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Biomonitoring plays a crucial role in the assessment of air quality, as it allows to estimate the presence of pollutants, by measuring deviations from normality of the components of an ecosystem. Lichens are among the organisms most commonly used as bioindicators. The present study deals with the classification of lichen taxa from images, by means of a machine learning process based on patch classification. A given image is divided in non-overlapping patches, and each of them undergoes feature extraction and classification, eventually being associated to a category. Three different methods for extracting patch descriptors are investigated: (i) handcrafted descriptors based on classical feature extractor algorithms, (ii) convolutional neural networks employed as feature extractors, and (iii) scattering networks, which combine wavelet convolutions and nonlinear operators. For each of these methods, the descriptors are used as inputs for a classification algorithm. The whole process is evaluated in terms of classification accuracy, empirically determining the most appropriate parameters for the different models implemented. By using the dataset of lichens of this study, best results (∼ 0.89 accuracy) are obtained with a specific handcrafted descriptor (dense SIFT), thus providing insights on the kind of representation which is most suitable for the task.

The amount of available Citizen Science data has increased significantly in the last two decades and has been used in several biogeographic studies as well. Citizen Science data are mostly collected through digital platforms, and especially mobile Apps. While the adoption of novel Information and Communications Technology (ICT) approaches potentially allow for a wider participation, recent studies have highlighted that the ability of making an intensive use of smartphones and mobile apps could decrease with users’ age. At the same time, data quality and commitment of volunteers in citizen science activities often increases with the age of volunteers. During the CSMON-LIFE (Citizen Science MONitoring) project volunteers provided their year of birth, thus allowing for inferences on the relation between age and data quality and retention rate. In this manuscript, a further investigation is carried out for understanding the potential effect of the digital gap that exists especially between young adults and old adults on participation to citizen science activities. In the case of CSMON-LIFE, older age classes are under-represented, if compared to the overall Italian population. While the difference cannot be with absolute certainty ascribed to one factor alone, it can be hypothesized that a relevant contribution to the limited participation of old adults could be due to the intensive adoption of mobile Apps. Furthermore, it seems that choice of mobile devices among volunteers is quite different from that made by the average population based on availability in the Italian market, possibly evidencing an overall higher education of citizen scientists. Therefore, it can be said that digital divide can have a negative effect on the participation of volunteers belonging to the older age classes, even if this effect will probably slowly disappear in the future.

Environmental sustainability of viticulture is negatively affected by prolonged droughts. In limestone dominated regions, there is limited knowledge on grapevine water status and on methods for accurate evaluation of actual water demand, necessary to appropriately manage irrigation. During a dry vintage, we monitored plant and soil water relations in old and young vines of Istrian Malvasia on Karst red soil. The vineyard with young vines was additionally subdivided into two areas, based on their soil type, 1) karst silty-clay loam, and 2) mixture of crushed rocks and karst silty-clay loam (stony soil). Seasonal changes in exploited water resources were estimated via analysis of oxygen isotope composition (δ18O) of rainfall, deep soil water, and xylem sap. We hypothesized that plants are able to thrive during drought thanks to the water stored in deep soil layers, while they rely less on superficial soil horizons. Our results show that vines growing on karstic substrates have deep roots securing the use of stable water sources during summer, with consequent favourable plant water status. In fact, both young and mature vines approached the threshold of severe water stress, but never surpassed it, as midday leaf water potentials were >−1.3 MPa in all study sites. Vines roots showed flexible water uptake, i.e. the ability to absorb water from deep or shallow soil horizons during drought and after late-summer thunderstorms, which was particularly evident in vines growing on the stony soil. In fact, precipitations of 20 mm were enough for plant water status recovery, due to fast infiltration. On the other hand, at least 50 mm of rainfall were necessary to induce water status recovery in more compact soil (karst silty-clay loam). Our findings provide new knowledge on the rooting depth and water needs of vines growing on shallow soils overlying fractured limestone bedrock.

