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The biotas of old islands formed from continental terranes usually have a more complex biogeographical history than those of young oceanic islands, including taxa which have originated by vicariance and/or colonisation, over a variety of timescales. The Tyrrhenian Islands of Corsica, Sardinia and the Tuscan Archipelago in the Mediterranean have a complex geological history, shaped by interactions between the African and Eurasian plates since the Mesozoic. Our understanding of the historical biogeography of Tyrrhenian endemics remains limited for many groups, including freshwater invertebrates. Here we use a time-calibrated phylogeny, derived from mitochondrial and nuclear DNA sequence data, to explore the evolutionary history of Tyrrhenian endemic Hydraena water beetles, an ecologically important group in the islands' streams. Whilst no endemic Hydraena appear to date from the initial separation of Corsica-Sardinia from the European mainland in the Oligocene, we show that Tyrrhenian species stem from five colonisation events, occurring at different intervals in the last ca. 15 Ma, at least two endemic lineages apparently arising through isolation at the end of the Messinian Salinity Crisis. Hydraena reflexa Rey, 1884, long considered a geographical form or subspecies of the widespread H. pygmaea Waterhouse, 1833, is reinstated as a valid species, endemic to Corsica and Sardinia. H. reflexa can be distinguished from H. pygmaea on external and aedeagal characters, documented here in detail. Specimens of 'H. reflexa' from southern continental Italy are shown to differ from those on Corsica and Sardinia, having identical male genitalia to H. pygmaea from elsewhere in its range. Genetically, this Calabrian form also clusters with H. pygmaea, and may have arisen through past introgression between a reflexa-like ancestor and H. pygmaea following the connection of the Calabrian block with the nascent Apennines in the Pliocene. The degree of genetic divergence seen between H. pygmaea and H. reflexa suggests that they diverged approximately 5.5 Ma in the Miocene, following the isolation of Corsico-Sardinian and mainland populations at the end of the Messinian. [ABSTRACT FROM AUTHOR]

Formentera was one of the last Mediterranean islands to be colonized by humans at the end of the third millennium BC. This island is rather small (83 km²) with marked biogeographical constraints. Typical of a semi-arid environment, the island is poor in resources and biodiversity. Macrolithic tools from the prehistoric sites of Ca na Costa (ca. 2130-1790 cal BC), Cap de Barbaria II (ca. 1740-900 cal BC), and Sa Cala (ca. 800-570 cal BC) showed similar technological, typological, and functional patterns documented in other prehistoric tool assemblages from the Balearic Islands. This common technology is reflected in the way the raw materials were procured, as well as the manufacture, the maintenance strategies, and the use of macrolithic tools (e.g., grinding stone tools, abraders, and percussion tools). Integrated phytolith and starch analyses from grinding toolkits show evidence of people's exploitating millet-tribe species (Paniceae) during the Bronze Age, cereals that are well-adapted to nutrient-poor soils, including exotic taxa such as possible foxtail millet (Setaria cf. italica). The production and use of this stone technology suggests how the first human communities on the island achieved and shared social knowledge about the insular landscape and its environmental constraints. This integrative archaeological research in Formentera has shown development of a set of innovative, diversified, and intensive resource exploitation strategies, underlining the high adaptability and resilience of prehistoric societies as well as the sharing of technology within the Balearic archipelago and its independent evolution from mainland technologies. [ABSTRACT FROM AUTHOR]

