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Invasive alien plants (IAP) pose a major threat to biodiversity and have a negative impact on the integrity and conservation status of plant communities. Mediterranean dunes are widely exposed to IAP, due to their environmental heterogeneity and the anthropogenic pressures to which they are subjected. The current study explored the possible existence of critical thresholds of IAP cover/abundance and dune path impacts that may cause the decline in diagnostic species cover in shifting and transition dunes. A random sampling of 126 plots in areas invaded and not invaded by IAP across the Italian Adriatic dunes has been used and the recorded species have been classified in ecological guilds. In order to explore the effect of plant community composition and distances from dune paths on the diagnostic species cover, a Random Forest regression model has been fitted. The results revealed that three main critical thresholds can be detected concerning IAP total cover, IAP Oenothera stucchii Soldano abundance and the distance from dune paths and they work differently in shifting and transition dunes. The identification of such cut-off points provides useful insights for an array of actions to preserve the biodiversity of the Mediterranean coastal dunes.

In the Mediterranean sandy coasts, urban expansion mainly occurs to support seaside tourism, causing a drastic loss of natural coastal dune habitats and the associated ecosystem services. We investigated on a representative tract of the Mediterranean coast to which extent land conversion into urban areas affected natural dune ecosystems and the related recreational Ecosystem Service over 50 years. Using empirical data derived from 591 questionnaires of beach users, we quantified the recreational ecosystem service (ESR) provided by the main dune habitat types of the Adriatic coast (Beach with Pioneer annual Vegetation, Herbaceous Dune Vegetation and Mediterranean macchia). On the basis of detailed multi-temporal land cover maps (years 1954, 1986 and 2006), we quantified the conversion of natural dune habitats into urban areas over time, by means of transition matrices. By combining the results of the assessment of ESR with the transition matrices, we measured how the natural dune habitats’ loss reduced the related ESR supply. Results show that although natural dune habitats have an important role as ESR suppliers, urban expansion eroded them with specific rates, causing a total percent loss of 12% in the ESR. Our work underlines the fragility of natural coastal dunes, which during the last decades have become a privileged destination for touristic and recreational activities and, thus, have been progressively replaced by urban areas, with an unwanted direct impact on their ESR supply. By combining multi-temporal mapping techniques with ecosystem services measurements, we enhanced our understanding of transformation processes on coastal dunes, offering as well new insights for dune management. According to our results, an effective dune management shall favor natural dune zonation, by welcoming sustainable sea-side recreational activities as the only acceptable form of coastal tourism.

Beach litter accumulation patterns are influenced by biotic and abiotic factors, as well as by the distribution of anthropogenic sources. Although the importance of comprehensive approaches to deal with anthropogenic litter pollution is acknowledged, integrated studies including geomorphologic, biotic, and anthropic factors in relation to beach debris accumulation are still needed. In this perspective, Species Distribution Models (SDMs) might represent an appropriate tool to predict litter accumulation probability in relation to environmental conditions. In this context, we explored the applicability of a SDM&ndash, type modelling approach (a Litter Distribution Model, LDM) to map litter accumulation in coastal sand dunes. Starting from 180 litter sampling plots combined with fine&ndash, resolution variables, we calibrated LDMs from litter items classified either by their material type or origin. We also mapped litter accumulation hotspots. LDMs achieved fair-to-good predictive performance, with LDMs for litter classified by material type performing significantly better than models for litter classified by origin. Accumulation hotspots were mostly localized along the beach, by beach accesses, and at river mouths. In light of the promising results achieved by LDMs in this study, we conclude that this tool can be successfully applied within a coastal litter management context.

The Interreg Adrion ‘APPRODI’ project aims at a qualitative change in the nature of tourism demand with a transnational approach and at increasing visibility of destinations. the project will allow to create the conditions for development of cultural tourism, even underwater, increasing and enhancing the historical and archaeological resources. The dive samplings allowed to find an important archaeological heritage in the seabeds in front of Ortona coast, testifying to the presence of an ancient port and maritime traffic.

LIFE17 NAT/IT/000565 CALLIOPE aims to improve the coast-sea regional natural connectivity by improving the Natura 2000 Network. The main objectives are: improving the biodiversity knowledge of marine environments, testing integrated management strategies to increase the conservation of coastal-marine biodiversity and supporting the preparation of a Coastal Action Plan for the Abruzzo Region. We identified and mapped the HD-1110 here dominated by Cymodocea nodosa, the HD-1160 with the presence Zostera noltii and in correspondence of rocky environments the HD-1170.

