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a The Natural History Museum, Cromwell Road, London, SW7 5BD, UK; b Department of Plant and Animal Production, Munzur University, Vocational School of Tunceli, Tunceli, Turkey; c International School of Advanced Studies, University of Camerino, Camerino (MC), Italy; d Grupo de Investigación Biología para la Conservación, Universidad Pedagógica y Tecnológica de Colombia, Colombia; e Botanical Survey of India, Central National Herbarium, Howrah, India; f Botanical Garden-Institute, Russian Academy of Science, Vladivostok, Russia; g Viale Rovereto, Trento, Italy; h Department of Botany, Kherson State University, Kherson, Ukraine; i Kherson Branch of Admiral Makarov University, Kherson, Ukraine; j Institute of Industrial Ecology Problems of the North of the Kola Science Center of RAS, Apatity, Murmansk Province, Russia; k University of Insubria, Varese, Italy; l Departamento de Biología Vegetal (Botánica), Facultad de Biología, Universidad de Murcia, E-30100, Murcia, Spain; mTeam of Ecological Survey Research, National Institute of Ecology, Seocheon, Korea; n Departamento de Biología (Botánica), Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain; o Centro de Investigación en Biodiversidad y Cambio Global, Madrid, Spain; p Institute of Biology Komi Science Centre UB RAS, Kommunisticheskaja St., 28, Syktyvkar, 167982, Komi Republic, Russia; q Botanical Museum, P.O. Box 7, FI-00014 University of Helsinki, Helsinki, Finland; r Department of Landscape Architecture, Faculty of Architecture, Niğde Ömer Halisdemir University, Niğde, Turkey; s Geobotany Department, Lomonosov Moscow State University, Moscow, Russia; t Botanical Garden-Institute, Far East Branch of Russian Academy of Sciences, Vladivostok, Russia; u Departamento de Biodiversidad, Ecología y Evolución, Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain; v Departamento de Botánica y Geología, Facultad de Farmacia, Universidad de Valencia, Avda, Vicente Andrés Estellés s/n, E-46100 Burjassot, Spain; wDepartment of Systematics, Biodiversity and Evolution of Plants, Albrecht von Haller Institute, University of Göttingen, 37073 Göttingen, Germany; x Donceel, Belgium; y Conservatoire Botanique National du Massif Central, Chavaniac, Laffayette, France; z Plant Resources Division, National Institute of Biological Resources, Incheon, Korea; aaAdnan Menderes Üniversitesi, Fen Edebiyat Fakültesi, Biyoloji Bölümü, TR-09010 Kepez-Aydin, Turkey; abPolar-Alpine Botanical Garden, Kola Science Centre, Russian Acadamy of Science, Kirovsk-6, Murmansk Province 184256, Russia; acInstitute of Botany, University of Natural Resources and Life Sciences Vienna, Vienna, Austria; adDepartment of Botany, University of South Bohemia, České Budějovice, Czech Republic; aeFreie Universität Berlin, Institut für Biologie, Systematische Botanik und Pflanzengeographie, Altensteinstr, 6, D-14195 Berlin, Germany; afKomarov Botanical Institute of the Russian Academy of Sciences, St. Petersburg, Russia; agDepartment of Botany, University of Calcutta, Kolkata, India; ahTetbury, Gloucestershire, UK; aiDepartment of Botany, University of British Columbia, Vancouver, British Columbia, Canada; ajValkenswaard, The Netherlands; akLicenciatura en Biología, Universidad Distrital Francisco José de Caldas, Torre de Laboratorios, Bogotá, Colombia; alMTA Centre for Ecological Research, Institute of Ecology and Botany, Vácrátót, Hungary; am51 Wood Street, Wallingford, Oxfordshire, OX10 0AX, UK; anDepartamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Brazil; aoDepartment of Environmental and Life Science, University of Cagliari, Sardinia, Italy; apCera dos Pomares, Aljezur, Portugal; aqKomarov Botanical Institute of the Russian Academy of Sciences, St. Petersburg, Russia; arDepartment of Biological, Geological and Environmental Biology, University of Catania, Catania, Italy; asCSIR-National Botanical Research Institute, Rana Pratap Marg, Lucknow, India; atThe Ministry of Forests, Lands, Natural Resource Operations and Rural Development, B. C. Government, Victoria, British Columbia, Canada; auDepartment of Botany, Bijoy Krishna Girls’ College, Howrah, West Bengal, India; avCenter for Biodiversity Research and Extension in Mindanao (CEBREM), Central Mindanao University, Musuan, Bukidnon Province, 8710 Mindanao Island, Philippines; awDepartamento de Botánica y Geología, Facultad de Ciencias Biológicas, Universitat de València, Avda. Dr. Moliner 50, E-46100, Burjassot, Valencia, Spain; axVia Selvotta, Muzzana del Turgnano, Udine, Italy; ayInstitute of Environmental Sciences, Kazan Federal University, Kazan, Tatarstan Republic, Russia; azCalifornia Academy of Sciences (CAS), 55 Music Concourse Drive, Golden Gate Park, San Francisco, CA 94118, USA; baInstitute of Biology Bucharest of Romanian Academy, 296 Splaiul Independentei, 060031 Bucharest, P.O. Box 56-53, Romania; bbDepartment of Biology, Faculty of Science and Letters, Aksaray University, Aksaray, Turkey; bcDepartment of Forest Engineering, Faculty of Forestry, Çankırı Karatekin University, Çankırı, Turkey; bdInstitute of Botany and Biodiversity Research, University of Vienna, Vienna, Austria; beMissouri Botanical Garden, 4344 Shaw Boulavard, St. Louis, Missouri, 63110, USA