In the Western Alps, a first Late Cretaceous to Eocene “Pyrenean-Provençal” compressive phase accommodating N-S shortening resulting from the convergence between Africa and Eurasia is classically described. It is followed by the Neogene “Alpine phase” accommodating E-W shortening. Since this major tectonic change is not explained by a modification of the global Africa-Eurasia convergence, it should be explained instead by more local causes, possibly by the subduction of the Ligurian Ocean that initiated in the Oligocene beneath the European and Iberian plates. In this paper, we present analogue models simulating the Neogene evolution of this subduction zone, in order to understand how it impacted the regional tectonics. Although models do not include the lithospheric plate overriding the subduction zone, their surface deformations share many similarities with the Neogene tectonics of Western Europe and Iberia. We observe that the tectonic evolution is largely controlled by the roll-back of the slab, that occurred much faster than the Africa-Eurasia convergence. Models reproduce the opening of the Western Mediterranean Basins and the dispersion of the AlKaPeCa continental fragments (Alboran, Kabylian, Peloritan and Calabrian blocks). They also show that the subduction of the Ligurian Ocean favors the counterclockwise rotation of Adria. In more elaborated models, we introduced a pre-existing weakness along the Africa and Adria margins, to reproduce the break-off of the oceanic slab that followed the beginning of continental subduction both in Northern Africa and Adria. Slab break-off is followed by the exhumation of the subducted continent. We observe that the influence of subduction on the kinematics of Adria largely decreases following slab break-off. In the models, the total counterclockwise rotation of Adria varies between 7° and more than 30°, depending on the timing of slab break-off. Since the process of subduction modifies the displacement of Adria, it also impacts the tectonic evolution of surrounding regions, especially in the Alpine belt: Our models show that during slab-roll back and before the Ligurian slab break-off, the azimuth of convergence between Adria and Europe shifts from ∼N-S to ∼ENE-WSW. Hence, they suggest that the oceanic subduction in the Western Mediterranean may contribute to the “Oligocene revolution” described by Dumont et al. (2011), leading to E-W shortening in the Western Alps and to the activation of the Periadriatic right-lateral shear zones in the Central Alps. We conclude that the western Mediterranean region is a spectacular example showing how the tectonics of mountain ranges and plate boundaries may be controlled by distant subduction processes.

Quercus suber L. is a sclerophyllous tree species native to the western Mediterranean, a region that is considered highly vulnerable to increased temperatures and severe dry conditions due to environmental changes. Understanding the population structure and demographics of Q. suber is essential in order to anticipate whether populations at greater risk and the species as a whole have the genetic background and reproductive dynamics to enable rapid adaptation. The genetic diversity of Q. suber has been subject to different studies using both chloroplast and nuclear data, but population structure patterns remain unclear. Here, we perform genetic analyses on Q. suber using 13 nuclear microsatellite markers, and analysed 17 distinct locations across the entire range of the species. Structure analyses revealed that Q. suber may contain three major genetic clusters that likely result from isolation in refugia combined with posterior admixture and putative introgression from other Quercus species. Our results show a more complex structure scenario than previously inferred for Q. suber using nuclear markers and suggest that different southern populations contain high levels of genetic variation that may contribute to the resilience of Q. suber in a context of environmental change and adaptive pressure. [ABSTRACT FROM AUTHOR]

Quercus suber L. is a sclerophyllous tree species native to the western Mediterranean, a region that is considered highly vulnerable to increased temperatures and severe dry conditions due to environmental changes. Understanding the population structure and demographics of Q. suber is essential in order to anticipate whether populations at greater risk and the species as a whole have the genetic background and reproductive dynamics to enable rapid adaptation. The genetic diversity of Q. suber has been subject to different studies using both chloroplast and nuclear data, but population structure patterns remain unclear. Here, we perform genetic analyses on Q. suber using 13 nuclear microsatellite markers, and analysed 17 distinct locations across the entire range of the species. Structure analyses revealed that Q. suber may contain three major genetic clusters that likely result from isolation in refugia combined with posterior admixture and putative introgression from other Quercus species. Our results show a more complex structure scenario than previously inferred for Q. suber using nuclear markers and suggest that different southern populations contain high levels of genetic variation that may contribute to the resilience of Q. suber in a context of environmental change and adaptive pressure.

