRB-FAO)
Jabiol, B. ; Zanella, A. ; Ponge, J.F. ; Sarton, G. ; Englisch, M. ; Delft, S.P.J. van; Waal, R.W. de; Claire-Le Bayon, R. - \ 2013
Geoderma 192 (2013). - ISSN 0016-7061 - p. 286 - 294.
earthworm invasion - organic-matter - forest - classification - vegetation - france
The morpho-functional classification of humus forms proposed in a previous issue by Zanella and collaborators for Europe has been extended and modified, without any change in diagnostic horizons, in order to embrace a wide array of humus forms at worldwide level and to complete and make more effective the World Reference Base for Soil Resources. For that purpose 31 Humus Form Reference Groups (HFRGs) and a set of prefix and suffix qualifiers are proposed, following the rules erected for the WRB. An exhaustive classification key, respecting the principles of WRB, is suggested and examples of classification are given for some already well known humus forms.
A European morpho-functional classification of humus forms
Zanella, A. ; Jabiol, B. ; Ponge, J.F. ; Waal, R.W. de; Delft, S.P.J. van - \ 2011
Geoderma 164 (2011)3-4. - ISSN 0016-7061 - p. 138 - 145.
In Europe an abundance of humus taxonomies exists starting with early approaches in the late 19th century. Frequently used in an international context, they do not cover all site conditions in the European area. Although having basic concepts and general lines, the European (and North American, Canadian) classification systems differ in important parameters used for the description and classification of humus forms. These discrepancies result in incongruities, so they require adjustments when exchanging partially compatible soil data, even between nearby countries. In 2003, 26 European specialists in humus forms met in Trento (Italy) and decided to formulate rules of classification based on morphogenetic descriptions and diagnostic horizons, adapted to European ecological conditions. Taking into account old and new European and North American systems of humus forms classification, six main references (Anmoor, Mull, Moder, Mor, Amphi and Tangel) were defined, each of them further divided into more detailed categories. This inventory assigned a strong discriminatory power to the action of soil animals. Both semiterrestrial (anoxic) and terrestrial (aerated) topsoils were classified. Descriptors of diagnostic horizons were conceived in accordance with recent international soil classifications. Assigning an ‘ecological value’ to each main humus form along a gradient from biologically active forms, degrading and incorporating all organic remains, to those characterized by the accumulation of poorly transformed organic matter, this European system of classification avoids a strong hierarchical structure and allows a flexible approach open to additional ecological contributions and renditions. --------------------------------------------------------------------------------
European Humus Forms Reference Base
Zanella, A. ; Jabiol, B. ; Ponge, J.F. ; Sartori, G. ; Waal, R.W. de; Delft, S.P.J. van; Kemmers, R.H. - \ 2011