The young (50-400 Myr) A3V star $\beta$ Leo is a primary target to study the formation history and evolution of extrasolar planetary systems as one of the few stars with known hot ($\sim$1600$^\circ$K), warm ($\sim$600$^\circ$K), and cold ($\sim$120$^\circ$K) dust belt components. In this paper, we present deep mid-infrared measurements of the warm dust brightness obtained with the Large Binocular Telescope Interferometer (LBTI) as part of its exozodiacal dust survey (HOSTS). The measured excess is 0.47\%$\pm$0.050\% within the central 1.5 au, rising to 0.81\%$\pm$0.026\% within 4.5 au, outside the habitable zone of $\beta$~Leo. This dust level is 50 $\pm$ 10 times greater than in the solar system's zodiacal cloud. Poynting-Robertson drag on the cold dust detected by Spitzer and Herschel under-predicts the dust present in the habitable zone of $\beta$~Leo, suggesting an additional delivery mechanism (e.g.,~comets) or an additional belt at $\sim$5.5 au. A model of these dust components is provided which implies the absence of planets more than a few Saturn masses between $\sim$5 au and the outer belt at $\sim$40 au. We also observationally constrain giant planets with the LBTI imaging channel at 3.8~$\mu$m wavelength. Assuming an age of 50 Myr, any planet in the system between approximately 5 au to 50 au must be less than a few Jupiter masses, consistent with our dust model. Taken together, these observations showcase the deep contrasts and detection capabilities attainable by the LBTI for both warm exozodiacal dust and giant exoplanets in or near the habitable zone of nearby stars., Comment: 11 pages, 9 figures, accepted for publication in Astronomical Journal

IDPlanT is the Italian Database of Plant Translocation, an initiative of the Nature Conservation Working Group of the Italian Botanical Society. IDPlanT currently includes 185 plant translocations. The establishment of a national database on plant translocation is a key step forward in data sharing and techniques improvement in this field of plant conservation. Supplemental data for this article is available online at https://doi.org/10.1080/11263504.2021.1985004.

With the exception of the two prime focus cameras, all the instruments on the Large Binocular Telescope (LBT) use the two advanced 672-voice-coil-actuators adaptive secondary mirrors (ASMs). Based on 10 years of ASMs operation experience, and taking advantage of new technology developments, we decided to upgrade some of the ASMs hardware, to increase their performance and reliability. In this paper, we describe these improvements, i.e., upgrade of the power backplanes used in the ASM electronic control system, integration of an accelerometer-based tip-tilt vibration suppression system and upgrade of the optical calibration interferometers.

The adaptive secondary mirrors (ASMs), being an integral part of the telescope optical train, have huge advantages over other wave-front correctors. At the same time, because of this specific characteristic, high performance and high reliability is required from an ASM. In this paper, we report on algorithm/software developments at the Large Binocular Telescope designed to improve performance and reliability of the two 672-voice-coil-actuators ASMs. By making use of the ASMs telemetry, we are able to intervene when critical condition occurs, monitor the daily operation of the ASMs and review the long-term trends to plan future maintenance activities.

During the past decades, the montane and subalpine belts of many European mountains experienced agricultural land abandonment followed by spontaneous recolonization of trees and shrubs on semi-natural mountain grasslands, potentially leading to severe losses in biodiversity. Here we analyse the spatial and temporal patterns of forest encroachment of a Prealpine study site in Northern Italy (Triangolo Lariano, Como) since 1954 in response to land use change and aim to assess whether this process has been accelerated by recent climate warming and atmospheric CO2 increase. To achieve a detailed reconstruction of forest encroachment dynamics, we adopted a multidisciplinary integrated approach, involving dendrochronological and phytosociological analyses, and vegetation mapping. Available maps updated with aerial photographs allowed the delineation of the forest distribution and changes of forest boundaries. Accordingly, along nine elevational transects, 60 plots were set within different forest-grassland successional stages in order to integrate vegetation mapping with phytosociological analyses and reconstruct the recruitment rates through dendrochronological analyses. Since 1954, the forest encroachment process occurred across an elevation range of 185 m, at a mean rate of 29 m per decade, although with uneven temporal and spatial trends. The forest encroachment rates increased progressively with time, from +0.8%/y (1954–1993) to +2.4%/y (1993–2015) to +4.9%/y (2015–2018). The air warming exhibited an increasing trend too, especially in the last twenty years. Betula pendula was the most abundant species responsible for this process (the only one presenting seedlings and saplings settling along the summit areas) and showed two recruitment peaks: the first in concomitance with the abandonment of the agro-silvo-pastoral practices (1950/60s), but the largest recruitment was detected with the increased air warming since early 2000s. The correlation analysis confirmed that forest encroachment was related to air warming (in particular summer warming), land use change and increase of atmospheric CO2 and that it was further accelerated in concomitance with further air warming in the recent decades. The forest encroachment process on semi-natural grasslands triggered by land use change on European mountains and its recent acceleration in response to climate warming represent an increasing threat to biodiversity, leading to potential habitat and species loss, especially of the most vulnerable habitats.

The importance of heathlands as habitats for plants and thus for nature conservation is recognized by European Directive 92/43 (Habitats Directive). However, heathlands are threatened by habitat lo...

Trait‐based approaches are widely used in community ecology and invasion biology to unravel underlying mechanisms of vegetation dynamics. Although fundamental trade‐offs between specific traits and invasibility are well described among terrestrial plants, little is known about their role and function in aquatic plant species. In this study, we examine the functional differences of aquatic alien and native plants stating that alien and native species differ in selected leaf traits. Our investigation is based on 60 taxa (21 alien and 39 native) collected from 22 freshwater units of Hungarian and Italian lowlands and highlands. Linear mixed models were used to investigate the effects of nativeness on four fundamental traits (leaf area, leaf dry matter content, specific leaf area, and leaf nitrogen content), while the influence of growth‐form, altitude, and site were employed simultaneously. We found significantly higher values of leaf areas and significantly lower values of specific leaf areas for alien species if growth‐form was included in the model as an additional predictor.We showed that the trait‐based approach of autochthony can apply to aquatic environments similar to terrestrial ones, and leaf traits have relevance in explaining aquatic plant ecology whether traits are combined with growth‐forms as a fixed factor. Our results confirm the importance of traits related to competitive ability in the process of aquatic plant invasions. Alien aquatic plants can be characterized as species producing soft leaves faster. We argue that the functional traits of alien aquatic plants are strongly growth‐form dependent. Using the trait‐based approach, we found reliable characteristics of aquatic plants related to species invasions, which might be used, for example, in conservation management.