The present paper focuses on the ability of the European Leaf-toed gecko, Euleptes europaea , an endemic species of the western Mediterranean, to live in low-nutrient habitats. Its distribution is mainly insular and particularly noteworthy is its ability to live on islets and rocks. This work includes data originating from surveys carried out on 111 islands surrounding the island of Corsica (France) in search of herpetofauna. E. europaea is able to survive on the smallest islets, with low habitat complexity, suggesting a pre-adaptation of this species to island life. Moreover, high population densities associated with a low biomass seem to facilitate survival on island. [ABSTRACT FROM AUTHOR]

Flash floods represent one of the natural hazards that causes the greatest number of victims in the Mediterranean area. These processes occur by short and intense rainfall affecting limited areas of a few square kilometers, with rapid hydrological responses. Among the causes of the flood frequency increase in the last decades are the effects of the urban expansion in areas of fluvial pertinence and climatic change, namely the interaction between anthropogenic landforms and hydro-geomorphological dynamics. In this paper the authors show a comparison between flood events with very similar weather-hydrological characteristics and the ground effects occurred in coastal areas of three regions located at the top of a triangle in the Ligurian Sea, namely Liguria, Tuscany and Sardinia. With respect to the meteorological-hydrological hazard, it should be noted that the events analyzed occurred during autumn, in the conditions of a storm system triggered by cyclogenesis on the Genoa Gulf or by the extra-tropical cyclone Cleopatra. The “flash floods” damage recorded in the inhabited areas is due to the vulnerability of the elements at risk in the fluvio-coastal plains examined. There are numerous anthropogenic forcings that have influenced the hydro-geomorphological dynamics and that have led to an increase in risk conditions.

Species respond to global climatic changes in a local context. Understanding this process, including its speed and intensity, is paramount due to the pace at which such changes are currently occurring. Tree species are particularly interesting to study in this regard due to their long generation times, sedentarism, and ecological and economic importance. Quercus suber L. is an evergreen forest tree species of the Fagaceae family with an essentially Western Mediterranean distribution. Despite frequent assessments of the species' evolutionary history, large‐scale genetic studies have mostly relied on plastidial markers, whereas nuclear markers have been used on studies with locally focused sampling strategies. In this work, "Genotyping by sequencing" is used to derive 1,996 single nucleotide polymorphism markers to assess the species' evolutionary history from a nuclear DNA perspective, gain insights into how local adaptation is shaping the species' genetic background, and to forecast how Q. suber may respond to global climatic changes from a genetic perspective. Results reveal (a) an essentially unstructured species, where (b) a balance between gene flow and local adaptation keeps the species' gene pool somewhat homogeneous across its distribution, but still allowing (c) variation clines for the individuals to cope with local conditions. "Risk of Non‐Adaptedness" (RONA) analyses suggest that for the considered variables and most sampled locations, (d) the cork oak should not require large shifts in allele frequencies to survive the predicted climatic changes. Future directions include integrating these results with ecological niche modeling perspectives, improving the RONA methodology, and expanding its use to other species. With the implementation presented in this work, the RONA can now also be easily assessed for other organisms. Quercus suber samples from the species' entire distribution range are used to assess population genetic structure, selection signatures, and risk of non‐adaptedness using GBS. The pyRona software was developed to apply the RONA method in large scale and broader scopes. Results reveal an essentially unstructured species, where a balance between gene flow and local adaptation keeps a somewhat homogeneous gene pool across its distribution, but allowing variation clines for individuals to cope with local conditions. RONA analyses suggest that for most sampled locations, the cork oak should not require large shifts in allele frequencies to survive the predicted climatic changes. [ABSTRACT FROM AUTHOR]

