177 research outputs found

    First record of Sphaeralcea bonariensis (Cav.) Griseb. (Malvaceae) as a casual alien species in the Mediterranean area

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    Sphaeralcea bonariensis (Cav.) Griseb. is here reported for the first time as alien species in Italy and in the Mediterranean area. It is a perennial shrub native to Southern America, where it is often considered a ruderal species frequent in cultivated areas. It was found in a population of a few individuals within Opuntia ficus-indica groves of Rocca Palumba territory (Western Sicily). Actually, due to short-term observational period and the low number of plants, Sphaeralcea bonariensis should be considered as a casual species in Italy. The ecological characteristics of the growing stand and the consistency of the population, as well as the possible causes of its introduction, are briefly discussed

    The endemic vascular flora of Peloritani Mountains (NE Sicily): Plant functional traits and phytogeographical relationships in the most isolated and fragmentary micro-plate of the Alpine orogeny

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    This study is aimed at (1) producing a complete and updated inventory of the endemic vascular flora of Peloritani Mountains, (2) defining the geographical limits of Peloritani, regarded here as a biogeographical district and (3) highlighting possible paleogeographic connections with other Mediterranean lands. The heterogeneity analysis of the endemic flora was performed by means of contingency tables, through the x 2 test. The endemic flora of this area consists of 129 specific and infraspecific taxa, of which 15 are restricted to the Peloritani Mountains. The analysis of habitats revealed that endemic taxa are most abundant on cliffs, rangelands, woods and garrigues. A large number of surveyed taxa are endemic to central-southern Italy and Sicily, while the number of endemic taxa in common with Calabria, Etna and Aeolian Islands turned out to be rather low, in spite of the geographical proximity. The endemic flora of Peloritani allows to emphasize palaeogeographical relationships not only with the neighbouring Mediterranean territories, but also with currently remote ones, such as southern Spain, Sardinia and Corsica. The phytogeographical framework substantiates the hypothesis that the Peloritani floristic district coincides with the limit given to Peloritani Mountains by structural geologists

    The alien vascular flora of the Pantelleria Island National Park (Sicily Channel, Italy): new insights into the distribution of some potentially invasive species

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    Pantelleria is a volcanic island located in the Sicily Channel (Italy), between Sicily and Tunisia. The island, designated a National Park in 2016, hosts an interesting vascular flora of over 600 species including 9 narrow endemics. The island’s incredible biodiversity is, however, at risk due to anthropogenic influences, climate change, and, recently, the presence and spread of alien plant species. The Pantelleria alien flora has never been thoroughly investigated, probably because many non-native species were not yet present or so widespread on the island. Now, however, with the increased general awareness of the risks associated with invasive alien species, documentation of the presence of non-native species has been steadily increasing. In this study, field and literature research was carried out to investigate the alien flora of the island. Here, we report the status of a number of non-native plants with known invasive potential. Cenchrus setaceus (=Pennisetum setaceum) is reported for the first time as naturalized in the island with clear invasive behaviour, while, particularly remarkable for their invasive potential are other studied plants such as: Acacia saligna, Ailanthus altissima, Boheravia coccinea, Carpobrotus edulis, Leucaena leucocephala subsp. glabrata, Malephora crocea, Melia azedarach, Nicotiana glauca, Opuntia ficus-indica, Parkinsonia aculeata, Washingtonia robusta and a few others less important at the moment, but to be monitored. Although most taxa showed a relatively limited distribution, the trend is to observe an increased invasiveness, which indicates that they can potentially become invasive in Pantelleria as well in the next years or decades. Their limited current distribution suggests that these species are in the early stages of the general invasion curve, when intervention is feasible and most likely to succeed. Therefore, it is most prudent to prioritize management for as many potentially problematic nonnatives as possible, which will contribute greatly to the conservation of native species and ecosystems of Pantelleria. Prevention and management of invasive non-native species—both future arrivals and those already present—are necessary to preserve the peculiar volcanic landscape of Pantelleria, which was shaped by man over the last millennia

    Floristic and vegetation changes on a small mediterranean island over the last century

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    A synthetic and updated overview about the vascular flora and vegetation of the Island of Capo Passero (SE‐Sicily) is provided. These data issue from two series of field surveys—the first carried out between 1997 and 2000, and the second between 2005 and 2019 and mostly focused on refining and implementing vegetation data. The current islet’s flora consists of 269 taxa, of which 149 (58%) are annual plants. The Mediterranean species are largely prevailing, 108 (40%) of which have a strictly Mediterranean biogeographical status. The comparison with a species list published in 1919 and updated in 1957 suggest that, despite the overall prevalence of anemochorous taxa, the vertebrate fauna represents an important vector for the plant colonization of the island, while the immigration of myrmechocorous taxa does not compensate the extinction rate. As many as 202 phy-tosociological relevés, 191 of which issue from original recent field surveys, enabled identifying 12 different plant communities. The comparison with a vegetation map published in 1965 suggests a strong reduction in dune habitats (2120 and 2210 according to EU ‘Habitats’ Directive 92/43), as well as a deep disruption in the succession typical of the local psammophilous vegetation series. In order to preserve rare, endangered and protected plant species (such as Aeluropus lagopoides, Cichorium spinosum, Limonium hyblaeum, L. syracusanum, Poterium spinosum, Senecio pygmaeus and Spergularia heldreichii) and to stop the ongoing habitat degradation, urgent and effective conservation measures should be adopted for this tiny, yet precious islet

