Applied Soil Ecology 46 (2010) 1–8 Contents lists available at ScienceDirect Applied Soil Ecology journal homepage: www.elsevier.com/locate/apsoil Rehabilitation of Mediterranean anthropogenic soils using symbiotic wild legume shrubs: Plant establishment and impact on the soil bacterial community structure Massimiliano Cardinale a,1 , Lorenzo Brusetti b,2 , Angela Lanza a , Salvatore Orlando a , Daniele Daffonchio b , Anna Maria Puglia a , Paola Quatrini a,∗ a Università degli Studi di Palermo, Dipartimento di Biologia Cellulare e dello Sviluppo, Viale delle Scienze, 90128 Palermo, Italy b Università degli Studi di Milano, Dipartimento di Scienze e Tecnologie Alimentari e Microbiologiche, Via Celoria 2, 20133 Milano, Italy article info Article history: Received 26 August 2009 Received in revised form 14 May 2010 Accepted 18 May 2010 Keywords: Anthropogenic soil rehabilitation Mediterranean legume shrubs Rhizobia Arbuscular mycorrhizal fungi Soil bacterial communities ARISA abstract Susceptibility to desertification in southern Europe is increasing and rehabilitation of desertification- threatened Mediterranean soils is a challenge due to the inhospitality of the environment. In particular, recovery of anthropogenic soils (mainly human-derived artefacts from housing construction and other inert materials or topsoil of terminal phase municipal landfills) cannot rely on spontaneous processes and low-cost/low-impact strategies are needed to prevent desertification. Mediterranean wild legume shrubs have great potential for soil recovery and conservation against desertification, thanks to drought resistance, and their symbiosis with N 2 -fixing rhizobia and arbuscular mycorrhizal fungi. In this study double inoculated autochthonous wild legume shrubs (the genistea Spartium junceum L. and the ther- mopsidea Anagyris foetida L.) were used in a long-term trial to recover an anthropogenic hill in a semi-arid site of southern Italy, mainly composed of inert and human-derived artefacts. Microbial inoculants strongly enhanced plant establishment and growth on the anthropogenic soil in the greenhouse and in the field up to two years. Automated Ribosomal Intergenic Spacer Analysis (ARISA) and bacterial cultivation revealed a dramatic effect of the tripartite symbiosis on the structure of soil bacterial communities that largely overcomes plant species effect and suggests synergism of AMF with the bacterial community of the mycorhizosphere. Our results demonstrate that microsymbiont inoculation on wild legume shrubs is a promising strategy to rehabilitate anthropogenic soils in Mediterranean semi- arid regions. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Soil susceptibility to desertification in southern Mediterranean regions is increasing (Diffenbaugh et al., 2007), due to a lower water contribution, increasing salinity and soil erosion. Other important factors are human activities such as intensive soil exploitation, unsustainable agro-pastoral practices, mining and the multiplica- tion of municipal landfills on the territory. Anthropogenic soils are characterised by a strong influence of human activities and are one of the main concerns of modern pedol- ogy due to the increasing number of sites affected by anthropogenic ∗ Corresponding author at: Dipartimento di Biologia Cellulare e dello Sviluppo Edificio 16, Viale delle Scienze, 90128 Palermo, Italy. Tel.: +39 091 23897320; fax: +39 091 6577347. E-mail address: quatrini@unipa.it (P. Quatrini). 1 Present address: Graz University of Technology, Institute of Environmental Biotechnology, Petersgasse 12, A-8010 Graz, Austria. 2 Present address: Free University of Bozen/Bolzano, Faculty of Science and Tech- nology, Via Sernesi 1, 39100 Bolzano/Bozen, Italy. activities and to their impact on human health, environment and landscape (FAO, 2006). Most of these soils are composed by materials and pollutants deposited by humans in various “earth- moving” operations such as surface mining, deposition of dredging spoils, additions of earthy fill materials or human-derived artefacts obtained during housing and highway construction. These materi- als alter rapidly and dramatically both the direction and extent of soil forming processes, affecting the soil characteristics and func- tions (structure, pH, aeration, water drainage, nutrients cycling and temperature regimes) (Lehmann and Stahr, 2007). Anthropogenic soils are characterized by great heterogeneity, extreme values of bulk density (from less than 0.5 to more than 1.6 kg dm -3 ), coarse textures, high water permeability, generally high pH (when arte- facts are construction residues), low nutrient levels (depending on the parent material) and contamination with inorganic and organic contaminants. In extreme cases (e.g. mining, disposal areas) it has been suggested that they could not be considered as soils in either a pedological or a biological sense (Séré et al., 2008). Restoration of anthropogenic soils, however, is needed for protection of human health (Lehmann and Stahr, 2007) and to increase the soil carbon 0929-1393/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.apsoil.2010.05.007