Beach litter is an increasingly important threat, causing a drastic loss of natural biodiversity and the associated ecosystem services. Even if beach litter accumulation in oceanic coasts has been analyzed quite well, new research efforts are still necessary to better understand this phenomenon along the Mediterranean coasts. This work sets out to analyze the sources of beach litter, the type of material, and the distribution and accumulation trend along the sandy coasts of the Adriatic Sea in central Italy (Abruzzo and Molise Regions, Italy). In particular, we focus on the following questions: (i) Which are the most frequent beach litter items and materials on sandy coasts? (ii) How is beach litter distributed on the different coastal dune habitats along the sea–inland gradient? Data were collected and categorized during spring 2014–2015 following the OSPAR guidelines in belts parallel to the shoreline and in transects perpendicular to the shoreline. Before analyzing litter abundance by classes of material, source types, and floating capacity, the spatial trends of waste accumulation along the dune zonation was also explored. Most of litter elements are in plastic, followed by styrofoam with good floating capacity. Majority of the debris derive from food packaging, fishing and recreational activities. The distribution of litter along the sea–land eco-morphological gradient is heterogeneous. The unequal accumulation amounts of debris on the upper beach, embryodunes, mobile dunes and fixed dunes threaten natural EC habitats in different ways. Our results stress the need of specific conservation and cleaning actions able to preserve the ecological value of EC coastal dune habitats.

Beach litter threatens coastal dunes integrity across the world. European countries are committed to improving the environmental status of the marine and coastal environment by 2020, and to do this, they need to reduce the gap of knowledge about litter accumulation patterns in coastal environments. We analyzed the distribution pattern of waste, differentiated by material and origin, in the coastal dune vegetation mosaic along protected natural areas in the Adriatic seashore (central Italy). Litter data were collected following a random stratified procedure. We registered litter occurrence on 180 (2 &times, 2 m) sampling plots randomly distributed in the different habitats of European conservation concern mapped for the analyzed protected areas. Litter was classified by origin and material, and their abundance on different habitats was explored by multivariate ordination techniques and tested by nonparametric ANOVA followed by Mann-Whitney pairwise post-hoc tests. Most of the plots included at least one waste element being plastic. Plastic was the most abundant material, and fishing and touristic the most polluting activities. Waste distribution varies across coastal dune vegetation types and involves the back dune zone too. Our results stress the need for (a) specific cleaning tasks able to preserve the ecological value of coastal dune habitats and (b) actions aimed at preventing litter production and accumulation.

Coastal sand dunes are complex transitional systems hosting high levels of biodiversity and providing important benefits to society. In this paper we aimed to evaluate the multi-service nature of ecosystem services (ES) supply in the dunes of the Italian Adriatic coast within Natura 2000 (N2K) sites. We i) identified ES indicators and assessed the supply capacity (Climate regulation, Protection from wind and aerosol, Erosion regulation, Recreation and Tourism and Existence value of biodiversity) of natural dune ecosystems of European conservation concern; ii) upscaled this data to create an inventory of ES supply for all dune N2K sites in the study area; iii) explored the trade-offs among ES; and iv) summarized and spatially compared the overall multi-service value of the N2K sites. The study provides a method for quantifying the role of N2K sites in supplying benefits for our society. We found that the multi-service capacity of coastal dunes is uneven within sites and within administrative regions. This variability is related to both ecological (e.g. distribution, ecological integrity, extent and conservation status of dune habitats) and administrative (e.g. local implementation of the Habitats Directive) characteristics of the analysed area. ES are not coupled as several sites with high values for one ES show very low values for others. The results suggest that conservation actions should favour restoration of the natural dune zonation, since this underpins multi-service ES supply. The approach can distinguish regions with high ES values and regions where the paucity of protected areas represents a gap in ES supply, fact that offers an incentive to enhance the protection strategy but also suggests an urgent need to improve the N2K network by enlarging existent sites and including new ones.

Recent market trends in self-driving technology have revived the attention on vehicular networks, posing a demand for intelligent solutions supporting the proliferation of many useful applications. Inter-vehicular communication presents an opportunity, capable of providing the basis for localized, timely, collective intelligence. In this context, critical safety applications are particularly challenging, urging for quick multi-hop message propagation schemes within an area of interest. The anycast communication model embodied by safety applications and the shared broadcast medium demand for intelligent message propagation schemes minimizing latency. To this end, the state of the art approach is based on having different contention windows among vehicles so as to probabilistically select specific ones as forwarders in order to reduce the number of hops and transmissions needed to propagate the message. However, this solution has been mainly studied empirically. In this article, we present and discuss an analytical model, shedding light on the expected behavior and performance of such approach, along with a validation analysis conducted through the well known simulator NS-2.

