title: Soil and plant changing after invasion: the case of Acacia dealbata in a Mediterranean ecosystem.
abstract: Acacia dealbata Link (Fabaceae) is one of the most invasive species in the Mediterranean ecosystems of Europe, Africa and America, where it has been proved to exert strong effects on soil and plant communities. In Italy A. dealbata has been largely used for ornamental and forestry purpose and is nowadays spreading in several areas. The present study was addressed to evaluate the impacts on soil chemical properties, soil microbial communities and understory plant communities and to assess the relationships among these compartments after the invasion of A. dealbata in a typical Mediterranean shrubland. Towards these aims, a soil and vegetation sampling was performed in Elba Island where A. dealbata is invading the sclerophyllous native vegetation. Three levels of invasion status were differentiated according to the gradient from invaded, to transitional and non-invaded vegetation. Quantitative and qualitative alterations of soil chemical properties and microbial communities (i.e. bacterial and fungal communities) and above-ground understory plant communities were found. In particular, the invaded soils had lower pH values than both the non-invaded and transitional ones. High differences were detected for both the total N and the inorganic fraction (NH4(+) and NO3(-)) contents, which showed the ranking: invaded>transitional>non-invaded soils. TOC and C/N ratio showed respectively higher and lower values in invaded than in non-invaded soils. Total plant covers, species richness and diversity in both the non-invaded and transitional subplots were higher than those in the invaded ones. The contribution of the nitrophilous species was significantly different among the three invasion statuses, with a strong increase going from native to transitional and invaded subplots. All these data confirm that A. dealbata modifies several compartments of the invaded ecosystems, from soil chemical properties to soil and plant microbial communities determining strong changes in the local ecosystem processes.
authors.affiliation: Department of Biology, University of Florence, via G. La Pira 4, I-50121 Florence, Italy. Electronic address: lorenzo.lazzaro@unifi.it.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Lazzaro
authors.affiliation: Department of Biology, University of Florence, via G. La Pira 4, I-50121 Florence, Italy. Electronic address: claudia.giuliani@unifi.it.
authors.forename: Claudia
authors.initials: C
authors.lastname: Giuliani
authors.affiliation: Consiglio per la Ricerca e sperimentazione in Agricoltura, Centro di ricerca per l'Agrobiologia e la Pedologia, CRA-ABP, Piazza D'Azeglio 30, 50121 Florence, Italy. Electronic address: arturo.fabiani@entecra.it.
authors.forename: Arturo
authors.initials: A
authors.lastname: Fabiani
authors.affiliation: Consiglio per la Ricerca e sperimentazione in Agricoltura, Centro di ricerca per l'Agrobiologia e la Pedologia, CRA-ABP, Piazza D'Azeglio 30, 50121 Florence, Italy. Electronic address: alessandroelio.agnelli@entecra.it.
authors.forename: Alessandro Elio
authors.initials: AE
authors.lastname: Agnelli
authors.affiliation: Consiglio per la Ricerca e sperimentazione in Agricoltura, Centro di ricerca per l'Agrobiologia e la Pedologia, CRA-ABP, Piazza D'Azeglio 30, 50121 Florence, Italy. Electronic address: roberta.pastorelli@entecra.it.
authors.forename: Roberta
authors.initials: R
authors.lastname: Pastorelli
authors.affiliation: Consiglio per la Ricerca e sperimentazione in Agricoltura, Centro di ricerca per l'Agrobiologia e la Pedologia, CRA-ABP, Piazza D'Azeglio 30, 50121 Florence, Italy. Electronic address: alessandra.lagomarsino@entecra.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Lagomarsino
authors.affiliation: Department of Biology, University of Florence, via G. La Pira 4, I-50121 Florence, Italy. Electronic address: renato.benesperi@unifi.it.
authors.forename: Renato
authors.initials: R
authors.lastname: Benesperi
authors.affiliation: Department of Biology, University of Florence, via G. La Pira 4, I-50121 Florence, Italy. Electronic address: roberto.calamassi@unifi.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Calamassi
authors.affiliation: Department of Biology, University of Florence, via G. La Pira 4, I-50121 Florence, Italy. Electronic address: bruno.foggi@unifi.it.
authors.forename: Bruno
authors.initials: B
authors.lastname: Foggi
mesh_terms: D000045:Acacia; D000349:Africa; D058865:Introduced Species; D007558:Italy; D019083:Mediterranean Region; D012987:Soil; D012988:Soil Microbiology
chemical_list: D012987:Soil
keywords: Ecosystem impacts; Invasion; Soil chemistry; Soil microbiota; Understory plants