[Wetlands are extremely important ecosystems for supporting biodiversity and providing services. Nonetheless, although they are mostly protected through several regulations, wetlands are affected by many negative factors that are leading to progressive deterioration of their conservation status. This circumstance is especially obvious in the Continental biogeographical region of Northern Italy, which is included in Piedmont and Lombardy on the left hydrographic side of the River Po. The goal of this study was to assess the main ecological drivers, i.e. the most important ecological factors, including pressures and threats, that shape negatively ecosystem dynamics, hence affecting conservation targets, and finally to suggest actions for counteracting them. Analyses were done at different scales, through bibliographic researches and site-specific data processing. As a result, we identified groups of ecological drivers, among which three were recognized as prevalent: a) the anthropic alteration of water levels; and b) the natural ecological succession in combination to c) the abandonment of traditional land use practices. The last two main ecological drivers were regarded as those to be counteracted by removing biomass (through digging, mowing, fire), because they may produce cascading effects and work against all the other ecological drivers. However, it is necessary to define a new reference framework based on pointing out conservation priorities at large scale (regional or supra-regional) and conservation actions at local scale, both focused on adaptive management.] [Article in Italian]

One of the key principles for modeling future impacts of anthropogenic and climate changes on vegetation is to identify clear patterns and trends between plant functional traits and ecological drivers. The global spectrum of plant form and function outlines the major axes of variation and coordination among plant traits. We hypothesized that inter-specific plant trait variation at the regional scale should match axes of plant adaptation highlighted by the global spectrum, and that plant trait–environmental associations should be evident over ranges of environmental indicators corresponding to key drivers of future climate and land use changes in Southern Europe. To test our hypotheses, we analyzed a sample of 1095 plant species from Northern Italy, also characteristic of Southern European vegetation. We analyzed trends for four plant traits (canopy height, leaf area, specific leaf area, leaf nitrogen content) along meso- (temperature, continentality) and micro-climatic (light) ranges, as well as along soil ranges (moisture, reaction and nutrient content), by means of Landolt’s environmental indicators. At the regional scale, the inter-specific variation of mean plant traits over ranges of environmental indicators confirmed the main axes of plant adaptation emphasized by the plant global spectrum. Leaf area and specific leaf area showed the largest sensitivity over ranges of all environmental indicators, while canopy heights were the most responsive to temperature values. Temperature, light conditions and nutrients were associated with clear effects on plant traits, underlining that responses to changes in land use and increased soil nutrient loading (sudden and abrupt changes) could trigger and strengthen responses to climate alteration (gradual changes). Scenarios for the next few decades in Southern Europe indicate increased temperature, nutrient availability and forest coverage that, according to our findings, will favor more ‘acquisitive and fast growing’ plants, also represented by subtropical invasive species.

Paspalum thunbergii, a weedy species native to E Asia, is reported for the first time from W Europe. In Italy a naturalized population was detected in 2014 in a heathland in Boscaccio (Lentate sul Seveso; Monza and Brianza province, Lombardia region). A subsequent revision of local herbaria revealed the existence of a second population, also in Lombardia, discovered in Mortara (Pavia province) in 2011 and now confirmed. The taxonomy and nomenclature of this species are briefly discussed, as are its ecology and habitat preferences. An original line drawing and photographs of the species and its habitat are provided. An updated identification key for the species of Paspalum in Europe is also presented. Citation: Verloove F., Brusa G. & Ardenghi N. M. G. 2016: Studies in the genus Paspalum (Paniceae, Poaceae) in Europe: 3. Paspalum thunbergii, a new naturalized neophyte in W Europe. — Willdenowia 46: 137–143. doi: http://dx.doi.org/10.3372/wi.46.46111 Version of record first published online on 1 A...

The Large Binocular Telescope has two adaptive secondary mirrors (ASMs). Each of these feed four focal stations, three of which are equipped with wavefront sensors (WFS) to provide the signal for adaptive optics (AO) correction. These are (1) FLAO - the on-axis natural guide star system feeding the two LUCI NIR imagers/spectrographs, (2) ARGOS - the ground-layer adaptive optics laser-guide star system, which shares the same port as FLAO, (3) LBTI - the 2-11 micron Fizeau/Nulling interferometer, and (4) Linc-Nirvana - the MCAO system. In this paper, we report on the current status of the AO facilities, FLAO, ARGOS, and the ASMs as well as the (1) detector and performance upgrades to FLAO and LBTI wavefront sensors, i.e. the SOUL project, and (2) improvements to the ASMs’ electronics. We also present improvements to the FLAO operation and checkout procedures.

The present paper describes a procedure for mapping the distribution of Natura 2000 terrestrial habitats (Habitats Directive 92/43/EEC) at the regional scale (Lombardy, Northern Italy) by means of open-source software (QGIS and R). The habitat map within Natura 2000 sites was used for modelling the regional distribution of three selected habitats, by applying classification trees on freely available and fine-scale resolution environmental layers. Land use and forest type maps were combined to refine the regional distribution of selected habitats. The statistical validation showed a fairly substantial overall accuracy of predicted habitat distribution, which was used to determine the regional extent of the habitats and to evaluate the regional effectiveness of Natura 2000 network. We provide an easy and inexpensive procedure, replicable in other contexts in which just basic information on Natura 2000 terrestrial habitats are available, and usable for habitats monitoring according to the Habitats Directive.

Summary 1. Three main directions of adaptive specialization are evident in the world flora, reflecting fundamental trade-offs between economics (conservative vs. acquisitive investment of resources) and size. The current method of ordinating plants according to these trade-offs, CSR classification, cannot be applied to the woody species that dominate many terrestrial ecosystems. 2. We aimed to produce a novel CSR classification method applicable to vascular plants in general. 3. Principal components analysis (PCA) of variation in a range of plant traits for 678 angiosperm, gymnosperm and pteridophyte species was used to determine the limits to multivariate space occupied by functionally diverse species. From this calibration, correlations between PCA axes and values of leaf dry matter content (LDMC; as an index of conservatism in life history), specific leaf area (SLA; indicative of acquisitive economics) and leaf area (LA; photosynthetic organ size) were used to produce predictor regressions from which target species could be compared against the multivariate space. A spreadsheet was developed that returned ternary coordinates and tertiary CSR strategies for target subjects based on LA, LDMC and SLA values. 4. The method allowed classification of target species within a triangular space corresponding to Grime’s theoretical CSR triangle and was sufficiently precise to distinguish strategies between species within genera and within populations of species. It was also largely in agreement with previous methods of CSR classification for herbaceous species. 5. Rapid CSR classification of woody and herbaceous vascular plants is now possible, potentially allowing primary plant functional types and ecosystem processes to be investigated over landscape scales.