An ecological biogeographical perspective provides an understanding of the factors that shape the geographical distribution of organisms, their biodiversity and ecological speciation. Focusing on members of the lichen genus Solenopsora, which are strongly linked to a Mediterranean-type climate, we aimed to depict their environmental niches in the Apennine Peninsula. This area represents their ecological optima, as well as the biogeographical centre of distribution. On the basis of occurrences of Solenopsora congeners, we identified the key ecological factors that shape their environmental niches. Applying an ensemble approach, which merges the results of Random Forest, GLM and MaxEnt algorithms, suitability maps were developed. These are mainly influenced by geological substratum, temperature and precipitation. Occurrence of Solenopsora taxa seems to be mainly governed by low variability in diurnal temperature and tolerance to dryness, with precipitation in the range of 0–20 mm in the driest month and a minimum temperature of >5 °C in the coldest month. The sensitivity to diurnal temperature, an important indicator for climate change, suggests that the taxa confined to Mediterranean bioclimatic types (i.e. Solenopsora grisea, S. marina, S. olivacea subsp. olbiensis and S. olivacea subsp. olivacea) might be good indicators of climatic stability. The geological substratum was a strong limiting factor and separated the taxa into three groups: those growing on calcareous, siliceous and ultramafic substrata. Limited co-occurrence of species confined to one of the three categories suggests that the level of niche differentiation is on a microhabitat level. Accounting for ecological requirements, the taxa differ in their tolerance to sub-optimal conditions. The ecological niches of a sister subspecies pair with different reproduction strategies, fertile S. olivacea subsp. olivacea and sorediate S. olivacea subsp. olbiensis, overlap strongly. However, habitat suitability for S. olivacea subsp. olbiensis is greater in areas with higher precipitation in the driest month, whereas S. olivacea subsp. olivacea is more restricted to warmer and drier areas. We also report new regional records for Italy and the first records of S. cesatii in Serbia and Ukraine, and of S. liparina in Serbia.

The Mediterranean is one of the major biodiversity hotspots of the world. It has been identified as the “core” of the speciation process for many groups of organisms. It hosts an impressive number of species, many of which are classified as endangered taxa. Climate change in such a diverse context could heavily influence community composition, reducing ecosystems resistance and resilience. This study aims at depicting the distribution of nine orchid species in the island of Sardinia (Italy), and at forecasting their future distribution in consequence of climate change. The models were produced by following an “ensemble” approach. We analysed present and future (2070) niche for the nine species, using Land Use and Soil Type, as well as 8 bioclimatic variables as predictors, selected because of their influence on the fitness of these orchids. Climate change in the next years, at Mediterranean latitudes, is predicted to results mainly in an increase of temperature and a decrease of precipitation. In 2070, the general trend for almost all modelled taxa is the widening of the suitable areas. However, not always the newly gained areas have high probability of presence. A correct interpretation of environmental changes is needed for developing effective conservation strategies.

Volunteers’ contribution to research is growing, especially since the beginning of the 21st century. Given the constant increase of Citizen Science initiatives, recruiting strategies have to be planned properly. Retention is pivotal as well, especially when time is invested in volunteers’ training. However, practically no follow-up data are available on retention after major Citizen Science initiatives. CSMON-LIFE (Citizen Science MONitoring) was a 42-month project (2014–2017) funded by the European Commission in the framework of the LIFE+ programme (LIFE13 ENV/IT/842). It aimed at increasing awareness on Citizen Science among citizens, researchers, and decision makers in Italy. During CSMON-LIFE, recruitment was based on extensive awareness raising actions on different media. In total, 5558 volunteers were engaged in different field activities during the project and its follow-up. They gathered a total of 30062 geo-referenced observations, each with an image of the reported organism. Their activities were organized in campaigns, each devoted to a different topic. This study aims at investigating volunteers’ performance and retention in the funded period of CSMON-LIFE (December 2014–November 2017) and in its after-LIFE follow-up period (December 2017–November 2020), for a total of 72 months.

Work is in progress for the completion of a computer-aided key to all lichens known to occur in Italy, which will be freely available online, and as a free application for mobile devices. A first example, concerning the lichens of Northern Italy (2.339 infrageneric taxa), is already available online for testing. A computer-generated but manually edited dichotomous key is invoked for all species previously filtered via a multi-entry interface, where several selected characters can be specified in a single step. To optimize the two query interfaces, two different datasets are used, one for the dichotomous, the other for the multi-entry interface.

Digital data concerning the flora of Italy are largely fragmented among different resources hosted on different platforms, and often with different data standards, which are neither connected by a common access point, nor by web services, thus constituting a relevant obstacle to data access and usage. Taxonomic incongruences add a further complication. This paper describes “FlorItaly”, an online information system which allows to access and query updated information on the checklist of the flora of Italy, aiming at becoming an aggregator for Italian botanical resources. “FlorItaly” was developed in a collaborative effort by more than 50 taxonomists, with the support of the Italian Botanical Society, and of Project “Dryades” (University of Trieste), to provide a better and reliable organization of botanical knowledge in Italy, as well as a relevant simplification for data retrieval, and a further stimulus towards a more collaborative approach in botanical research.