Given an undirected graph, the Constrained Domatic Bipartition Problem (CDBP) consists in determining a bipartition, if it exists, of the nodes into two dominating sets, with the additional constraint that one of the two subsets has a given cardinality. The problem is NP-hard in general and in this paper we focus on trees. First, we provide explicit solutions in simple cases, i.e., stars and paths. Then, we provide a polyhedral representation for all domatic bipartitions of a tree. Although the matrix associated with the polyhedron is not totally unimodular, we prove that all its vertices have integral components. Adding the cardinality constraint, the resulting polyhedron will generally lose this property. We then propose a constructive, dynamic programming algorithm for CDBP on trees, that is able to simultaneously find a solution for all possible cardinalities. The proposed algorithm is polynomial with complexity O ( n 3 ) , where n is the number of nodes. Finally, we discuss the extension of CDBP to the weighted case, show that it is NP-hard and provide a pseudo-polynomial algorithm for the problem.

Feeding adaptation, social behaviour, and interspecific interactions related to sexual dimorphism and allometric growth are particularly challenging to be investigated in the high sexual monomorphic Delphinidae. We used geometric morphometrics to extensively explore sexual dimorphism and ontogenetic allometry of different projections of the skull and the mandible of the bottlenose dolphin Tursiops truncatus. Two-dimensional landmarks were recorded on the dorsal, ventral, lateral, and occipital views of the skull, and on the lateral view of the left and the right mandible of 104 specimens from the Mediterranean and the North Seas, differing environmental condition and degree of interspecific associations. Landmark configurations were transformed, standardized and superimposed through a Generalized Procrustes Analysis. Size and shape differences between adult males and females were respectively evaluated through ANOVA on centroid size, Procrustes ANOVA on Procrustes distances, and MANOVA on Procrustes coordinates. Ontogenetic allometry was investigated by multivariate regression of shape coordinates on centroid size in the largest homogenous sample from the North Sea. Results evidenced sexual dimorphic asymmetric traits only detected in the adults of the North Sea bottlenose dolphins living in monospecific associations, with females bearing a marked incision of the cavity hosting the left tympanic bulla. These differences were related to a more refined echolocalization system that likely enhances the exploitation of local resources by philopatric females. Distinct shape in immature versus mature stages and asymmetric changes in postnatal allometry of dorsal and occipital traits, suggest that differences between males and females are established early during growth. Allometric growth trajectories differed between males and females for the ventral view of the skull. Allometric trajectories differed among projections of skull and mandible, and were related to dietary shifts experienced by subadults and adults.

A set of independent machines dedicated to different production processes and sharing, one common resource is modelled as a set of M/M/1 queueing systems whose service rates are subject to a linear constraint. We consider a cost function which depends on the service rates of the queueing systems and on a set of time parameters, the lead times. After proving that there exists a set of service rates and lead times which minimize the cost function, we suggest a method to find it through the solution of a sequence of. auxiliary problems.

Perfect graphs and perfect 0, 1 matrices are well studied in the literature. Here we introduce perfect 0, ± 1 matrices. Our main result is a characterization of these matrices in terms of a family of perfect 0, 1 matrices.

Phenotypic changes in the mammalian mandible can occur at different spatial and temporal scales. We investigated mandibular size and shape variation in three extant closely related dolphins (Cetacea, Odontoceti): Tursiops truncatus, Stenella coeruleoalba and Delphinus delphis in order to test the hypothesis that similar phenotypic changes occur across the same geographical gradient. Our data included 219 specimens representative of the following geographic locations: the Mediterranean Sea, the eastern north Atlantic and the North Sea. Each mandibula was photographed laterally and spatial positioning of eight homologous 2D landmarks was recorded. After applying generalised Procrustes analysis (GPA), intraspecific variation was first investigated between sexes and among populations to allow further pooling of samples. Size and shape differences among populations and species were investigated through multivariate ordination techniques (PCA), Procrustes ANOVA and allometric analyses. In all three species, Mediterranean populations clearly differed in mandible shape from the extra-Mediterranean ones. Among the three, the direction of geographic phenotypic changes was significantly similar in the striped and common dolphin, while the bottlenose dolphin was the most divergent species, differing both in size and allometric trajectory. Shape variation of the two former species highlighted a morphological convergence in the Atlantic, and a phenotypic divergence in the Mediterranean. Shape differences among the three dolphin species were interpreted in the light of different prey preferences, feeding strategies and habitat partitioning to avoid direct competition.