Taxonomic and functional plant diversity of the Santorini-Christiana island group (Aegean Sea, Greece)

This is the first attempt to analyse vascular plant diversity patterns regarding the seven vegetated islands of the Santorini archipelago (Aegean Sea, Greece) as a whole. Hitherto unpublished floristic records, combined with critical use of taxonomic and chorological information from previous and most recent literature, resulted in a total of 696 infrageneric taxa (species and subspecies) occurring in the area. Detailed qualitative and quantitative phytodiversity spectra per individual island are presented, and floristic dissimilarity (beta-diversity) between islands is considered. Spatial distribution of 28 chorological, ecological, vegetative and reproductive traits for each recorded taxon have been calculated in order to detect regional and fundamental patterns in functional biogeography beyond traditional species-based approaches, based on both taxonomic and functional components of diversity. Mediterranean species constitute the most abundant chorological element and therophytes the most abundant life-form element in the region. Surface area is the most influential variable contributing to species richness; very strong relationships in (1) species per area, (2) functional richness per area and (3) functional richness per species richness are revealed for the Santorini archipelago. Floristic cross-correlations revealed an overall high floristic heterogeneity among the individual islands. The phytodiversity assessment presented is undoubtedly of documentary value in consideration of expected future eruptive events in the area which may damage the plant cover at least on some of the involved islands to a yet unpredictable extent

Microscopic investigation of soot and ash particulate matter derived from biofuel and diesel: implications for the reactivity of soot

Investigation of soot and ash particulate matter deposited in diesel particulate filters (DPFs) operating with biofuel (B100) and diesel (pure diesel: B0 and diesel80/biofuel20 blend: B20) by means of optical microscopy, scanning electron microscopy, and high resolution transmission electron microscopy (HRTEM) reveals the following: the rapeseed methyl ester biofuel used for this study contributes to ash production, mainly of Ca-S- and P-bearing compounds ranging in size between 50 and 300nm. Smaller ash particles are less common and build aggregates. Ash is deposited on the inlet DPF surface, the inlet channel walls, and in B100-DPF at the plugged ends of inlet channels. The presence of Fe-Cr-Ni fragments, down to tens of nanometers in size within the ash is attributed to engine wear. Pt particles (50-400nm large) within the ash indicate that the diesel oxidation catalyst (DOC) upstream of the DPF shows aging effects. Radial cracks on the coating layer of the DOC confirm this assumption. The B100-DPF contains significantly less soot than B20 and B0. Based on the generally accepted view that soot reactivity correlates with the nanostructure of its primary particles, the length and curvature of graphene sheets from biofuel- and diesel-derived soot were measured and computed on the basis of HRTEM images. The results show that biofuel-derived soot can be more easily oxidized than diesel soot, not only during early formation but also during and after considerable particle growth. Differences in the graphene sheet separation distance, degree of crystalline order and size of primary soot particles between the two fuel types are in line with this inferenc

What is a tree in the mediterranean basin hotspot? A critical analysis

Background: Tree species represent 20% of the vascular plant species worldwide and they play a crucial role in the global functioning of the biosphere. The Mediterranean Basin is one of the 36 world biodiversity hotspots, and it is estimated that forests covered 82% of the landscape before the first human impacts, thousands of years ago. However, the spatial distribution of the Mediterranean biodiversity is still imperfectly known, and a focus on tree species constitutes a key issue for understanding forest functioning and develop conservation strategies. Methods: We provide the first comprehensive checklist of all native tree taxa (species and subspecies) present in the Mediterranean-European region (from Portugal to Cyprus). We identified some cases of woody species difficult to categorize as trees that we further called “cryptic trees”. We collected the occurrences of tree taxa by “administrative regions”, i.e. country or large island, and by biogeographical provinces. We studied the species-area relationship, and evaluated the conservation issues for threatened taxa following IUCN criteria. Results: We identified 245 tree taxa that included 210 species and 35 subspecies, belonging to 33 families and 64 genera. It included 46 endemic tree taxa (30 species and 16 subspecies), mainly distributed within a single biogeographical unit. The countries with the highest tree richness are Greece (146 taxa), Italy (133), Albania (122), Spain (155), Macedonia (116), and Croatia (110). The species-area relationship clearly discriminated the richest central-eastern (Balkans) and northern (Alpine and Cevenno-Pyrenean) biogeographical provinces, against the five western provinces in the Iberian Peninsula. We identified 44 unrecognized “cryptic trees”, representing 21% of the total trees. Among the 245 taxa identified, 19 are considered to be threatened (15 CR + EN + VU) or near threatened (4 NT) by IUCN. Conclusions: The Mediterranean-European region includes an unsuspectedly high number of tree taxa, almost 200 tree taxa more than in the central European region. This tree diversity is not distributed evenly and culminates in the central-eastern part of the Mediterranean region, whereas some large Tyrrhenian islands shelter several narrow endemic tree taxa. Few taxa are recognized as threatened in the IUCN Red list, and the vulnerability of these species is probably underestimated.French Foundation for Research on Biodiversity (FRB). Centre for Synthesis and Analysis of Biodiversity data ANR-11-LABX-006

