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Drought-induced tree mortality frequently occurs in patches with different spatial and temporal distributions, which is only partly explained by inter- and intraspecific variation in drought tolerance. We investigated whether bedrock properties, with special reference to rock water storage capacity, affects tree water status and drought response in a rock-dominated landscape. We measured primary porosity and available water content of breccia (B) and dolostone (D) rocks. Saplings of Fraxinus ornus were grown in pots filled with soil or soil mixed with B and D rocks, and subjected to an experimental drought. Finally, we measured seasonal changes in water status of trees in field sites overlying B or D bedrock. B rocks were more porous and stored more available water than D rocks. Potted saplings grown with D rocks had less biomass and suffered more severe water stress than those with B rocks. Trees in sites with B bedrock had more favourable water status than those on D bedrock which also suffered drought-induced canopy dieback. Bedrock represents an important water source for plants under drought. Different bedrock features translate into contrasting below-ground water availability, leading to landscape-level heterogeneity of the impact of drought on tree water status and dieback.

On the 29th of October 2018, a storm named “Vaia” hit North-Eastern Italy, causing the loss of 8 million m3 of standing trees and creating serious damage to the forested areas, with many economic and ecological implications. This event brought up the necessity of a standard procedure for windthrow detection and monitoring based on satellite data as an alternative to foresters’ fieldwork. The proposed methodology was applied in Carnic Alps (Friuli Venezia Giulia, NE Italy) in natural stands dominated by Picea abies and Abies alba. We used images from the Sentinel-2 mission: 1) to test vegetation indices performance in monitoring the vegetation dynamics in the short period after the storm, and 2) to create a windthrow map for the whole Friuli Venezia Giulia region. Results showed that windthrows in forests have a significant influence on visible and short-wave infrared (SWIR) spectral bands of Sentinel-2, both in the short and the long-term timeframes. NDWI8A and NDWI were the best indices for windthrow detection (R2 = 0.80 and 0.77, respectively) and NDVI, PSRI, SAVI and GNDVI had an overall good performance in spotting wind-damaged areas (R2 = 0.60–0.76). Moreover, these indices allowed to monitor post-Vaia forest die-off and showed a dynamic recovery process in cleaned sites. The NDWI8A index, employed in the vegetation index differencing (VID) change detection technique, delimited damaged areas comparable to the estimations provided by Regional Forest System (2545 ha and 3183 ha, respectively). Damaged forests detected by NDWI8A VID ranged from 500 m to 1500 m a.s.l., mainly covering steep slopes in the south and east aspects (42% and 25%, respectively). Our results suggested that the NDWI8A VID method may be a cost-effective and accurate way to produce windthrow maps, which could limit the risks associated with fieldwork and may provide a valuable tool to plan tree removal interventions in a more efficient way.

Lake Doberdò (Classical Karst) is a well-known example of karst lakes, temporary lakes that seasonally fill and empty through springs and swallow holes connected to the underground waters. It is an area of exceptional interest for geological-geomorphological and biodiversity conservation, and is part of the Natura 2000 network. Its peculiar hydro-ecological nature allows an impressive variety of species and habitats. A phytosociological survey was carried out to provide a comprehensive analysis of the vegetation. On the basis of 177 phytosociological relevés and multivariate analysis 43 communities were found, belonging to Platyhypnidio-Fontinalietea antipyreticae, Lemnetea minoris, Potametea pectinati, Bidentetea tripartitae, Isoëto-Nanojuncetea, Phragmito-Magnocaricetea, Agrostietea stoloniferae, Molinio-Arrhenatheretea, Filipendulo ulmariae-Convolvuletea sepium, Alnetea glutinosae, Rhamno catharticae-Prunetea spinosae, Alno glutinosae-Populetea albae. The Leucojo aestivi-Poetum pratensis association including waterside periodically flooded meadows is validated. Compared to the past, various communities show a change in their distribution while some valuable coenoses were not found. 21 communities are attributed to 8 Annex I Habitats of the 92/43/EEC Directive. The study confirms the high value of Lake Doberdò for biodiversity conservation but highlights an ongoing process of environmental change due to both natural and human-related causes including modifications of the hydrological regime and abandonment of traditional agricultural practices. An overview of the features of Lake Doberdò is provided to compare this disappearing lake with the karst groundwater-dependent wetlands found in Ireland called “turloughs”, corresponding to Annex I Habitat 3180*. Also on the basis of the current interpretation and distribution of this habitat type at the EU level, a proposal is presented to recognize and protect this outstanding area of the Natura 2000 network in Italy as the habitat 3180*, modelled on Irish turloughs.