Agraïments: The study has been supported by the TRY initiative on plant traits (www.try-db.org). The TRY initiative and database is hosted, developed and maintained by J. Kattge and G. Bönisch (Max-Planck-Institute for Biogeochemistry, Jena, Germany). TRY is/has been supported by DIVERSITAS, IGBP, the Global Land Project, the UK Natural Environment Research Council (NERC) through its program QUEST (Quantifying and Understanding the Earth System), the French Foundation for Biodiversity Research (FRB), and GIS "Climat, Environnement et Société" France. We thank Daniel Laughlin, Frédérique Louault, Belinda Medlyn, Julie Messier, Juli Pausas and Ian Wright for contributing data. The authors declare no conflict of interest. 1. Competitor, stress-tolerator, ruderal (CSR) theory is a prominent plant functional strategy scheme previously applied to local floras. Globally, the wide geographic and phylogenetic coverage of available values of leaf area (LA), leaf dry matter content (LDMC) and specific leaf area (SLA) (representing, respectively, interspecific variation in plant size and conservative vs. acquisitive resource economics) promises the general application of CSR strategies across biomes, including the tropical forests hosting a large proportion of Earth's diversity. - 2. We used trait variation for 3068 tracheophytes (representing 198 families, six continents and 14 biomes) to create a globally calibrated CSR strategy calculator tool and investigate strategy-environment relationships across biomes world-wide. - 3. Due to disparity in trait availability globally, co-inertia analysis was used to check correspondence between a 'wide geographic coverage, few traits' data set and a 'restricted coverage, many traits' subset of 371 species for which 14 whole-plant, flowering, seed and leaf traits (including leaf nitrogen content) were available. CSR strategy/environment relationships within biomes were investigated using fourth-corner and RLQ analyses to determine strategy/climate specializations. - 4. Strong, significant concordance (RV = 0·597; P < 0·0001) was evident between the 14 trait multivariate space and when only LA, LDMC and SLA were used. - 5. Biomes such as tropical moist broadleaf forests exhibited strategy convergence (i.e. clustered around a CS/CSR median; C:S:R = 43:42:15%), with CS-selection associated with warm, stable situations (lesser temperature seasonality), with greater annual precipitation and potential evapotranspiration. Other biomes were characterized by strategy divergence: for example, deserts varied between xeromorphic perennials such as Larrea divaricata, classified as S-selected (C:S:R = 1:99:0%) and broadly R-selected annual herbs (e.g. Claytonia perfoliata; R/CR-selected; C:S:R = 21:0:79%). Strategy convergence was evident for several growth habits (e.g. trees) but not others (forbs). - 6. The CSR strategies of vascular plants can now be compared quantitatively within and between biomes at the global scale. Through known linkages between underlying leaf traits and growth rates, herbivory and decomposition rates, this method and the strategy-environment relationships it elucidates will help to predict which kinds of species may assemble in response to changes in biogeochemical cycles, climate and land use.

The goal for the adaptive optics systems at the Large Binocular Telescope Observatory (LBTO) is for them to operate fully automatically, without the need for an AO Scientist, and to be run by the observers and/or the telescope operator. This has been built into their design. Initially, the AO systems would close the loop using optimal parameters based on the observing conditions and guide star brightness, without adapting to changing conditions. We present the current status of AO operations as well as recent updates that improve the operational efficiency and minimize downtime. Onsky efficiency and performance will also be presented, along with calibrations required for AO closed loop operation.

Vertical profiles of the atmospheric optical turbulence strength and velocity is of critical importance for simulating, designing, and operating the next generation of instruments for the European Extremely Large Telescope. Many of these instruments are already well into the design phase meaning these profies are required immediately to ensure they are optimised for the unique conditions likely to be observed. Stereo-SCIDAR is a generalised SCIDAR instrument which is used to characterise the profile of the atmospheric optical turbulence strength and wind velocity using triangulation between two optical binary stars. Stereo-SCIDAR has demonstrated the capability to resolve turbulent layers with the required vertical resolution to support wide-field ELT instrument designs. These high resolution atmospheric parameters are critical for design studies and statistical evaluation of on-sky performance under real conditions. Here we report on the new Stereo-SCIDAR instrument installed on one of the Auxillary Telescope ports of the Very Large Telescope array at Cerro Paranal. Paranal is located approximately 20 km from Cerro Armazones, the site of the E-ELT. Although the surface layer of the turbulence will be different for the two sites due to local geography, the high-altitude resolution profiles of the free atmosphere from this instrument will be the most accurate available for the E-ELT site. In addition, these unbiased and independent profiles are also used to further characterise the site of the VLT. This enables instrument performance calibration, optimisation and data analysis of, for example, the ESO Adaptive Optics facility and the Next Generation Transit Survey. It will also be used to validate atmospheric models for turbulence forecasting. We show early results from the commissioning and address future implications of the results.

The Large Binocular Telescope Interferometer (LBTI) is a versatile instrument designed for high-angular resolution and high-contrast infrared imaging (1.5-13 microns). In this paper, we focus on the mid-infrared (8-13 microns) nulling mode and present its theory of operation, data reduction, and on-sky performance as of the end of the commissioning phase in March 2015. With an interferometric baseline of 14.4 meters, the LBTI nuller is specifically tuned to resolve the habitable zone of nearby main-sequence stars, where warm exozodiacal dust emission peaks. Measuring the exozodi luminosity function of nearby main-sequence stars is a key milestone to prepare for future exoEarth direct imaging instruments. Thanks to recent progress in wavefront control and phase stabilization, as well as in data reduction techniques, the LBTI demonstrated in February 2015 a calibrated null accuracy of 0.05% over a three-hour long observing sequence on the bright nearby A3V star beta Leo. This is equivalent to an exozodiacal disk density of 15 to 30 zodi for a Sun-like star located at 10pc, depending on the adopted disk model. This result sets a new record for high-contrast mid-infrared interferometric imaging and opens a new window on the study of planetary systems., 17 pages, 18 figures (resubmitted to ApJ with referee's comments)

