Pedodiversity

In Chap. 6, dealing with pedodiversity of Italy, Edoardo A. C. Costantini, RobertoBarbetti, Maria Fantappie` , Giovanni L’Abate, Romina Lorenzetti, and Simona Maginiillustrate the distribution of soil classes, mainly by means of maps. Soil regions on hillsare the most lithologically and climatically variable environments, and host the greatestsoil variability and endemisms. A vast majority of the WRB reference soil groups (25 outof 32), as well as soil orders of Soil Taxonomy (10 out of 12) are represented in the mainItalian soil typological units (STUs), but the clear skewness and lognormal distributionof STUs demonstrate the utmost endemic nature of many Italian soils. In particular,more than a fourth of STUs belong to Cambisols, more than a half to only fourreference soil groups (Cambisols, Luvisols, Regosols, Phaeozems), and 88 % to nineRSGs (the former plus Calcisols, Vertisols, Fluvisols, Leptosols, and Andosols), whilethe remaining 16 RSGs are represented in 12 % of STUs. A similar trend is depicted byconsidering single soil profile classification, although a larger number of main soil typesare represented as soil profiles than as STUs. In particular, there are profiles classified asAlbeluvisol, Anthrosol, Cryosol, Plinthosol, and Technosol of WRB, and Gelisols ofSoil Taxonomy, which are not correlated to a STU. Consequently, Ferralsols (Oxisolsfor Soil Taxonomy) and Durisols are the only main kind of soils that have not yet beenfound in Italy. Likewise RSGs, the distribution of WRB qualifiers shows an evidentconcentration in relatively few cases, followed by a long tail. In particular, 138 out of the180 types foreseen by WRB are represented in Italy. Thus, it is possible to say that inItaly there is about three-quarters of the global pedodiversity. Although the mostcommon qualifiers (that is Calcaric, Haplic, Skeletic, Eutric) are all related to the natureof parent material and to incipient pedogenesis, a second group (namely Chromic,Calcic, Stagnic, and Luvic) indicates the main soil forming mechanisms that typifycurrent Italian pedogenesis.