This note adds new occurrence records of the hemipteran alien species Zelus renardii (Kolenati, 1856) in Italy by citizens, entomologists and photographers. This species was recorded for first time in Rome in 2013., Fragmenta Entomologica, Vol. 50 No. 1 (2018)

A citizen science initiative was launched in the province of Trieste, aimed at mapping the distribution of Ailanthus altissima, Ambrosia artemisiifolia and Senecio inaequidens. The reliability of citizen data was tested against control data obtained by trained personnel with a stratified random sampling. In spite of the lack of a strict sampling strategy, citizen data were highly correlated with control data. This was mainly due to: 1) the easy identification of the species and 2) the instructions given to citizens for selecting their observation areas and for avoiding duplicate records. The three species tend to be most frequent in disturbed areas; Ailanthus is highly concentrated in the urban area, Senecio is widely distributed but avoids the city centre, with the highest frequency in the industrial area and along the railways, Ambrosia has a similar pattern, but is most frequent in areas with calcareous substrata. The interpretation of the distribution patterns in terms of land use and ecological factors proved to be quite easy when the three species are considered together (higher frequency in disturbed areas), less so when they are considered separately, most probably because of historical and sociological factors, such as incomplete migration into the survey area, and "gentrification effects".

In this contribution, new data concerning algae, bryophytes, fungi, and lichens of the Italian flora are presented. It includes new records and confirmations for the algae genusChara, the bryophyte generaHomalia,Mannia, andTortella, the fungal generaCortinarius,Russula, andStereum, and the lichen generaCetrelia,Cladonia,Enterographa,Graphis,Lecanora,Lepraria,Multiclavula,Mycomicrothelia,Parmelia,Peltigera,Pleopsidium,Psora,Scytinium,Umbilicaria, andRhizocarpon.

Ongoing climate change is apparently increasing tree mortality rates, and understanding mechanisms of drought-induced tree decline can improve mortality projections. Differential drought impact on conspecific individuals within a population has been reported, but no clear mechanistic explanation for this pattern has emerged. Following a severe drought (summer 2012), we monitored over a 3-year period healthy (H) and declining (D) Pinus nigra trees co-occurring in a karstic woodland to highlight eventual individual-specific physiological differences underlying differential canopy dieback. We investigated differences in water and carbon metabolism, and xylem anatomy as a function of crown health status, as well as eventual genotypic basis of contrasting drought responses. H and D trees exploited the same water pools and relied on similar hydraulic strategies to cope with drought stress. Genetic analyses did not highlight differences between groups in terms of geographical provenance. Hydraulic and anatomical analyses showed conflicting results. The hydraulic tracheid diameter and theoretical hydraulic conductivity were similar, but D trees were characterized by lower water transport efficiency, greater vulnerability to xylem conduit implosion and reduced carbohydrate stores. Our results suggest that extreme drought events can have different impacts on conspecific individuals, with differential vulnerability to xylem embolism likely playing a major role in setting the fate of trees under climate change.

Despite that congruence across taxa has been proved as an effective tool to provide insights into the processes structuring the spatial distribution of taxonomic groups and is useful for conservation purposes, only a few studies on cross-taxon congruence focused on freshwater ecosystems and on the relations among vascular plants and lichens. We hypothesized here that, since vascular plants could be good surrogates of lichens in these ecosystems, it would be possible to assess the overall biodiversity of riparian habitats using plant data only. In this frame, we explored the relationship between (a) species richness and (b) community composition of plants and lichens in a wetland area located in central Italy to (i) assess whether vascular plants are good surrogates of lichens and (ii) to test the congruence of patterns of species richness and composition among plants and lichens along an ecological gradient. The general performance of plant species richness per se, as a biodiversity surrogate of lichens, had poor results. Nonetheless, the congruence in compositional patterns between lichens and vascular plants varied across habitats and was influenced by the characteristics of the vegetation. In general, we discussed how the strength of the studied relationships could be influenced by characteristics of the data (presence/absence vs. abundance), by the spatial scale, and by the features of the habitats. Overall, our data confirm that the more diverse and structurally complex the vegetation is, the more diverse are the lichen communities it hosts.