Biological invasions are deemed to be the second most important global driver of biodiversity loss, right behind habitat destruction and fragmentation. In this study, we aimed at testing if community invasibility, defined as the vulnerability to invasion of a community, could be associated with the characteristics of a given habitat, as described by the composition and structure of its native species. Based on a probabilistic sampling of the alien flora occurring in the temperate wetland Lake Doberd&ograve, (Friuli Venezia Giulia region, NE Italy) and using a null-model-based approach, the observed occurrence of Invasive Alien Species (IAS) within sampling units was randomized within habitats. While testing the degree of invasibility for each habitat within the wetland, our null hypothesis postulated that habitats are equally invaded by IAS, as IAS can spread homogeneously in the environment thanks to their plasticity in functional traits that makes them able to cope with different ecological conditions. The obtained results comparing observed IAS frequencies, abundance and richness to those obtained by the null model randomizations show that, for all habitats, invasion was selective. Specifically, a marked preference for habitats with an intermediate disturbance level, a high nutrients level and a medium-high light availability was observed, while an avoidance was detected for habitats characterized by lower levels of nutrients and light availability or extreme conditions caused by prolonged submersion. This method allows us to provide useful information using a simple-to-run simulation for the management of the IAS threat within protected areas. Moreover, the method allows us to infer important ecological characteristics leading to habitat invasion without sampling the environmental characteristic of the habitats, which is an expensive operation in terms of time and money.

Increased frequency of tree mortality and forest decline due to anomalous drought events calls for the adoption of effective monitoring of tree water status over large spatial and temporal scales. We correlated field-measured and remotely sensed plant water status parameters, to test the possibility of monitoring the risk of drought-induced dehydration and hydraulic failure using satellite images calibrated on reliable physiological indicators of tree hydraulics. The study was conducted during summer 2019 in the Karst plateau (NE Italy) in a woodland dominated by Fraxinus ornus L., Sentinel-2 images were acquired on a seasonal scale on the same dates when absolute water content (AbWC), relative water content (RWC), and minimum water potential (&Psi, min) were measured in the field. Plant water status parameters were correlated with normalized difference vegetation index (NDVI and NDVI 8A), normalized difference water index (NDWI), and soil-adjusted vegetation index (SAVI). Significant Pearson and Spearman linear correlations (&alpha, &lt, 0.05) emerged between all tree-level measured variables and NDWI, while for NDVI, NDVI 8A, and SAVI no correlation was found. Our results suggest the possibility of using the NDWI as a proxy of tree water content and water potential.

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 paper we propose a method to produce maps of fire danger index (FDI). The index includes in the formula a vegetation pyrogenic potential index (VPPI) based on floristic phytosociological data. The map of FDI is produced by integrating available phytosociological maps of vegetation, geomorphology and climate, using the Geographic Information System technology. The method is applied to an area of the coastal Classical Karst (NE-Italy). While fire risk maps based on the incidence of previous fires are useful for facilitating emergency operations, e.g. the allocation of fire fighting resources, we conclude that the proposed index offers an effective tool to plan actions for fire prevention.

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.

Recently, methods for constructing Spatially Explicit Rarefaction (SER) curves have been introduced in the scientific literature to describe the relation between the recorded species richness and sampling effort and taking into account for the spatial autocorrelation in the data. Despite these methodological advances, the use of SERs has not become routine and ecologists continue to use rarefaction methods that are not spatially explicit. Using two study cases from Italian vegetation surveys, we demonstrate that classic rarefaction methods that do not account for spatial structure can produce inaccurate results. Furthermore, our goal in this paper is to demonstrate how SERs can overcome the problem of spatial autocorrelation in the analysis of plant or animal communities. Our analyses demonstrate that using a spatially-explicit method for constructing rarefaction curves can substantially alter estimates of relative species richness. For both analyzed data sets, we found that the rank ordering of standardized species richness estimates was reversed between the two methods. We strongly advise the use of spatially-explicit rarefaction methods when analyzing biodiversity: the inclusion of spatial autocorrelation into rarefaction analyses can substantially alter conclusions and change the way we might prioritize or manage nature reserves.