The Tell-Rif (Tell in Algeria and Tunisia; Rif in Morocco) is the orogenic system fringing to the south the West Mediterranean basins. This system comprises three major tectonic-palaeogeographic zones from north to south: (1) the internal zones (AlKaPeCa for Alboran, Kabylies, Peloritan, Calabria) originating from the former northern European margin of the Maghrebian Tethys, (2) the “Flyschs zone” regarded as the former cover of the oceanic domain and (3) the external zones, forming the former southern Maghrebian Tethys margin more or less inverted. The Tell-Rif is interpreted as the direct result of the progressive closure of the Maghrebian Tethys until the collision between AlKaPeCa and Africa and, subsequently, the propagation of the deformation within Africa. This gives a consistent explanation for the offshore Neogene geodynamics and most authors share this simple scenario. Nevertheless, the current geodynamic models do not completely integrate the Tell-Rif geology. Based on the analysis of surface and sub-surface data, we propose a reappraisal of its present-day geometry in terms of geodynamic evolution. We highlight its non-cylindrical nature resulting from both the Mesozoic inheritance and the conditions of the tectonic inversion. During the Early Jurassic, we emphasize the development of NE-SW basins preceding the establishment of an E-W transform corridor connecting the Central Atlantic Ocean with the Ligurian Tethys. The Maghrebian Tethys developed just after, as the result of the Late Jurassic-Early Cretaceous left-lateral spreading between Africa and Iberia. By the Late Cretaceous, the occurrence of several tectonic events is related to the progressive convergence convergence between the two continents. A major pre-Oligocene (pre-35 Ma) compressional event is recorded in the Tell-Rif system. The existence of HP-LT metamorphic rocks associated with fragments of mantle in the External Metamorphic Massifs of the Eastern Rif and Western Tell shows that, at that time, the western part of the North-African margin was involved in a subduction below a deep basin belonging to the Maghrebian Tethys. At the same time, the closure of the West Ligurian Tethys through east-verging subduction led to a shift of the subduction, which jumped to the other side of AlKaPeCa involving both East Ligurian and Maghrebian Tethys. Slab rollback led to the development of the Oligo-Miocene back-arc basins of the West-Mediterranean, reworking the previous West Ligurian Tethys suture. The docking of AlKaPeCa against Africa occurred during the Late Burdigalian (17 Ma). Subsequently, the slab tearing triggered westward and eastward lateral movements that are responsible for the formation of the Gibraltar and Tyrrhenian Arcs respectively. The exhumation of the External Metamorphic Massifs occurred through tectonic underplating during the westward translation of the Alboran Domain. It resulted in the formation of both foredeep and wedge-top basins younger and younger westward. The lack of these elements in the eastern part of the systems signs a different evolution dominated by frontal accretion. In the discussion, we precisely address the origin of the non-cylindrical behavior of the orogenic system and question the mechanisms explaining at large scale the phases of coupling/uncoupling between the major plates.

Based on field work and seismic reflection data, we investigate the Cenozoic tectono-sedimentary evolution offshore and onshore Ibiza allowing the proposal of a new tectonic agenda for the region and its integration in the geodynamic history of the West Mediterranean. The late Oligocene–early Miocene rifting event, which characterizes the Valencia Trough and the Algerian Basin, located north and south of the study area respectively, is also present in Ibiza and particularly well-expressed in the northern part of the island. Among these two rifted basins initiated in the frame of the European Cenozoic Rift System, the Valencia Trough failed rapidly while the Algerian Basin evolved after as a back-arc basin related to the subduction of the Alpine–Maghrebian Tethys. The subsequent middle Miocene compressional deformation was localized by the previous extensional faults, which were either inverted or passively translated depending on their initial orientation. Despite the lateral continuity between the External Betics and the Balearic Promontory, it appears from restored maps that this tectonic event cannot be directly related to the Betic orogen, but results from compressive stresses transmitted through the Algerian Basin. A still active back-arc asthenospheric rise likely explains the stiff behavior of this basin, which has remained poorly deformed up to recent time. During the late Miocene a new extensional episode reworked the southern part of the Balearic Promontory. It is suggested that this extensional deformation developed in a trans-tensional context related to the westward translation of the Alboran Domain and the coeval right-lateral strike-slip movement along the Emile Baudot Escarpment bounding the Algerian Basin to the north. [ABSTRACT FROM AUTHOR]