Extreme summer droughts induced differential impacts in a population of Pinus nigra trees. We analyzed eventual physiological differences between desiccated and healthy trees. Desiccated trees were more vulnerable to drought-induced xylem embolism, and were also suffering from depletion of carbohydrate reserves. Our data suggest that genotypic or phenotypic intraspecific variability can play fundamental roles in defining individual drought responses/impacts, dictating the fate of single trees under global-change-type droughts., Ongoing climate change is apparently increasing tree mortality rates, and understanding mechanisms of drought-induced tree decline can improve mortality projections. Differential drought impact on conspecific individuals within a population has been reported, but no clear mechanistic explanation for this pattern has emerged. Following a severe drought (summer 2012), we monitored over a 3-year period healthy (H) and declining (D) Pinus nigra trees co-occurring in a karstic woodland to highlight eventual individual-specific physiological differences underlying differential canopy dieback. We investigated differences in water and carbon metabolism, and xylem anatomy as a function of crown health status, as well as eventual genotypic basis of contrasting drought responses. H and D trees exploited the same water pools and relied on similar hydraulic strategies to cope with drought stress. Genetic analyses did not highlight differences between groups in terms of geographical provenance. Hydraulic and anatomical analyses showed conflicting results. The hydraulic tracheid diameter and theoretical hydraulic conductivity were similar, but D trees were characterized by lower water transport efficiency, greater vulnerability to xylem conduit implosion and reduced carbohydrate stores. Our results suggest that extreme drought events can have different impacts on conspecific individuals, with differential vulnerability to xylem embolism likely playing a major role in setting the fate of trees under climate change.

This work provides an overview of the ecology of all bipartite cyanolichens of Italy, exploring the relationships between ecological factors and species traits. A matrix of 205 species and several ecological descriptors was subjected to multivariate analyses (classification and ordination). Six groups of species with similar ecology were delimited, arranged along a gradient of decreasing aridity and light intensity, from extreme dry habitats on sunny calcareous rocks to very humid and shaded habitats on tree bark. The relationships between ecological species groups and traits were assessed by Principal Component Analysis, carried out on a matrix of ecological species groups and percent occurrences of 11 morpho-biological traits in each group. Along the gradient from arid to humid environments, and from more primeval substrata (rocks, mineral soils) to more recent ones (organic soils, tree bark), morphologically simpler, sexually reproducing cyanolichens are gradually replaced by more complex, often asexual species, which suggests that the current ecology of cyanolichens may retain a phylogenetic signal, indicative of the evolutionary footprint in species adaptation processes.

open 5 no An outline of the main distribution patterns of lichens in the ecoregions of Italy, accounting for their climatic, geographic, and environmental features, is still missing. On the basis of a GIS-based analysis, we summarized: (1) the main features (e.g., surface, climate, landscape, topographic heterogeneity, bedrock, eutrophication) of the 9 ecoregions adopted in ITALIC, the information system on Italian lichens, and (2) the patterns of richness, functional traits, and ecological requirements of lichens in the ecoregions. Our GIS-based analysis describes for the first time the main features of the 9 ecoregions adopted in ITALIC, highlighting differences which could explain the main lichen patterns. Overall, the exploration of the Italian lichen biota is still a work in progress, some regions being still underexplored, especially in the South, with new taxa being reported every year. Our research could provide a baseline for further advancements in the understanding of species richness and community composition of Italian lichens, at a regional scale. none Martellos S.; d'Agostino M.; Chiarucci A.; Nimis P.L.; Nascimbene J. Martellos S.; d'Agostino M.; Chiarucci A.; Nimis P.L.; Nascimbene J.

Recently, the Albanian Government started the process to join the European Union. This process also involves matching the EU parameters in protecting its biodiversity. In order to support the Albanian authorities, the Italian Ministry of Foreign Affairs, General Directorate for Development Cooperation (DGCS) and the International Union for Conservation of Nature (IUCN) joined efforts in the project “Institutional Support to the Albanian Ministry of Environment, Forest and Water Administration for Sustainable Biodiversity Conservation and Use in Protected Areas”. This project aims at identifying priority needs in safeguarding ecosystem services and biodiversity conservation. Another project funded by the EU – “Strengthening capacity in National Nature Protection – preparation for Natura 2000 network” – started in 2015 with the aim to raise awareness for assisting local and national Albanian institutions to better exploit the potential of protected areas. One of the main issues encountered during these projects was the need for a national biodiversity data repository. The Biodiversity National Network of Albania (BioNNA) has been created to aggregate occurrence records of plants and animals and aims at becoming the most relevant source of information for biodiversity data as far as Albania is concerned. In this paper, the authors detail structure and data of BioNNA, including the process of data gathering and aggregation, taxonomic coverage, software details and WebGIS development. BioNNA is a milestone on the path towards Albania’s inclusion in the EU and has also a relevant potential social relevance for improving people’s awareness on the importance of biodiversity in the country.