Ceramic foam substrates for automotive catalyst applications: fluid mechanic analysis

Several properties of ceramic foams render them promising substrates for various industrial processes. For automotive applications, the foam properties that need to be further studied include the substrate impact on the exhaust gas flow, in terms of pressure drop and flow uniformity. In this paper, pressure drop measurements are performed with different honeycomb and ceramic foam substrates, and pressure drop correlations are discussed. The flow uniformity upstream and downstream of the substrates is evaluated using particle image velocimetry. The results show that ceramic foam substrates induce higher pressure drop, while increasing the uniformity of the flow. In contrast to honeycomb monoliths, the flow uniformity downstream of ceramic foams does not decrease with increasing flow velocity. The higher flow uniformity of ceramic foams is not only caused by their higher pressure drop, but also by flow homogenization that occurs inside the ceramic foam structure, as a result of the momentum exchange perpendicular to the main flow directio

Modeling of Aqueous Urea Solution injection with characterization of spray-wall cooling effect and risk of onset of wall wetting

AbstractThe definition of a sufficiently resolved heat transfer model with spray cooling effect as a function of each droplet kinetic and thermal parameters is a key factor in the numerical simulation of aqueous urea (AUS) based Selective Catalytic Reduction (SCR) exhaust after-treatment systems.A consolidated spray-wall interaction model [1] has been implemented on the open source 3D finite volume software OpenFOAM and a critical investigation of its behaviour in engine representative conditions is reported.A simplified test case is used to highlight the influence of the chosen model on the numerical simulation of the system, reducing the importance of the other spray sub-models in the Lagrangian-Eulerian computational framework. The coupling between the droplet evaporation heat flux and the gas-solid interface thermal boundary condition has been studied, pointing out the significance of each contribution.The main focus of this work is to present reference conditions to simulate the spray-dry wall spray impingement behavior to determine the ‘onset of wall wetting’ thermal conditions

National scale ecosystem condition assessment with emphasis on forest types in Greece

This study presents a first, national scale approach on ecosystem condition assessment for Greece, through integrating the available surveillance and monitoring data for habitat types, at the plot level, within the Natura 2000 network. The study consists of two parts: (a) ecosystem condition assessment for ecosystem types in Greece, using the conservation degree at plot level as an indicator and (b) a large scale analysis of the forest types' condition using, as indicators, the pressures and typical plant species richness, as an exemplary case to interpret the outcomes of the assessment. The main results of this study revealed that: (i) the majority of the ecosystem types are in above good condition, with the higher percentages of bad condition recorded for wetlands, rivers and lakes, marine inlets and transitional waters, (ii) forest categories in their majority are at above-adequate condition, (iii) at forest ecosystem categories specific pressures (e.g. grazing, cultivations, forestry clearance) act as main drivers forecosystem condition change, (iv) Mediterranean deciduous forests are the most floristic-rich forest category, regarding typical plant species. Simultaneously, it is highlighted that already available datasets could be used for immediate and rapid framework assessments, which will guide future steps on ES studies, research and decision-making

Female–female aggression : structure of interaction and outcome in loggerhead sea turtles

Aggressive behaviour between females of the same species is not widely documented, particularly in marine vertebrates. During a 3 yr in-water survey at the temperate loggerhead sea turtle Caretta caretta breeding area of Zakynthos, Greece, female–female interactions comprised 4% of all female loggerhead sighting events (n = 60 out of 1449 events). Male–female interactions comprised an additional 4% of sighting events, while 92% were of solitary females. The structure of interactions was analysed for 58 of these sighting events, each lasting an average of 3.4 min (SD ± 1) and comprising a total of 3.1 h observation time. We found that interactions involved ritualized escalation in behaviour from passive threat displays (e.g. head–tail circling) to aggressive combat (e.g. sparring). We suggest that circling individuals evaluate opponent size, sparring individuals test opponent strength, and that the positioning of the prehensile tail signals motivational intent to either escalate or abort. The presence of intruder females triggered a passive response in 100% of events involving basking and swimming turtles (n = 19); although residents resting on the seabed only responded on 69% of occasions (n = 27), their response was almost 4 times more likely to escalate to one of aggression. Our results suggest that certain sites may be preferentially sought after and defended by sea turtles

