Human-Altered and Human-Transported Soils in an Italian Industrial District

Abstract

In many Mediterranean regions industrial activities have drastically affected soil evolution. As a case study, reference is made to an important Chemical Industrial District of southern Italy (Sardinia). Its setting up and development resulted in the formation of human-altered and human-transported (HAHT) soils, largely through physical-mechanical excavation, transportation and rolling out the original soils (Palexeralfs, Haploxeralfs), as well as mixing and covering them with innocuous artifacts referred to as human-transported materials (HTM). On this basis, research began with a view to evaluating the anthropogenic processes in addition to the main morphological and physical-chemical characteristics of HAHT soils as compared with reference soils (RefS), their pedovariability and the classification of HAHT soils through Soil Taxonomy. The anthro-pedoturbation induced by mixing HTM to preexisting-presently buried-soils has dramatically disturbed the "natural" pedogenetic evolution, and driven the pro-isotropic processes leading the HAHT soils to much more simplified morphology and homogenization of chemical-physical features, with an impressive loss of pedovariability. They currently meet the requirements for a "mantle" classifiable as Alfic Xerarents, as an expression of the "entisolization" that induced a taxonomic shift from Alfisols to anthropogenic Entisols

Through the Decades: Taxonomic Proposals for Human-Altered and Human-Transported Soil Classification

“…Spolic materials contain less than 3% by volume recognizable fragments of diagnostic soil horizons arranged in discernible order (ICOMANTH, 2003), and, as such, this term would appear to be unsuitable for the investigated HAHT soils, which are instead characterized by the presence of more than 3% of fragments of the argillic horizon once present in the former Alfisols (Table 2). Considering the xeric moisture regime of the investigated soils (Capra et al, 2012), such pedons can perhaps be classified as Xerants ( Xer‐ants ). In these terms, another possible proposal may be acceptable according to the U.S.…”

“…However, ICOMANTH has specified that this term is to be used for human‐altered material for subgroups of Entisols (formerly Arents) where deep plowing has destroyed former diagnostic horizons (argillic in the investigated HAHT soils). In actual fact, for the investigated HAHT soils (Table 2), the diagnostic argillic horizon was destroyed by the physical–mechanical excavation, transportation, and rolling out of the original Alfisols (Capra et al, 2012). From this point of view, the term Anthroportic perhaps better describes the situation for the investigated HAHT soils, as they are used for HTM of dredged or mine spoil soil series that had formerly been Arents, but which could be used for any human‐transported material (Galbraith, 2012b).…”

“…In this study, as explained previously, reference was made to HAHT soils recently investigated by Capra et al (2012). As a practical example, the main morphological and physical–chemical characteristics of one representative (OTT3) pedotype were reported (Table 2).…”

“…As a practical example, the main morphological and physical–chemical characteristics of one representative (OTT3) pedotype were reported (Table 2). Very briefly, all the five investigated HAHT pedons (Capra et al, 2012) were classified (order level) by checking the mantle features, but using the buried soil characteristics at the suborder or lower levels (Galbraith, 2011; Soil Survey Staff, 1999). From this point of view, all the investigated HAHT pedons were classified (Soil Survey Staff, 2010) as Alfic Xerarents (Fig.…”

“…As a practical example, the main morphological and physicalchemical characteristics of one representative (OTT3) pedotype were reported (Table 2). Very briefl y, all the fi ve investigated HAHT pedons (Capra et al, 2012) were classifi ed (order level) by checking the mantle features, but using the buried soil characteristics at the suborder or lower levels (Galbraith, 2011;Soil (Si): fi ne = 0,2-5 cm, medium = 5-10 cm, coarse = 10-25 cm. ‡ Amount (Am); Type (Ty): br = bricks, cb = cinder blocks, co = concrete (ICOMANTH, 2005); Size (Si): fi ne = 0.2-2 cm, medium = 2-7.5 cm, coarse = 7.5-25 cm (ICOMANTH, 2005).…”