This study was carried out using Ixodes ricinus ticks collected during 2005 and 2006 from the Friuli Venezia Giulia (FVG) region in the northeastern part of Italy and an area along the Slovenian side of the western border of Italy. The results indicate that Rickettsia spp. is widely distributed throughout these areas, with the greatest prevalence in the central part of the FVG region. The prevalence of Rickettsia spp. was 4.5% during 2005 and 6.1% during 2006. By sequencing the 16S rRNA gene, we show for the first time the presence of Rickettsia helvetica in I. ricinus ticks in the FVG region and the presence of R. monacensis in ticks in both areas. Furthermore, we detected a sequence with a high homology with that of R. limoniae in a tick obtained from the alpine zone.

The identification of shape and size of sampling units maximising species richness has major implications in conservation planning and monitoring actions. In this study we tested the effect of three sampling unit shapes (rectangles, squared, and randomly shaped sampling units) on the number of recorded plant species. We used a large dataset gathered in the network of protected areas of the Siena Province, Italy, as part of a joint project with the Italian National Forest Inventory. This dataset is composed of plant species occurrence data recorded from 604 plots (10m x10m), each divided in a grid of 16 contiguous subplot units (2.5 m x 2.5 m). Furthermore, we evaluated the effect of plot orientation along the main environmental gradient, related to slope, to understand how the selection of plot orientation (when elongated plots are used) influences the number of species collected. In total, 1041 plant species were recorded from the study plots. Species richness was significantly higher using randomly shaped sampling units compared to rectangular and squared units. Although rectangular units captured a significantly larger number of species than squared ones, plot orientation along the main environmental gradient (terrain slope) did not show a systematic effect on the number of recorded species. The decision of whether or not using rectangular versus squared plots should therefore depend upon the objectives of the survey and the characteristics of the area to be surveyed, with squared plots being more suitable for assessing species composition of more homogeneous vegetation units while rectangular plots being more suited for recording more species in the pooled sample of a large area. If the aim of a survey is to evaluate the biodiversity and conservation value of a ecosystem/community, sampling protocols that maximise the number of recorded species given the same sampling effort should be used. Furthermore, considerations on the orientation of rectangular plots should be carefully made to enhance reproducibility of collected data and correctly interpret the results of a survey. This information is crucial to develop cost-effective surveys and monitoring programs aimed at maximising the number of collected species.

The identification of shape and size of sampling units that maximises the number of plant species recorded in multiscale sampling designs has major implications in conservation planning and monitoring actions. In this paper we tested the effect of three sampling shapes (rectangles, squared, and randomly shaped sampling units) on the number of recorded species. We used a large dataset derived from the network of protected areas in the Siena Province, Italy. This dataset is composed of plant species occurrence data recorded from 604 plots (10 m × 10 m), each divided in a grid of 16 contiguous subplot units (2.5 m × 2.5 m). Moreover, we evaluated the effect of plot orientation along the main environmental gradient, to examine how the selection of plot orientation (when elongated plots are used) influences the number of species collected. In total, 1041 plant species were recorded from the study plots. A significantly higher species richness was recorded by the random arrangement of 4 subplots within each plot in comparison to the ‘rectangle’ and ‘square’ shapes. Although the rectangular shape captured a significant larger number of species than squared ones, plot orientation along the main environmental gradient did not show a systematic effect on the number of recorded species. We concluded that the choice of whether or not using elongated (rectangular) versus squared plots should dependent upon the objectives of the specific survey with squared plots being more suitable for assessing species composition of more homogeneous vegetation units and rectangular plots being more suited for recording more species in the pooled sample of a large area.

