200 research outputs found

    The lower pleistocene succession

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    ItVengono esposti aspetti stratigrafici e paleontologici di una successione calcarenitico-sabbioso-argillosa spessa 4,1 m, affiorante in Contrada Torsano (Nardò, provincia di Lecce), caratterizzata da livelli fossiliferi a molluschi, scafopodi, brachiopodi e coralli tra cui prevalgono Venus verrucosa, V. casina, Acanthocardia tuberculata, Aequipecten opercularis, Glossus humanus, Thracia convexa, Neopycnodonte cochlear, Pecten jacobaeus, Terebratula scillae, Dentalium rectum e Flabellum sp.; sono altresì presenti gli "ospiti nordici" Pseudamussium septemradiatum, Paphia rhomboides e soprattuto Arctica islandica. Quest’ultima è rappresentata da individui di grande taglia analogamente a popolamenti nordatlantici attuali (KENNISH and LUTZ, 1995; THORARINSDOTTIR and EINARSSON, 1996). I livelli fossiliferi (shell concentrations sensu KIDWELL, 1991; FÜRSICH, 1995) hanno caratteri di deposito primario e possono rappresentare il prodotto di strategie di adattamento o di favorevoli condizioni ecologiche.La maggior parte delle specie riconosciute nella successione di Torsano è attualmente presente nel Mediterraneo (PARENZAN, 1970; 1974; 1976; DEMIR, 2003; REPETTO et al., 2005). Alcune sono indicative di particolari condizioni ambientali come Lucinoma boreale, tipica di fondali mobili (MALATESTA, 1974) e Thracia convexa, esclusiva delle Biocenosi dei fanghi Terrigeni Costieri (PICARD, 1965; PÉRÈS, 1967).In generale, dalla base al tetto della successione analizzata, è definibile un cambiamento delle condizioni paleoambientali dalla zona infralitorale, soggetta a fenomeni di abrasione meccanica delle onde, a quella circalitorale per progressivi aumenti delle profondità del fondale e della torbidità delle acque.EnThis paper deals with the stratigraphic and paleontological features of a 4.1 m thick succession outcropping at Contrada Torsano (Nardò, Lecce province). Shell concentration due to biological processes, particularly rich in the northern guests Arctica islandica, Pseudamussium septemradiatum and Paphia rhomboides are described. Based on Terebratula scillae and Dentalium rectum presences, the succession must be attributed to the lower Pleistocene. The high specimen density could be due to opportunistic life strategies and optimal ecological conditions. Environmental change can be recognized from the infralittoral zone, exposed to the marine abrasion, to circalittoral zone as the result of the increasing of both depth and sea water turbidity

    IUCN red list evaluation of the orchidaceae endemic to apulia (Italy) and considerations on the application of the IUCN protocol to rare species

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    The conservation status of the ten taxonomically currently recognised orchid species and subspecies (eight in the genus Ophrys, and one each in the genera Epipactis and Serapias) endemic to Apulia (southeast Italy) is presented. Each taxon has been assessed against the internationally accepted IUCN criteria and categories. Of the ten taxa, eight ones are classified as threatened (Endangered or Vulnerable), one as Near Threatened and one as Least Concern. Given that nine of the ten analysed taxa were recently assessed, a comparison with the previous assessments is presented: 67% of the assessed taxa changed their IUCN category. Four taxa (Ophrys murgiana, O. oxyrrhynchos subsp. ingrassiae, O. peucetiae, O. tardans) are now assigned to a higher threat category, while two taxa (Ophrys gravinensis and O. oestrifera subsp. montis-gargani) are now assigned to a lower threat category. These category changes in such a very short time are due to the better knowledge on the number of mature individuals and on the threats affecting the species, and to the discovery of new occurring sites. The most important category change affects Ophrys tardans. The new assessment leads to the category Endangered, whereas in the previous assessment this species was indicated as Least Concern, i.e. as not threatened. Another species with a noteworthy category increase is Ophrys peucetiae, previously indicated as Least Concern and now assigned to the category Vulnerable. The authors discuss these results, highlighting that especially when assessing rare species with a small distribution range against the IUCN protocol, it should be taken into account that the assessment could be influenced (also noteworthy) by the effective knowledge on the distribution, on the population size and on the threats affecting the populations. As a consequence, field work is warmly suggested before assessing the threat category of rare taxa, given that an increased effort in field research often leads to the discovery of new sites and to a better estimation of the number of individuals and of the threats

    Contributo alla conoscenza floristica dei licheni italiani: Florula Lichenica del tratto costiero adriatico salentino Torre Rinalda - Le Cesine (Le)

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    EnIn this work the first results of a lichenological survey in the coastal area between Torre Rinalda and "Le Cesine" (Lecce-South Italy) are eported. Altogether in this area 74 species have been listed, prevalently temperate-mediterranean taxa. The presence of genus Parmotrema (P. chinense, P. hypoleucinum, P. eticulatum) shows that this taxon is not confined along the Tyrrenian coast, where it is common.Particularly, P. hypoleucinum is very abundant and luxuriant in the sheltered area "Le Cesine", a humid zone of international importance, maybe owing to the microclimatic conditions (high humidity, chill Balkan winds)

    Contributo alla conoscenza floristica dei licheni italiani: Florula lichenica della costa di Nardò e Porto Cesareo-LE