Species-rich meadow and pasture habitats are recognised by the European Union Habitats Directive as targets for biodiversity conservation. High species richness is hypothesised to be associated with diversity in plant functional traits and life-history strategies, which are potentially restricted in situations of extremely high and low biomass production. However, variability in functional traits has yet to be investigated across a broad biomass range in nature. We measured variability in a range of functional traits and Grime's competitor, stress-tolerator, ruderal (CSR) strategies for species comprising lowland meadows, subalpine pastures, abandoned grassland and field margins at sites in northern Italy, alongside peak above-ground biomass. The factor most highly and positively correlated with species richness was strategy richness (the number of CSR strategies; Pearson's r = 0.864, P

We present nulling interferometric observations of six nearby main-sequence stars (α CrB, α Lyr, β Leo, γ Ser, Eri, and ζ Lep). None of the stars show evidence for a positive detection of warm debris in the habitable zone of the systems. Using a scaled up model of solar zodiacal emission, the 3σ upper limits on dust density range from 220 to 104 Zody (1 Zody = the density of our own solar zodiacal cloud) depending on the particular star, corresponding to mass limits of 10–7 to 10–5 M ⊕ of micron-sized dust. These limits contrast with the presence of dust at greater separations from the star, implying a clearing in dust in the inner system. This suggests that the inner circumstellar environment around nearby intermediate-mass main-sequence stars more than several tens of millions of years old are generally cleared of dusty debris. Finally, the well studied nature of the debris disks around Vega, Eridani, and ζ Leporis allows us to place these 10 μm nulling observations in the context of previous studies to determine the physical processes responsible for shaping the debris disk in these particular systems.

We present the results of 10 micron nulling interferometric observations of 13 Herbig Ae stars using the Magellan I (Baade) and the MMT 6.5 m telescopes. A portion of the observations was completed with the adaptive secondary at the MMT. We have conclusively spatially resolved 3 of the 13 stars, HD 100546, AB Aur, and HD 179218, the latter two recently resolved using adaptive optics in combination with nulling interferometry. For the resolved objects we find that the 10 $\mu$m emitting regions have a spatial extent of 15-30 AU in diameter. We also have some evidence for resolved emission surrounding an additional 2 stars (V892 Tau and R CrA). For those objects in our study with mid-IR SEDs classifications from Meeus et al. (2001), we find that the Group I objects (those with constant to increasing mid-IR flux) are more likely to be resolved, within our limited sample. This trend is evident in correlations in the inferred disk sizes vs. the sub-millimeter SED slope and disk size vs. fractional infrared luminosity of the systems. We explore the spatial distribution and orientation of the warm dust in the resolved systems and constrain physical models which are consistent with their observational signatures., Comment: 28 pages, including 3 figures, Accepted for publication in The Astrophysical Journal

We report on the first nulling interferometric observations with the Large Binocular Telescope Interferometer (LBTI), resolving the N' band (9.81 - 12.41 um) emission around the nearby main-sequence star eta Crv (F2V, 1-2 Gyr). The measured source null depth amounts to 4.40% +/- 0.35% over a field-of-view of 140 mas in radius (~2.6\,AU at the distance of eta Corvi) and shows no significant variation over 35{\deg} of sky rotation. This relatively low null is unexpected given the total disk to star flux ratio measured by Spitzer/IRS (~23% across the N' band), suggesting that a significant fraction of the dust lies within the central nulled response of the LBTI (79 mas or 1.4 AU). Modeling of the warm disk shows that it cannot resemble a scaled version of the Solar zodiacal cloud, unless it is almost perpendicular to the outer disk imaged by Herschel. It is more likely that the inner and outer disks are coplanar and the warm dust is located at a distance of 0.5-1.0 AU, significantly closer than previously predicted by models of the IRS spectrum (~3 AU). The predicted disk sizes can be reconciled if the warm disk is not centrosymmetric, or if the dust particles are dominated by very small grains. Both possibilities hint that a recent collision has produced much of the dust. Finally, we discuss the implications for the presence of dust at the distance where the insolation is the same as Earth's (2.3 AU)., Comment: 9 pages, 6 figures, accepted for publication in ApJ

The Large Binocular Telescope Interferometer is a NASA-funded nulling and imaging instrument designed to coherently combine the two 8.4-m primary mirrors of the LBT for high-sensitivity, high-contrast, and high-resolution infrared imaging (1.5-13 um). PHASECam is LBTI's near-infrared camera used to measure tip-tilt and phase variations between the two AO-corrected apertures and provide high-angular resolution observations. We report on the status of the system and describe its on-sky performance measured during the first semester of 2014. With a spatial resolution equivalent to that of a 22.8-meter telescope and the light-gathering power of single 11.8-meter mirror, the co-phased LBT can be considered to be a forerunner of the next-generation extremely large telescopes (ELT)., Comment: 8 pages, 5 figures, SPIE Conference proceedings

We present the results of mid-infrared nulling interferometric observations of the main-sequence star alpha Lyr (Vega) using the 6.5 m MMT with its adaptive secondary mirror. From the observations at 10.6 microns, we find that there is no resolved emission from the circumstellar environment (at separations greater than 0.8 AU) above 2.1% (3 sigma limit) of the level of the stellar photospheric emission. Thus, we are able to place an upper limit on the density of dust in the inner system of 650 times that of our own solar system's zodiacal cloud. This limit is roughly 2.8 times better than those determined with photometric excess observations such as those by IRAS. Comparison with far-infrared observations by IRAS shows that the density of warm dust in the inner system (< 30 AU) is significantly lower than cold dust at larger separations. We consider two scenarios for grain removal, the sublimation of ice grains and the presence of a planetary mass "sweeper." We find that if sublimation of ice grains is the only removal process, a large fraction (> 80%) of the material in the outer system is ice., 11 pages, 1 figure, Accepted to The Astrophysical Journal Letters