This study was conducted in order to determine some morphological, yield and quality characteristics of Anatolian sage (Salvia fruticosa Mill.) populations distribution in Aegean and West Mediterranean Region in 2014. 17 plant samples belong to populations collected from Antalya (7), Muğla (6), Aydın (2) and İzmir (2) province were used in this study. Plant height vary to 91,7-140,7 cm, branch number 6,0-9,3, leaf length 6,2-9,3 cm, leaf width 1,6- 3,5 plant diameter 118,3-170,0 cm, green herb yiled 2545,5-4234,4 g/plant, drug herb yield 732-1423,2 g/plant and drug leaves yiled 257-587,6 g/plant between populations in the flora. While essential oil yield vary to 2,6-4,3% between populations, main components and rates the essential oil were determined 1,8-cineole (20,7-46,9%), β-pinene (5,3-11,3%) and camphor (3,8-17,5%) respectively. [ABSTRACT FROM AUTHOR]

This study explores obsidian consumption during the Early/Middle Neolithic Stentinello period (ca. 5600–4000 cal B.C.) on the Italian island of Sicily through the analysis of 622 obsidian artifacts from eight sites in eastern Sicily and the Aeolian Islands. By combining obsidian sourcing by means of portable X-ray fluorescence (pXRF) spectrometry with techno-typological characterization, it is shown that distinctively wide Lipari blades were the primary artifact type used during this period. Our data suggest that the primary reduction of these materials occurred at the source area by local populations, with obsidian being transported from Lipari to eastern Sicily and Calabria in the form of preformed cores. Despite similarities between Sicily and southern Italy in the initial procurement of Lipari obsidian, there are distinct differences in how these materials were subsequently reduced. [ABSTRACT FROM AUTHOR]

Scholars typically argue that cultural interaction between the West Mediterranean islands of Sardinia and Corsica and the European mainland took place through the Tuscan Archipelago, via such intermediary islands as Elba and Pianosa. This path is posited as the prime route in and out of these islands for both people and objects throughout prehistory largely due to the belief that early—pre-sail—seafarers would have wished to avoid more treacherous open-sea voyages. This article tests this hypothesis using social network analysis (SNA) to identify the strengths of inter-site relationships through time based on the relative proportions of West Mediterranean obsidian raw materials at 79 Neolithic sites dating from the sixth to fourth millennia BC. We argue that similar patterns of obsidian consumption reflect similar procurement mechanisms and the likelihood of more frequent interactions between the people of these communities. As such, it becomes possible to reconstruct the relationships that mediated the distribution of obsidian across the landscape. Contrary to previous interpretations highlighting the role of Elba and Pianosa in the exchange of obsidian from the geological sources of Sardinia along the coast to northern Italy and France, our results suggest that obsidian also took a more direct open-sea path upwards of 200 km from Corsica to the coastal regions of Provence and Languedoc in southern France. These results are contextualized within broader patterns of obsidian circulation and use and have important implications for debates surrounding Neolithic obsidian procurement, exchange spheres, and early maritime navigation. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this paper is to describe the mafic rocks that crop out in the central-western Mesorif Zone (External Rif Belt), and discuss their geodynamic signification. Basalt flows, olistoliths and breccias occur in Oxfordian–Berriasian deposits of Mesorif units ascribed to the distal part of the African paleomargin. The climax of volcanic activity is observed at the northern border of a Kimmeridgian carbonate platform progressively dismembered during the Tithonian–Berriasian. In spite of the alteration of the basalts, their petrological and geochemical characters point to E-MORB affinities. The studied gabbro massifs (Bou Adel, Kef el Rhar west and north) occur as restricted slivers or klippes within the Senhadja nappe or mélange of the internal Mesorif, which overlies the basalt-bearing units and other, more external Mesorif units. The compositions range from troctolitic olivine gabbro to ferrogabbro with frequent ortho- to heteradcumulate textures; they display typical tholeiitic affinity. The gabbro massifs are crosscut by trondjhemite dykes and overlain by metabasalts, fault-scarp breccias, ophicalcites, marbles and radiolarites. Composition featuring initial near liquid composition, display multi elements patterns close to those of E-MORB, with a weak Eu negative anomaly and evidence of slight crustal contamination. These gabbro massifs were regarded as Jurassic–Cretaceous intrusions, locally dated (K–Ar) at 166±3Ma. Conversely, we assume they represent discrete samples of a Jurassic–Cretaceous oceanic basement (ophiolites), emplaced tectonically in the Senhadja nappe (mélange) of the central Mesorif. The correlation of both these types of mafic rock associations (paleomargin basalts and ophiolite klippes) with the serpentinites of the eastern Mesorif (Beni Malek) and Oran mountains (Algeria) is then briefly discussed. We conclude that the previous hypothesis of an intramargin “Mesorif suture zone” must be reconsidered, being challenged by that of a major, syn-collisional “Oran-Mesorif Strike-Slip Fault”. In the latter hypothesis, the newly described Mesorif oceanic klippes would represent allochthonous remnants of the Ligurian–Maghrebian (Tethyan) oceanic domain. [Copyright &y& Elsevier]