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    EnHere is a report about the results of a lichenological survey in the coastal area between Torre Inserraglio and Punta Prosciutto (Lecce-South-East Italy). Altogether in this area 46 species have been found on three substrata: a) rock; b) soil; c) bark. Though the research considers only a part of taxa presents inside the area, it shows some important data: - Prevalence of crusty lichens, mostly on rocky substratum; - Absence of sub-oceanic species like Parmotrema hypoleucinum (Steiner) Hale, which is present along Salentine Adriatic coast; - High lichenic biodiversity of "Palude del Capitano", "Spunnulate di T.rre Castiglione", "macchie di Arneo"

    Comparative chromosome studies in species of subtribe Orchidinae (Orchidaceae)

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    In our study, FISH mapping using 18S-5.8S-25S rDNA and 5S rDNA sequences was performed for the first time on Ophrys tenthredinifera Willdenow, 1805, Serapias vomeracea (Burman f., 1770) Briquet, 1910 and Himantoglossum hircinum (Linnaeus, 1753) Sprengel, 1826. A detailed study was also performed on O. tenthredinifera using Giemsa-staining, silver-staining, CMA fluorescence banding and fluorescence in situ hybridisation (FISH) with rDNA probes. We analysed two subspecies, i.e. O. tenthredinifera subsp. neglecta (Parlatore, 1860) E.G. Camus, 1908 and O. tenthredinifera subsp. grandiflora (Tenore, 1819) Kreutz, 2004 by the traditional Feulgen method and constructed the karyotype. The cytotaxonomic implications for both taxa are also discussed. In Himantoglossum hircinum, FISH and silver staining highlighted differences in the number of two rDNA families (35S and 5S) with respect to Barlia robertiana (Loiseleur-Deslongchamps, 1807) Greuter, 1967. In addition, fluorescence in situ hybridisation was also applied to diploid (2n = 2x = 36) and triploid (2n = 3x = 54) Anacamptis morio (Linnaeus, 1753) R.M. Bateman, Pridgeon et M.W. Chase, 1997. As far as we are aware, this is the first case of autotriploidy observed in A. morio

    Methyl Hexadecyl Viologen Inclusion in Cucurbit[8]uril: Coexistence of Three Host-Guest Complexes with Different Stoichiometry in a Highly Hydrated Crystal

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    The host-guest inclusion complexes of cucurbiturils with alkyl viologen have interesting architectures, chemical properties, and potential applications in sensors and nanotechnology. A highly hydrated triclinic crystal of cucurbit[8]uril (CB[8]) complexed by methyl hexadecyl viologen (MVC16) is characterized by the unprecedented coexistence in the crystal of three host-guest complexes with 3:2, 2:2, and 1:1 stoichiometries. In all these complexes, the hook-shaped alkyl chain of the MVC16 is hosted in the CB[8] macrocycles, while the methyl viologen moieties have various environments. In the Z-shaped 3:2 complex, a central CB[8] unit hosts two viologen heads in the cavity, while the 2:2 complex is held together by \u3c0-stacking interactions between two viologen units. In the square 2D tiling crystal packing of CB[8] macrocycles, the same site which favors the dimerization observed in the 2:2 complex is also statistically occupied by a single methyl viologen moiety of the 1:1 complex. The rational interpretation of the crystal structure represented an intriguing challenge, due to the complicated statistical disorder in the alkyl chains hosted in CB[8] units and in the methyl viologen moieties of 2:2 and 1:1 complexes. In contrast with the solution behavior dominated by the 2:1 complex, the coexistence of three host-guest complexes with 3:2, 2:2, and 1:1 ratios highlights the fundamental importance of packing effects in the crystallized supramolecular complexes. Therefore, the crystallization process has permitted us to capture different host-guest systems in a single crystal, revealing a supramolecular landscape in a single photo

    Serapias X Marchiorii Turco & Medagli (Serapias Bergonii E. G. Camus X Serapias Politisi Renz) Ibrido naturale nuovo del Salento

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    EnNatural hybridization in the plant kingdom, that particularly occurs in disturbed habitats where is generally considered as a threat for rare and endangered species, is a potent evolutionary force. In fact in Mediterranean orchids, mainly pertaining to the Anacamptys, Ophrys and Serapias genres, the hybridization is a common phenomenon, as a natural consequence of their pollination system, that often it has carried to the defined phenomenon “sympatric speciation”. Here we describe the result of this process as a new Orchidaceae’s hybryd species, belong to Serapias genus, named Serapias x marchiorii Turco & Medagli, through analysis of the morphological aspects. The parental of the new hybrid species are: Serapias bergonii E.G. Camus and Serapias politisi Renz. Serapias bergonii = S. vomeracea (N.L. Burm.) Briq. subsp. laxiflora (Soò) Gölz & Reinhard was originally described as an hybrid entity, result of a discovery made in Corfù at the “Saline of Potamos”. It is a species that is distributed in eastern areas, present in Italy only in the southern Apulia and southern Sicily. Serapias politisi, instead, was originally described as an hybrid between Serapias bergonii and Serapias parviflora at the island of Corfù, then was defined as a species and reported for the mainland Greece, the Aegean’s islands, the western Anatolia and in Apulia, the only Italian region of presence, where it is widespread mostly in Salento. Thus, the ranges of these two entities have little overlap that make rare and localized the interspecific hybrids. This is, probably, the reason that makes the hybrid in question not widely distributed. S. x marchiorii was found in a small area known as “Palude di Cassano” in the town of Melendugno (Le) along the adriatic coast, May 13, 2009. The area of small dimensions, is occupied mostly by a depression in karst nature which was partially drained in the middle of ‘900 with the creation of a drainage channel; the area surrounding the marsh is mainly occupied by grasslands and maquis. The station was found with few plants and was situated at an altitude between 12 and 15m above sea level, on a calcareous substrates known as “Calcareniti del Salento”
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