Spatial patterns of genus-level phylogenetic endemism in the tree flora of Mediterranean Europe

Aim: The Mediterranean Basin is a major hotspot of plant biodiversity, including forest trees. Over the past centuries, Mediterranean forests have been fragmented and over-exploited, to which the threats of climate change are now added. Our aim is to better understand patterns and processes of tree biodiversity in the Mediterranean and to provide indicators complementing the traditional approaches to biodiversity conservation based on species counts and occurrences, using georeferenced phylogenetic diversity and endemism analyses in a spatial ecological context. Location: Mediterranean Europe. Methods: Using a dated phylogeny of the 64 Euro-Mediterranean tree genera, we calculated phylogenetic diversity for all 50 × 50 km2 grid cells spanning Mediterranean Europe (n = 643) and compared values with those obtained for genus-level taxonomic diversity. Then, we tested the relative influence of geography, past and present climate, and soil on tree diversity (phylogenetic or taxonomic) and its geographical turnover. Geographical patterns of phylogenetic endemism were inferred using the Categorical Analyses of Neo- and Paleo-Endemism (CANAPE) methodology. Results: We showed that phylogenetic and taxonomic diversity within and among cells are correlated and influenced by soil parameters as well as current, Holocene and Late Glacial Maximum climate. Southern Spain, Cyprus and some Aegean islands contained areas of disproportionately high phylogenetic diversity and a concentration of phylogenetic paleo-endemics, while phylogenetic neo-endemism was high in eastern Sicily. Mixed phylogenetic endemism regions were detected in southern Spain and Portugal, in the Balkans and in Crete. Main conclusions: Our phylogenetic approach provides relevant indicators for better protecting forests of the Mediterranean, encompassing past and present evolutionary processes and factors. We consider areas that show a concentration of evolutionary history manifested by high phylogenetic endemism as high priority targets for the conservation of the European tree flora.Aix-Marseille University ANR-11-LABX-006

Residents' views on landscape and ecosystem services during a wind farm proposal in an island protected area

Industrial wind farms are being developed within many protected areas, such as in EU Natura 2000 sites; this includes proposals on small Mediterranean islands, such as Samothraki in Greece. Scarce wild land areas on islands may be particularly vulnerable to landscape-scale degradation; this may have serious negative societal impacts. Samothraki's resident perceptions were surveyed in the wake of such a proposal, in June 2018. Of 98 respondents, 48% reported they were against the wind farm plan, while 22% did not take sides. We compare for-and-against sub-group perceptions of the proposed wind farm with potential impacts on the landscape and explore residents' opinions on ecosystem services and environmental pressures and threats. Conflict over the wind farm was prevalent; residents most frequently reported that the proposal threatens aesthetic and landscape qualities. Aesthetic qualities were also the second highest ranked ecosystem services, after freshwater provision. However, other threats, such as livestock overgrazing, top residents' opinion of major environmental problems on the island. The questionnaire survey used provides a scoping assessment, which may assist in identifying "conflict hotspots" for wind farm development. A critical review of wind farm planning in protected areas is presented in light of insights gained from this survey and other relevant studies

A multidisciplinary critical review of ecosystem services studies in Greece: approaches, shortcomings and the pathway to implementation

During the last two decades, ecosystem services (ES) research is used to inform the various steps of decision- and policy- making process, regarding environmental management, spatial planning and natural capital accounting. In the EU, this vast and rapid publication boom was triggered by the enactment of Action 5 of the EU Biodiversity Strategy to 2020, urging Member States to implement Mapping and Assessment of Ecosystem and their Services (MAES); few countries pioneered, while others are still lagging behind. In Greece, the implementation of MAES started in 2014 and since then an impressive progress has been made, with Greece now being among the countries with the most rapid progress. However, there are still major knowledge and data gaps on ecosystem services in Greece; know-how on specific methods, tools and practices is still to be developed. This poses obstacles in integrative efforts to identify and/or interpret the various co-variates affecting ecosystems and their services in space and time and hinders the incorporation of the ES generated information into the decision-making process. Making the first steps towards overcoming these hurdles, the present study aims to (i) synthesize the ecosystem services literature relevant to the ES implementation in Greece, (ii) validate and classify each literature source to the relevant ecosystem services categories, (iii) identify shortcomings in terms of ES assessed and data available, and (iv) critically review the variety of approaches to ES assessments that are followed. The outcomes of this study will facilitate the efficient implementation of ecosystem services assessments in Greece