SUMMARYSpecies distribution data are critical information sources when it comes to implementing the multiple Aichi Targets set by the international Convention on Biological Diversity. Although there have been international-scale efforts to aggregate distribution data, the magnitudes and locations of the gaps in biodiversity knowledge remain unclear. In this study, we use a large database, including over 200 000 species occurrence records, to identify knowledge gaps in biodiversity inventories for nine animal taxa in a Mediterranean biodiversity hotspot. Spatial modelling methods were employed to relate the completeness of inventories to population, road and protected area density. The completeness of faunistic inventories was correlated with the amount of protected areas, roads and population density. Despite more than 200 years of faunistic sampling, knowledge of the distributions of most animal taxa is still limited, especially for invertebrates. As the window of opportunity for achieving Aichi Targets 11 and 19 begins to close, means of filling such knowledge gaps are required. We argue that a combination of quantitative tools and citizen science data collection programmes may help inform conservation decisions.

Ongoing variations in rainfall and temperature regimes affect the physiology and productivity of grapevines, calling for irrigation in drought-prone areas. During vintage 2015, we monitored plants water status and indirectly assessed rooting depth and exploited water sources (oxygen isotope analyses) in a mature Vitis vinifera cv. Malvasia Istriana vineyard on red soils ("terra rossa") developed on highly permeable carbonate rocks. We also investigated effects of topsoil irrigation or late summer rains on plant water status and yield. Under the harsh summer environmental conditions of 2015, the plant water status was overall favorable (moderate water deficit) and never reached critical levels, suggesting that irrigation was not mandatory. Leaf conductance to water vapor (g(L)) measured in July decreased by about 70% compared to spring, while minimum leaf water potential (Psi(min)) dropped by only 16%, suggesting an isohydric behavior of the cultivar (strict stomatal control of transpiration). Both Psi(min) and g(L) reached a minimum in July (peak of drought), and returned to pre-drought values in late summer. Rainfalls or supplemental irrigation (about 40 mm) promoted prompt recovery of plant water status. Irrigation treatments or occasional summer rainfalls can influence the water status of plants, although roots have access to deep water sources. In fact, the isotopic composition of xylem sap was similar to that of soil water sampled in a nearby deep cave, supporting the hypothesis that deep soil is the main water source for grapevines in karstic areas during summertime. Deficit irrigation, based on careful evaluation of physiological indicators of plant water status, might be an effective strategy for promoting sustainable viticulture, and a rationale use of water resources in karstic ecosystems.

This paper, based on data from the latest checklist of Italy, analyzes the distribution patterns of rare and common lichen species within biogeographically homogeneous versus heterogeneous areas of Italy, and the relationships with some main drivers of rarity and commonness. The following data were used: 1) commonness-rarity values of 2565 species in nine ecoregions; 2) frequency of 353 nationally rare and 387 nationally common species in 21 administrative regions. The following functional and ecological traits were considered: growth form, photobiont(s), type of reproduction, substrata, bioclimatic range, ecological indicator values for aridity and eutrophication, and poleophoby. Within each ecoregion, rare species by far outweigh common species but about one third of these are common in other ecoregions. At the level of regional floras, rarity is significantly associated with epiphytic substrata, non-trebouxioid photobionts and high air humidity, while commonness is associated with saxicolous substrata, trebouxioid photobionts and eutrophication. Rarity seems to mainly depend on two factors, bioclimate (many rare species are outside the limit of their bioclimatic optima) and reduced availability of suitable habitats (e.g. old-growth forests), while commonness is mainly related to disturbance (eutrophication, creation of drier habitats). Most of the nationally rare lichens belong to an oceanic-suboceanic element with tropical affinities or to a small set of continental species with their optima in the dry steppe biome, which suggests that many rare species can persist in microrefugia, that is sites with microclimates that support small populations of species beyond the boundaries of the climatic limits of their main distributions.