We present the first scientific images obtained with a deformable secondary mirror adaptive optics (AO) system. We utilized the 6.5 m Multiple Mirror Telescope adaptive optics system to produce high-resolution (FWHM ¼ 0>07) near-infrared (1.6 lm) images of the young (� 1 Myr) Orion Trapezium � 1 Ori cluster members. A combination of high spatial resolution and high signal-to-noise ratio allowed the positions of these stars to be measured to within � 0>003 accuracies. We also present slightly lower resolution (FWHM � 0>085) images from Gemini with the Hokupa‘a AO system as well. Including previous speckle data from Weigelt et al., we analyze a 6 yr baseline of high-resolution observations of this cluster. Over this baseline we are sensitive to relative proper motions of only � 0>002 yr � 1 (4.2 km s � 1 at 450 pc). At such sensitivities we detect orbital motion in the very tight � 1 Ori B2-B3 (52 AU separation) and � 1 Ori A1-A2 (94 AU separation) systems. The relative velocity in the � 1 Ori B2-B3 system is 4:2 � 2: 1k m s � 1 . We observe 16:5 � 5: 7k m s � 1 of relative motion in the � 1 Ori A1-A2 system. These velocities are consistent with those independently observed by Schertl et al. with speckle interferometry, giving us confidence that these very small (� 0>002 yr � 1 ) orbital motions are real. All five members of the � 1 Ori B system appear likely gravitationally bound (B2-B3 is moving at � 1.4 km s � 1 in the plane of the sky with respect to B1, where Vesc � 6k m s � 1 for the B group). The very lowest mass member of the � 1 Ori B system (B4) has K 0 � 11:66 and an estimated mass of � 0.2 M� . Very little motion (4 � 15 km s � 1 ) of B4 was detected with respect to B1 or B2; hence, B4 is possibly part of the � 1 Ori B group. We suspect that if this very low mass member is physically associated, it most likely is in an unstable (nonhierarchical) orbital position and will soon be ejected from the group. The � 1 Ori B system appears to be a good example of a star formation ‘‘ minicluster,’’ which may eject the lowest mass members of the cluster in the near future. This ‘‘ ejection ’’ process could play a major role in the formation of low-mass stars and brown dwarfs. Subject headings: binaries: general — instrumentation: adaptive optics — stars: evolution — stars: formation — stars: low-mass, brown dwarfs On-line material: color figures

We utilized the MMT's unique deformable secondary adaptive optics system to produce high-resolution (FWHM=0.3"), very high Strehl mid-infrared (9.8, 11.7 & 18 micron) images of the post-AGB star AC Her. The very high (98+/-2%) Strehls achieved with Mid-IR AO led naturally to an ultra-stable PSF independent of airmass, seeing, or location on the sky. We find no significant difference between AC Her's morphology and our unresolved PSF calibration stars (mu UMa & alpha Her) at 9.8, 11.7, & 18 microns. Our current observations do not confirm any extended Mid-IR structure around AC Her. These observations are in conflict with previously reported Keck (seeing-limited) 11.7 and 18 micron images which suggested the presence of a resolved ~0.6" edge-on circumbinary disk. We conclude that AC Her has no extended Mid-IR structure on scales greater than 0.2" (R

The design of adaptive optics systems is driven by the local characteristics of the atmospheric turbulence. Site characterization campaigns utilizing a variety of atmospheric monitoring equipment provides a statistical description of parameters such integrated seeing, vertical distribution of turbulence strength as well as the coherent time of the turbulence. Modeling work, intended to understand the operation bandwidth of adaptive optics systems make use of Kolmogorov turbulence theory as well as time series of atmospheric parameters obtained from regression analysis based on site characterization data. However, most of the time, even in the more detailed studies, one parameter though important is not measured and monitored with the same attention than the other turbulence parameters, namely, the outer scale of the turbulence. The image quality in large aperture telescopes has been shown to have an important dependence on the instantaneous magnitude of the outer scale of the turbulence. In general terms, the shorter the outer scale of the turbulence, the lower the wavefront variance over the aperture of the imaging system and consequently the higher the image quality. This study focuses in using reconstructed open loop wavefront sensor data observed simultaneously by the two apertures of the Large Binocular Telescope (LBT) to compute and monitor the outer scale of the turbulence.

The Large Binocular Telescope has two adaptive secondary mirrors which are used for regular observing in both seeinglimited mode and for diffraction-limited mode unlike the adaptive secondaries at the MMT and Magellan telescopes which are swapped in for diffraction-limited observing only. The LBTO secondary mirrors have been in routine operation for ~ 4 years for the first and for ~ 2 years for the second. We review the operational history of these units and discuss the various failure modes unique to adaptive secondaries as compared with rigid secondaries for seeing-limited observing and more conventional adaptive optics systems for diffraction-limited observing.

The Large Binocular Telescope with its integrated adaptive optics systems and the LBTI beamcombiner provides a good platform for carrying out coherent imagin across its 22.7 m baseline. The first cameras used with LBTI have focused on infrared wavelengths. We describe a concept, called the LBT Interferometer Visible Extension (LIVE) to carry out coherent imaging with the LBT at visible wavelengths. LIVE will be able to create images of some of the stars with the largest angular diameters, map the surface of solar system moons, and provide detailed imaging of the inner scattered light regions of protoplanetary and transition disks. An initial approach can use the beamcombiner with its existing infrared phase sensor to carry out coherent imaging using frame selection to improve the image quality. Refined and more versatile phase sensing and correction can be implemented in a second stage to enable observations of a wider range of targets. LIVE will work both as a coherent imager, as well as a flexible dual aperture AO imager where simultaneous differential measurements can be made through independent use of each arm. We describe the science case and technical description below. We plan to develop the system with a flexible approach that allows increasingly complex modes of observation to be added once the basic performance is demonstrated.

We describe the different Adaptive Optics systems on the Large Binocular Telescope making use of the adaptive secondary mirrors and different wavefront sensors. System performances will be discussed.

Fallopia japonica succeeds in invading different ecosystems likely because of its huge biomass production. This biomass is characterized by low nutritional quality and low decomposition rates but knowledge on whether these features are correlated to microbial decomposers is still lacking. The aims of this work were: i) to determine litter decomposition rates of native grassland vegetation and F. japonica under different conditions in a year-round experiment; ii) to evaluate litter quality and/or site effect on the decomposition of the invader and native vegetation and iii) to characterize mycoflora isolated from F. japonica and native vegetation litter. The results showed that F. japonica litter decomposes 3–4 times slower than that of native grassland, mainly due to its low N content and consequently high C/N ratio both in leaves and stems. As decomposition proceeds C/N in F. japonica litter decreases to values approaching those of the grassland litter. Site had no effect on the decomposition rates of F. japonica and grassland litter. Total fungal load and composition differed between F. japonica and native litter, and also varied across sites. These results indicate that the successful invasive plant F. japonica affects the structure and functions of the invaded ecosystem through a huge production of low quality, slow-decomposing litter that selects saprotrophic fungi.