Invasion by alien plant species may be rapid and aggressive, causing erosion of local biodiversity. This is particularly true for islands, where natural and anthropogenic corridors promote the rapid spread of invasive plants. Although evidence shows that corridors may facilitate plant invasions, the question of how their importance in the spread of alien species varies along environmental gradients deserves more attention. Here, we addressed this issue by examining diversity patterns (species richness of endemic, native and alien species) along and across roads, along an elevation gradient from sea-level up to 2050 m a.s.l. in Tenerife (Canary Islands, Spain), at multiple spatial scales. Species richness was assessed using a multi-scale sampling design consisting of 59 T-transects of 150 m × 2 m, along three major roads each placed over the whole elevation gradient. Each transect was composed of three sections of five plots each: Section 1 was located on the road edges, Section 2 at intermediate distance, and Section 3 far from the road edge, the latter representing the “native community” less affected by road-specific disturbance. The effect of elevation and distance from roadsides was evaluated for the three groups of species (endemic, native and alien species), using parametric and non-parametric regression analyses as well as additive diversity partitioning. Differences among roads explained the majority of the variation in alien species richness and composition. Patterns in alien species richness were also affected by elevation, with a decline in richness with increasing elevation and no alien species recorded at high elevations. Elevation was the most important factor determining patterns in endemic and native species. These findings confirm that climate filtering reflected in varying patterns along elevational gradients is an important determinant of the richness of alien species (which are not adapted to high elevations), while anthropogenic pressures may explain the richness of alien species at low elevation.

We propose a method that has general relevance to the digital representation of spatial variation of multivariate landscape data. It is based on the average similarity that operational geographic units (OGU) have with the adjacent ones according to characters relevant understanding landscape patterns and dynamics. The method is flexible and easily executable within the technological framework of geographic information systems (GIS) that today is available even free of charge or at very low cost. An example shows how the method, applied to spatial data of a floristic project for the urban area of Trieste (NE-Italy), can identify floristically homogeneous patches and can quantify the heterogeneity of the transition zones between such patches.

The role of vegetation analysis by remote sensing (RS) and Geographical Information System (GIS) technology to support plans for sustainable development is discussed through a proposal of an index of ecosystem “integrity” or of regeneration capacity. The index is based on the vegetation “mass” of a given land cover type and the capacity that such mass has to contrast soil erosion. The index is therefore taking into account the effects of human activities and not merely the state of ecosystems in terms of their components. It would be very difficult, if not impossible, to calculate the proposed index without RS and GIS techniques. These allow, respectively, to collect and to analyze the spatial data at relative low cost and in relatively short times. Time and money are the limiting factors for all the management plans. As an example of application, we have calculated the index for the Santos estuary drainage basin (Brazil) selected as a case study within the ECOMANAGE project funded by European Commission. The area was chosen because of its great economic importance and for relevant environmental problems (industrial pollution and urbanization pressure) that could limit the development. For estimating the relative vegetation mass, we have used the Leaf Area Index, while for the soil erosion, we have used the revised universal soil loss equation model. The maps of ecosystem integrity produced by the application of the index may be very useful to guide the planners in the development of the urbanization process that is threatening the “Mata Atlantica” and the mangrove forests.

The aim of this study is to determine the correlation between nesting bird species richness in different natural habitats of the Triestine Carso and the corresponding floristic and vegetational types.

Socotra Island (Yemen), a global biodiversity hotspot, is characterized by high geo- morphological and biological diversity. In this study, we present a high-resolution vegetation map of the island based on combining vegetation analysis and classification with remote sensing. Two different image classification approaches were tested to assess the most accurate one in mapping the vegetation mosaic of Socotra. Spectral signatures of the vegetation classes were obtained through a Gaussian mixture distribution model, and a sequential maximum a posteriori (SMAP) classification was applied to account for the heterogeneity and the complex spatial pattern of the arid vegetation. This approach was compared to the traditional maximum like- lihood (ML) classification. Satellite data were represented by a RapidEye image with 5 m pixel resolution and five spectral bands. Classified vegetation releves were used to obtain the training and evaluation sets for the main plant communities. Postclassification sorting was performed to adjust the classification through various rule-based operations. Twenty- eight classes were mapped, and SMAP, with an accuracy of 87%, proved to be more effective than ML (accuracy: 66%). The resulting map will represent an important instrument for the elaboration of conservation strategies and the sustainable use of natural resources in the island. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original pub- lication, including its DOI. (DOI: 10.1117/1.JRS.7.073527)