In this contribution, new data concerning bryophytes, fungi, and lichens of the Italian flora are presented. It includes new records and confirmations for the bryophyte genera Diplophyllum and Ptychostomum, the fungal genera Arrhenia, Gymnosporangium, and Sporidesmium and the lichen genera Arthonia, Coenogonium, Flavoplaca, Gyalolechia, Parmotrema, Peltigera, Pterygiopsis, Squamarina, Tornabea, and Waynea.

[ES]El proyecto Open Discovery Space (ODS) fue concebido para introducir prácticas innovadoras de enseñanza y aprendizaje basadas en recursos en escuelas europeas, para promover la creación de comunidades entre escuelas europeas y para impulsar la demanda por parte de los profesores de recursos educativos abiertos. Después de tres años aplicando el modelo de innovación ODS, más de 2.000 escuelas europeas han llevado a cabo diversas experiencias de innovación tecnológica para lograr los objetivos del proyecto. Este artículo describe las experiencias y resultados de ODS en siete países europeos, junto con las actividades internacionales que pretenden ampliar el alcance del proyecto más allá de los límites europeos.

T and B lymphocyte subsets have been not univocally associated to Graft-versus-host disease (GVHD) and relapse of hematological malignancies after stem cell transplantation (SCT). Their sequential assessment together with B and T cell neogenesis indexes has been not thoroughly analysed in relation to these changing and interrelated immunologic/clinic events yet. Lymphocyte subsets in peripheral blood (PB) and B and T cell neogenesis indexes were analysed together at different time points in a prospective study of 50 patients. Principal component analysis (PCA) was used as first step of multivariate analysis to address issues related to a high number of variables versus a relatively low number of patients. Multivariate analysis was completed by Fine-Gray proportional hazard regression model. PCA identified 3 clusters of variables (PC1-3), which correlated with acute GVHD: PC1 (pre-SCT: KRECs≥6608/ml, unswitched memory B 44%, CD8+TCM cells>4%; HR 1.9, p = 0.01), and PC3 (at aGVHD onset: CD4+TEMRA69%, switched memory CD19+ = 0 cells and KRECs

Easily measurable functional traits can be used as proxies in the selection of drought-tolerant saplings for reforestation in Mediterranean ecosystems. Heat and drought events—increasing both in frequency and severity—have led to forest decline, and are a serious threat for the Mediterranean biome. Whereas drought tolerance of adult trees of different Mediterranean species has been widely investigated, this is not the case for saplings and young trees. We analysed correlations and trade-offs among leaf (water potential at the turgor loss point, Ψ tlp, modulus of elasticity, e, osmotic potential at full turgor, π 0, leaf capacitance, C leaf_dw, leaf venation, VLA, leaf mass per area, LMA) and stem (wood capacitance and wood density, C wood and D wood, stem-specific conductivity and water potential inducing 50% loss of hydraulic conductance) functional traits of saplings for 14 woody species of the Mediterranean flora. The results support previously reported correlations among functional traits known to confer drought tolerance to plants. In particular, Ψ tlp was positively correlated to π 0, C leaf_dw and VLA, while negatively correlated to e and LMA. A highly significant correlation was highlighted between C wood and D wood. Overall, we observed surprisingly low symplastic and apoplastic resistance. We identify some easily measurable traits (π 0 and LMA), which evidence seedlings’ ability to cope with drought, and which therefore could be used as proxies in the selection of drought-tolerant saplings for reforestation in Mediterranean areas.

Nowadays, urban areas play a crucial role in biodiversity conservation and habitat protection despite the constant pressures on which these habitats are subjected. They may even host relatively new plant communities due to the peculiar ecosystem where they vegetate. The port of Trieste (NE Italy) is characterized by a mixed mosaic of intensely human impacted areas (where commercial activities are still ongoing) flanked by abandoned areas where vegetation persists or has spontaneously recovered. In this study, we sampled the whole port area through a stratified random sampling by placing multiscalar nested plots in four different habitats (strata) previously identified by photo-interpretation. Plant species richness and abundance were assessed in each plot. Each species was then classified as native or alien and patterns of species richness and complementarity were compared among habitats. Results show that there is a significant difference in species richness patterns among habitats, while observed patterns are likely to vary at different spatial scales. As expected, urban plots account for most of the alien species in the sampling, while wooded plots cope better with invasion, accounting for a lower alien/native ratio. These results highlight how habitat diversity enhances biodiversity in urban areas and how it could provide an effective filtering effect able to reduce the spread of alien species. In addition, we provide further evidence for the use of multi-scale approaches in order to study the complex relationships between spatial heterogeneity and plant species richness.