The diversity of orchid species in semi-natural calcareous grassland is thought to depend on floral variability. However, differences in primary life-history strategy, or the overall suite of functional traits, could also affect coexistence. Both primary strategy (affecting day-to-day survival) and reproductive traits (representing periodic events) have been hypothesized to contribute to a general mechanism regulating the local persistence and relative abundance of species. We recorded species identity at 8,000 points at the centimetre scale along sixteen 5-m long transects at the Olive Lawn, a xeric sand calcareous grassland near Lecco, Italy. Transects allowed the relative abundance and spatial aggregation of Grime’s competitor, stress-tolerator, ruderal (CSR) strategies to be quantified. Orchid flowering and fruiting phenology was recorded alongside the phenology of graminoid growth. Seven orchid species were present and exhibited a spectrum of strategies spanning two extremes, (1) small early-flowering ruderals (R/CR-selected), and (2) larger-leaved competitors (C/CR) flowering later as dominant graminoids attained maximum height. These orchids, and other subordinate species in the community, exhibited random spatial distributions amongst dominant graminoids that exhibited a high degree of spatial aggregation and similar, but non-identical, stress-tolerator (S) strategies. The reproductive phenology of meadow orchids is an intimate component of their CSR strategies, and appears to promote coexistence by allowing segregation between temporal niches and the exploitation of opportunities between clumps of dominant species. Only for closely related species with identical CSR strategies, such as Ophrys benacensis and Ophrys sphegodes, could specific floral differences alone explain coexistence.

Pseudoleskea artariae Ther. is recorded in three new Italian localities. A distribution map is reported for the Insubrian area (Italian-Swiss border). Morphological, ecological and chorological remarks are also given.

In plant leaves, resource use follows a trade-off between rapid resource capture and conservative storage. This “worldwide leaf economics spectrum” consists of a suite of intercorrelated leaf traits, among which leaf mass per area, LMA, is one of the most fundamental as it indicates the cost of leaf construction and light-interception borne by plants. We conducted a broad-scale analysis of the evolutionary history of LMA across a large dataset of 5401 vascular plant species. The phylogenetic signal in LMA displayed low but significant conservatism, that is, leaf economics tended to be more similar among close relatives than expected by chance alone. Models of trait evolution indicated that LMA evolved under weak stabilizing selection. Moreover, results suggest that different optimal phenotypes evolved among large clades within which extremes tended to be selected against. Conservatism in LMA was strongly related to growth form, as were selection intensity and phenotypic evolutionary rates: woody plants showed higher conservatism in relation to stronger stabilizing selection and lower evolutionary rates compared to herbaceous taxa. The evolutionary history of LMA thus paints different evolutionary trajectories of vascular plant species across clades, revealing the coordination of leaf trait evolution with growth forms in response to varying selection regimes. Fil: Flores, Olivier. Centre d’Ecologie Fonctionnelle et Evolutive; Francia. Université de la Réunion; Francia Fil: Garnier, Eric. Centre d’Ecologie Fonctionnelle et Evolutive; Francia Fil: Wright, Ian J.. Macquarie University. Department of Biological Sciences; Australia Fil: Reich, Peter B.. University of Minnesota. Department of Forest Resources and Institute on the Environment; Estados Unidos. University of Western Sydney. Hawkesbury Institute for the Environment; Australia Fil: Pierce, Simon. University of Milan. Department of Plant Production; Italia Fil: Diaz, Sandra Myrna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Pakeman, Robin J... James Hutton Institute; Reino Unido Fil: Rusch, Graciela M.. Norwegian Institute for Nature Research; Noruega Fil: Bernard Verdier, Maud. Centre d’Ecologie Fonctionnelle et Evolutive; Francia Fil: Testi, Baptiste. Centre d’Ecologie Fonctionnelle et Evolutive; Francia Fil: Bakker, Jan P.. Community and Conservation Ecology Group; Países Bajos Fil: Bekker, Renee M.. Community and Conservation Ecology Group; Países Bajos Fil: Cerabolini, Bruno. Universita degli Studi dell’Insubria; Italia Fil: Ceriani, Roberta. Centro Flora Autoctona; Italia Fil: Cornu, Guillaume. Department Environment and Societies Research Unit Forests and Societies; Francia Fil: Cruz, Pablo. Institut National de la Recherche Agronomique; Francia Fil: Delcamp, Matthieu. Department Environment and Societies Research Unit Forests and Societies; Francia Fil: Dolezal, Jiri. Academy of Sciences of the Czech Republic. Institute of Botany; República Checa Fil: Eriksson, Ove. Stockholm University. Department of Botany; Suecia Fil: Fayolle, Adeline. Department Environment and Societies Research Unit Forests and Societies; Francia Fil: Freitas, Helena. University of Coimbra. Centre for Functional Ecology; Portugal Fil: Golodets, Carly. Faculty of Life Sciences. Department of Molecular Biology and Ecology of Plants; Israel Fil: Gourlet Fleury, Sylvie. Department Environment and Societies Research Unit Forests and Societies; Francia Fil: Hodgson, John. The University. Department of Archaeology; Reino Unido Fil: Brusa, Guido. Universitá degli Studi dell’Insubria; Italia Fil: Kleyer, Michael. Carl von Ossietzky University of Oldenburg. Landscape Ecology Group; Alemania Fil: Kunzmann, Dieter. Carl von Ossietzky University of Oldenburg. Landscape Ecology Group; Alemania Fil: Lavorel, Sandra. Universite Joseph Fourier. Laboratoire d’Ecologie Alpine and Station Alpine Joseph Fourier; Francia Fil: Papanastasis, Vasilios. Aristotle University of Thessaloniki. Laboratory of Rangeland Ecology; Grecia Fil: Perez Harguindeguy, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Vendramini, Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Weiher, Evan. University of Wisconsin Eau Claire. Department of Biology; Estados Unidos