Abstract: The North Atlantic Oscillation (NAO) has been identified as one of the atmospheric patterns which mostly influence the temporal evolution of precipitation and temperature in the Mediterranean area. Recently, the Western Mediterranean Oscillation (WeMO) has also been proposed to describe the precipitation variability in the eastern Iberian Peninsula. This paper examines whether the chemical signature and/or the chemical deposition amounts recorded over NE Iberian Peninsula are influenced by these climatic variability patterns. Results show a more relevant role of the WeMO compared to NAO in the deposition of either marine (Cl−, Na+, Mg2+) or anthropogenic pollutants (H+, NH4 +, NO3 − and SO4 2−). A cluster classification of provenances indicated that in winter (December to March) fast Atlantic air flows correspond to positive WeMO indices, while negative WeMOi are associated to Northeastern and Southwestern circulations. The negative phase of WeMO causes the entry of air masses from the Mediterranean into the Iberian Peninsula, that are enriched with marine ions and ions of anthropogenic origin (NH4 +, NO3 − and SO4 2−). For these later, this suggests the advection over the Mediterranean of polluted air masses from southern Europe and the scavenging and deposition of this pollution by precipitation during the WeMO negative phases. This will carry transboundary pollutants to the NE Iberian Peninsula. However, local pollutants may also contribute, as precipitation events from the Mediterranean and the Atlantic (associated to both WeMO phases) may incorporate emissions that accumulate locally during the winter anticyclonic episodes typical of the region. [Copyright &y& Elsevier]

Abstract: This study represents a contribution towards an understanding of the nature of obsidian exploitation in Sardinia during the Chalcolithic (ca. 3200–2200 cal B.C.). A total of 154 obsidian artifacts from Bingia 'e Monti in south-central Sardinia was techno-typologically characterized. Of these, 146 were elementally analyzed employing energy-dispersive X-ray fluorescence (EDXRF) as a means of sourcing the raw materials. It is argued that the community's residents obtained obsidian directly from Sardinian source areas, then reduced the material on-site for the production of lunates and expedient flake tools. By contextualizing the study within a broader consideration of obsidian distribution and use within Sardinia, it is shown that obsidian exploitation at this time differs from earlier periods, arguably related to a reconfiguration of socio-economic interaction spheres and exchange networks. [Copyright &y& Elsevier]

In this study, leading the country in greenhouse greenhouse structures, the structural characteristics of the western Mediterranean region were investigated. In this context, the structure of the region 13 counties total of 212 sera were selected by random sampling method. These selected greenhouse construction and existing structures were examined in terms of physical conditions. Greenhouses, organization types (single or block Greenhouse), based on construction materials (steel or galvanized plate), by covering materials (glass or plastic sheeting), roofing types (bow-roofed (gothic) or flat roofs), roof pitch angles according to (standards (TS EN 13031-1) standard or standards (TS EN 13031-1) improper) and greenhouse planning (with a project-project) are classified in terms of the distribution of the sample in the region given in graphs. [ABSTRACT FROM AUTHOR]