    Analysis of Juniperus phoenicea from throughout its range in the Mediterranean using DNA sequence data from nrDNA and petN-psbM: the case for the recognition of J. turbinata Guss

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    DNA sequences were analyzed from 19 populations of J. phoenicea from throughout its range. The sequence data (nrDNA, petN-psbM) revealed that J. phoenicea is clearly divided into two taxa. These taxa have been recognized as var. (subsp.) phoenicea and var. (subsp.) turbinata by Adams (2011) and Farjon (2005). However, the magnitude of the differences in the DNA regions, along with the differences in pollen shedding times, morphology and prodelphinidin content support the recognition of J. turbinata Guss. No differentiation was found between the typical Mediterranean and Canary Island populations, offering no support for the recognition of J. phoenicea subsp. canariensis (Guyot) RivasMartinez. Juniperus turbinata appears to be widespread from Madeira - Canary Islands to the Sinai with few DNA differences among most populations. However, some populations (Grazalema, Madeira, Sinai, central Italy) had moderate amounts of divergence (3-4 mutations) and warrant additional study

    Acetaldehyde binding energies: a coupled experimental and theoretical study

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    Acetaldehyde is one of the most common and abundant gaseous interstellar complex organic molecules, found in cold and hot regions of the molecular interstellar medium. Its presence in the gas-phase depends on the chemical formation and destruction routes, and its binding energy (BE) governs whether acetaldehyde remains frozen onto the interstellar dust grains or not. In this work, we report a combined study of the acetaldehyde BE obtained via laboratory TPD (Temperature Programmed Desorption) experiments and theoretical quantum chemical computations. BEs have been measured and computed as a pure acetaldehyde ice and as mixed with both polycrystalline and amorphous water ice. Both calculations and experiments found a BE distribution on amorphous solid water that covers the 4000--6000 K range, when a pre-exponential factor of 1.1×1018s11.1\times 10^{18}s^{-1} is used for the interpretation of the experiments. We discuss in detail the importance of using a consistent couple of BE and pre-exponential factor values when comparing experiments and computations, as well as when introducing them in astrochemical models. Based on the comparison of the acetaldehyde BEs measured and computed in the present work with those of other species, we predict that acetaldehyde is less volatile than formaldehyde, but much more than water, methanol, ethanol, and formamide. We discuss the astrochemical implications of our findings and how recent astronomical high spatial resolution observations show a chemical differentiation involving acetaldehyde, which can easily explained as due to the different BEs of the observed molecules.Comment: 12 pages, 6 figure

    Alnus glutinosa Riparian Woodlands of Italy and Corsica: Phytosociological Classification and Floristic Diversity

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    A comparative analysis of the riparian vegetation dominated by Alnus glutinosa in Italy and Tyrrhenian islands, based on literature data and unpublished releves, is presented. A total of 456 phytosociological releves were processed. For the definition of plant communities and alliances, hierarchical clustering was performed by using Bray-Curtis coefficient and Detrended Correspondence Analysis ordination methods. Identification of diagnostic species of the vegetation units was performed by means of the phi fidelity index. Quantum GIS software version 3.6 was used for the interpolation of the bioclimatic variables and A. glutinosa communities. Overall, a total of 18 A. glutinosa-riparian wood communities were distinguished for Italy and Tyrrhenian islands, of which two new associations and one new subassassociation are described. The classification of the releves showed two main vegetation groups: the first one including the plant communities of the Osmundo-Alnion alliance, and the other including the vegetation of the Ligustro vulgaris-Alnion glutinosae alliance. This latest includes the riparian meso-thermophilous communities of central and northern Italy. Within the Osmundo-Alnion alliance, two subgroups can be recognized: the first one includes the thermophilous communities of the Hyperico hircini-Alnenion glutinosae sub-alliance, mainly spread in the Tyrrhenian islands, while the second group includes the mesophilous communities attributed to the new suballiance Struthioptero-Alnenion glutinosae, widespread in central Italy and the Corsican mountains. The present paper provides the first comprehensive and exhaustive scheme of the A. glutinosa riparian woodlands diversity in Italy and Corsica
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