The Large Binocular Telescope (LBT) is unique in that it is currently the only large telescope (2 x 8.4m primary mirrors) with permanently mounted adaptive secondary mirrors (ASMs). These ASMs have been used for regular observing since early 2010 on the right side and since late 2011 on the left side. They are currently regularly used for seeing-limited observing as well as for selective diffraction-limited observing and are required to be fully operational every observing night. By comparison the other telescopes using ASMs, the Multi Mirrot Telescope (MMT) and more recently Magellan, use fixed secondaries of seeing-limited observing and switch in the ASMs for diffraction-limited observing. We will discuss the night-to-night operational requirements for ASMs specifically for seeing-limited but also for diffraction-limited observations based on the LBT experience. These will include preparation procedures for observing (mirror flattening and resting as examples); hardware failure statistics and how to deal with them such as for the actuators; observing protocols for; and current limitations of use due to the ASM technology such as the minimum elevation limit (25 degrees) and the hysteresis of the gravity-vector induced astigmatism. We will also discuss the impact of ASM maintenance and preparation

The software configurable optical test system (SCOTS) is an efficient metrology technology based on reflection deflectometry that uses only an LCD screen and a camera to measure surface slope. The surface slope is determined by triangulations using the coordinates of the display screen, camera and test mirror. We present our recent SCOTS test results concentrated on high dynamic range measurements of low order aberrations. The varying astigmatism in the 91 cm diameter aspheric deformable secondary mirror for the Large Binocular Telescope (LBT) was measured with SCOTS, requiring no null corrector. The SCOTS system was designed on axis with camera and screen aligned on the optical axis of the test mirror with the help of a 6 inch pellicle beam splitter. The on-axis design gives better control of the astigmatism in the test. The high dynamic range of slope provided a measurement of astigmatism with 0.2 μm rms accuracy in the presence of 231 μm peak-to-valley (PV) aspheric departure. The simplicity of the test allowed the measurements to be performed at multiple elevation angles.

The Giant Magellan Telescope is planning to provide adaptive wavefront correction of the low layers (

The Giant Magellan Telescope (GMT) adaptive optics (AO) system will be an integral part of the telescope, providing laser guidestar generation, wavefront sensing, and wavefront correction to every instrument currently planned on the 25.4 m diameter GMT. There will be three first generation AO observing modes: Natural Guidestar, Laser Tomography, and Ground Layer AO. All three will use a segmented adaptive secondary mirror to deliver a corrected beam directly to the instruments. The Natural Guidestar mode will provide extreme AO performance, with a total wavefront error less than 185 nm RMS using bright guidestars. The Laser Tomography mode uses 6 lasers and a single off-axis natural guidestar to deliver better than 290 nm RMS wavefront error at the science target, over 50% of the sky at the galactic pole. The Ground Layer mode uses 4 natural guidestars on the periphery of the science field to tomographically reconstruct and correct the ground layer AO turbulence, improving the image quality for wide-field instruments. A phasing system maintains the relative alignment of the primary and secondary segments using edge sensors and continuous feedback from an off-axis guidestar. We describe the AO system preliminary design, predicted performance, and the remaining technical challenges as we move towards the start of construction.

This paper summarizes the activities and the principal results achieved during the commissioning of the two Natural Guide Star (NGS) AO systems called FLAO#1 & 2 installed at the bent Gregorian focal stations of the 2x8.4m Large Binocular Telescope (LBT). The commissioning activities of FLAO#1 took place in the period February 2010 - October 2011, while FLAO#2 commissioning started in December 2011 and should be completed by November 2012. The main results of the commissioning campaign are presented in terms of the H-band Strehl Ratio values achieved under different observing conditions. We will also describe the automatic procedures to configure and set-up the FLAO systems, and in particular the modal gain optimization procedure, which has been proven to be a very important one in achieving the nominal performance. Finally, some of the results achieved in two science runs using the near infra-red camera PISCES are briefly highlighted. © 2012 SPIE.

ARGOS the Advanced Rayleigh guided Ground layer adaptive Optics System for the LBT (Large Binocular Telescope) is built by a German-Italian-American consortium. It will be a seeing reducer correcting the turbulence in the lower atmosphere over a field of 2' radius. In such way we expect to improve the spatial resolution over the seeing of about a factor of two and more and to increase the throughput for spectroscopy accordingly. In its initial implementation, ARGOS will feed the two near-infrared spectrograph and imager - LUCI I and LUCI II. The system consist of six Rayleigh lasers - three per eye of the LBT. The lasers are launched from the back of the adaptive secondary mirror of the LBT. ARGOS has one wavefront sensor unit per primary mirror of the LBT, each of the units with three Shack-Hartmann sensors, which are imaged on one detector. In 2010 and 2011, we already mounted parts of the instrument at the telescope to provide an environment for the main sub-systems. The commissioning of the instrument will start in 2012 in a staged approach. We will give an overview of ARGOS and its goals and report about the status and new challenges we encountered during the building phase. Finally we will give an outlook of the upcoming work, how we will operate it and further possibilities the system enables by design.

The Adaptive Optics System at the Large Binocular Telescope Observatory consists of two Adaptive Secondary (ASM) mirrors and two Pyramid Wavefront sensors. The first ASM/Pyramid pair has been commissioned and is being used for science operation using the NIR camera PISCES on the right side of the binocular telescope. The left side ASM/Pyramid system is currently being commissioned, with completion scheduled for the Fall of 2012. We will discuss the operation of the first Adaptive Optics System at the LBT Observatory including interactions of the AO system with the telescope and its TCS, observational modes, user interfaces, observational scripting language, time requirement for closed loop and offsets and observing efficiency.

The Large Binocular Telescope (LBT) is a unique telescope featuring two co-mounted optical trains with 8.4m primary mirrors. The telescope Adaptive Optics (AO) system uses two innovative key components, namely an adaptive secondary mirror with 672 actuators and a high-order pyramid wave-front sensor. During the on-sky commissioning such a system reached performances never achieved before on large ground-based optical telescopes. Images with 40mas resolution and Strehl Ratios higher than 80% have been acquired in H band (1.6 micron). Such images showed a contrast as high as 10e-4. Based on these results, we compare the performances offered by a Natural Guide Star (NGS) system upgraded with the state-of-the-art technology and those delivered by existing Laser Guide Star (LGS) systems. The comparison, in terms of sky coverage and performances, suggests rethinking the current role ascribed to NGS and LGS in the next generation of AO systems for the 8-10 meter class telescopes and Extremely Large Telescopes (ELTs)., 10 pages, 9 figures, Preented at SSPIE Optics + Photonics 2011, San Diego 20-25 August 2011