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    An index of divergence from species to life-form diversity

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    In this paper, we propose a measure of divergence from species to life-form diversity based on the notion of intrinsic diversity ordering. First, species and life-form relative abundances within the analyzed community are determined. Next, community intrinsic diversity profile is computed both from species and life-form relative abundances. Finally, the speed of decrease from species to life-form diversity is obtained by comparing the area under the species diversity profile with the area under the corresponding life-form diversity profile. Since life-forms classify plants into ecologically relevant groups irrespective of their systematics, the proposed measure might be useful to quantify the ecological similarity of different communities without loosing information on traditional taxonomic diversity figures. As an application for demonstration, a small data set from a garigue community on ultramafic soils of Tuscany (central Italy) is used

    Quantifying the effects of nutrient addition on the taxonomic distinctness of serpentine vegetation

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    Traditional diversity indices summarize the information about the relative abundances of species within a community without regard to differences between species. However, intuitively, a community composed of dissimilar taxa is more diverse than a community composed of more similar taxa. Therefore, useful indices of diversity should account for taxonomic relations among species. In this paper, a new parametric diversity index that combines species relative abundances and their taxonomic distinctiveness is used to quantify the way in which soil fertilization affects the diversity of a garigue community on ultramafic soils of Tuscany (central Italy). Results show that, while ultramafic soils generally host plant communities of limited taxonomic diversity with respect to similar communities on other substrates, fertilization significantly enhances the biomass production of species that are not exclusive to ultramafic soils. As a consequence, if diversity is measured combining species relative abundances with their taxonomic distinctiveness, nutrient addition tends to increase the diversity of ultramafic communities

    Un'analisi statistica del turismo sostenibile in Calabria

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    Le ragioni che hanno ispirato la stesura del presente lavoro sono quelle di individuare alcuni indicatori riguardanti il turismo sostenibile. Per calcolare gli indicatori sulla consistenza ricettiva ed i flussi turistici sono stati utilizzati i dati del 2009 forniti dal SITRC (Sistema Informativo Turistico Regione Calabria). Mentre quelli sullo smaltimento dei RU e la raccolta differenziata, sono relativi al 2006, forniti dall’Ufficio del Commissario delegato per l’emergenza rifiuti della regione calabrese. L’obiettivo è di analizzare la sostenibilità del turismo per le cinque province calabresi. L’analisi statistica è stata condotta sulla base di tre gruppi di indicatori: indicatori della domanda turistica, indicatori dell’offerta turistica e indicatori dell’impatto ambientale del settore turistico. Successivamente è stato calcolato e analizzato per le cinque province calabresi un «indicatore composto Gi», derivante dalla media di tutti gli indici presi in esame. Infine ci si è proposti di evidenziare l’esistenza di un dualismo fra aree ancora poco sfruttate (nonostante la forte vocazione turistica) e aree ai limiti della saturazione
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