The purpose of this paper is to assess the influence of several biotic and abiotic factors on the abundance of waterbirds in the Grado-Marano Lagoon. The Grado-Marano Lagoon is situated in the Northeast of the Adriatic Sea with an extension of approximately 160 km 2 . ASTER satellite images were utilized to classify different types of morphologies and habitat, including sea grass meadows. Four abiotic factors (total nitrogen, total phosphorous, alkalinity and sediment texture) and three biotic factors (benthic community, sea grass meadows and waterbird guild abundance) were integrated into a GIS. A regular UTM grid of square cells (Operational Geographic Units, OGUs), 1km x 1km, was superimposed on the entire lagoon. Using the Hierarchical Cluster Analysis (HCA) technique it was possible to delineate ecological units (clusters of OGUs) and Principal Component Analysis (PCA) was used to reduce the dimensionality of the factors considered. Subsequently, Correspondence Analysis (CA) was used to examine the relationship between waterbird guild abundance and ecological units.

The Friuli Venezia Giulia region (FVG) and the transborder territory Italy/Slovenia are endemic for Lyme borreliosis and, more recently, also for Anaplasma phagocytophilum infections. In the present study, we determined the density of questing Ixodes ricinus ticks and their infection rates with Borrelia burgdorferi and A. phagocytophilum in the four main biogeographical regions present in the study area. Within these regions, stations for collecting ticks were selected. The pathogens were detected by PCR methods specific for the two infectious agents. The prevalences of infection varied among different landscapes. The local potential risk of human infection through tick bite was drawn from tick abundance and prevalence of infection in ticks: The level of risk for B. burgdorferi infection was found to be highest in the transborder Karst territory. In that environment up to 45.5% of the ticks were infected. The prevalence dropped approaching the alpine environment (13.2%). Conversely, the potential risk to be bitten by ticks infected with Anaplasma was quite low: The annual average infection prevalence in ticks was 1.6%.

The present monitoring project aimed at detecting the prevalence of Borrelia burgdorferi in ticks in the Friuli Venezia Giulia (FVG) Region (north-eastern Italy) and along the western border of Slovenia and to determine the Borrelia circulating genospecies. Since Anaplasma phagocytophilum had been found in the study area, we also evaluated the co-infection of the two pathogens in tick (Ixodes ricinus) populations. The ticks collected during 2005 in 15 sites located in the study area were analyzed to detect the presence of B. burgdorferi by amplifying the intergenic spacer 5S–23S. Genotyping was performed using a new nested-PCR–RFLP method, targeting the ospA gene. A. phagocytophilum was searched for by amplifying the epank1 gene. The average infection rate of ticks with B. burgdorferi varied from 11.8% to 45.5% in the different study sites. A. phagocytophilum was present in the 1.6% of the investigated ticks and apparently homogeneously distributed. The percentage of co-infection with B. burgdorferi sensu lato was 3.4%. At least four different Borrelia species were found: B. afzelii (54.9%), B. garinii (31.7%), B. burgdorferi sensu stricto (6.1%), and 4.9% of a species unidentified whose phylogenetic analysis showed no similarity with any of the known Borrelia genospecies.

The risk exposure to Lyme borreliosis in the Friuli Venezia Giulia region, in north-eastern Italy, was investigated on the basis of the abundance of infected ticks. A total of 2620 questing Ixodes ricinus ticks were collected at 25 sampling sites during spring 2005 and 2006, and nymphs and adult females were examined for Borrelia burgdorferi. The distribution of infected ticks was analysed in relation to a set of environmental parameters obtained from satellite, climatic, topographic, and biotic data. A multiple linear regression model was developed to predict the abundance of infected ticks and using GIS facilities, it was possible to elaborate an infected tick distribution map.

We report, for the first time, the presence of tick-borne encephalitis (TBE) virus in the tick Ixodes ricinus collected in the Friuli Venezia Giulia region of north-eastern Italy. Using molecular methods, we demonstrate that the TBE virus carried by ticks from FVG is a western European strain. Sequence analysis of the 5' NCR showed 98.4% identity to the Neudoerfl strain.