Aim Distinct insular populations are generally considered important units for conservation. In island-mainland situations, unidirectional introgressive gene flow from the most abundant, typically continental, populations into the smaller island populations can erase native insular genetic units. As an indication of threat, the concept of phenetic slope is developed, a measure proportional to differentiation and to geographical proximity. Location The Western Mediterranean, including the following islands: Sardinia, Sicily, Corsica, Balearics, circum-Italian, circum-Sicilian and circum-Sardo-Corsican archipelagos. Eastern Europe is included for comparison. Methods Geometric morphometrics was applied to 2392 male genitalia of seven butterfly species groups. Geographic Information System techniques were used to depict the pattern in the distribution of morphotypes. The slope of variation in genital shape was computed to highlight geographical areas showing abrupt morphological changes. Correlation analyses were performed between the mean slope values across sea straits separating islands and nearest sources and ecological traits of the species that underlie their colonization and migration capacity. Results Phenetic slope analysis has revealed that the strait of Messina and the northern Tyrrhenian Sea support particularly contrasting populations. In these areas, mean slopes for species also correlated with certain ecological traits of the species. Sardinia emerges as the most stable refugium for ancestral mediterranean populations. Main conclusions There is strong support for the hypothesis that Italy has experienced invasion by populations from Eastern Europe with postglacial expansion of these populations across Italy. However, propagules are impeded from invading islands by the expanse of sea straits. Even so, sea straits are not invariably barriers. Our results suggest that wind direction in combination with habitat occupancy may have maintained ancestral insular populations in key locations distinguished by phenetic compression. We conclude that native insular populations acting as barriers to introgression in the areas showing particularly steep phenetic slopes deserve attention in conservation programmes. [ABSTRACT FROM AUTHOR]

Genetic differences in the Posidonia oceanica meadow of Monterosso al Mare (NW Mediterranean, Marine Protected Areas (MPAs) 'Cinque Terre') were compared in three stations, at an increasing distance from a source of impact (beach nourishment) in the recent decade. Random amplified polymorphic DNA analysis showed a higher genetic variability (>20 %) in the area directly subjected to the stress, increasing with time. Clone integration, confirmed by phenotypic analysis, showed increases both in shoot density and leaf length connected to genetic differences observed in DNA fingerprints of new shoots. Analysis of molecular variance (AMOVA) showed 45 % individual differences within populations and 54 % among the populations. The fixation index ( F = 0.54), of the genetic differentiation, showed a marked difference between the populations at different temporal scales. Over a decade AMOVA indicated genetic variations from 28 % (1998) to 54 % (2009). These results make it clear that in the P. oceanica population examined the environment had, in ten years, selected those clones which were more resistant to the anthropogenic impact, despite being subjected to the effects of the resuspension of fine sediments. These findings could help to explain both the survival of the regressed Mediterranean P. oceanica meadows in areas subjected to moderate impacts and the extreme variability in success of revegetation experiments. Management of the ecological disturbance here described indicates also the timescale in population response to stress and its increased resilience in MPAs. [ABSTRACT FROM AUTHOR]

An external genetic input of Posidonia oceanica fruits dispersed by currents in the Ligurian Sea (Western Mediterranean) was investigated. During 2003-2004, when a massive fruiting event occurred, fruits were collected from plants at Monterosso al Mare (meadow) and compared with stranded fruits sampled in front of the meadow and downcurrent in Tuscany along 80 km of the coast. After their growth in culture, the plants were analysed using 10 random amplified polymorphic DNA (RAPD) molecular markers. Cluster analysis of similarity showed four distinct genetic populations. One group included parental plants from Monterosso and stranded fruits with the same genetic traits. The second group was formed by fruits stranded in the southern sector (Tuscany), and the third and the fourth groups were samples taken onshore, in front of the meadow, which appeared very different from the other two groups. Results evidenced the probability of the arrival of a new genetic population of nearly 40%, and it seems likely that the stranded fruits of external provenance did not come from the nearest P. oceanica meadows of Tuscany but were probably carried ashore by the Corsica current, as supported by an oceanographic analysis. [ABSTRACT FROM AUTHOR]