Geometric shortest path containers [online]

In this paper, we consider Dijkstra\u27s algorithm for the single source single target shortest path problem in large sparse graphs. The goal is to reduce the response time for on-line queries by using precomputed information. Due to the size of the graph, preprocessing space requirements can be only linear in the number of nodes. We assume that a layout of the graph is given. In the preprocessing, we determine from this layout a geometric object for each edge containing all nodes that can be reached by a shortest path starting with that edge. Based on these geometric objects, the search space for on-line computation can be reduced significantly. Shortest path queries can then be answered by Dijkstra\u27s algorithm restricted to edges where the corresponding geometric object contains the target. We present an extensive experimental study comparing the impact of different types of objects. The test data we use are real-world traffic networks, the typical field of application for this scenario. Furthermore, we present new algorithms as well as an empirical study for the dynamic case of this problem, where edge weights are subject to change and the geometric containers have to be updated. We evaluate the quality and the time for different update strategies that guarantee correct shortest paths. Finally, we present a software framework in C++ to realize the implementations of all of our variants of Dijkstra\u27s algorithm. A basic implementation of the algorithm is refined for each modification and - even more importantly - these modifications can be combined in any possible way without loss of efficiency

Red Listing plants under full national responsibility: Extinction risk and threats in the vascular flora endemic to Italy

Taxa endemic to a country are key elements for setting national conservation priorities and for driving conservation strategies, since their persistence is entirely dependent on national policy. We applied the IUCN Red List categories to all Italian endemic vascular plants (1340 taxa) to assess their current risk of extinction and to highlight their major threats. Our results revealed that six taxa are already extinct and that 22.4% (300 taxa) are threatened with extinction, while 18.4% (247; especially belonging to apomictic groups) have been categorized as Data Deficient. Italian endemic vascular plants are primarily threatened by natural habitat modification due to agriculture, residential and tourism development. Taxa occurring in coastal areas and lowlands, where anthropogenic impacts and habitat destruction are concentrated, display the greatest population decline and extinction. The national network of protected areas could be considered effective in protecting endemic-rich areas (ERAs) and endemic taxa, but ineffective in protecting narrow endemic-rich areas (NERAs), accordingly changes to the existing network may increase the effectiveness of protection. For the first time in the Mediterranean Basin biodiversity hotspot, we present a comprehensive extinction assessment for endemic plants under the full responsibility of a single country. This would provide an important step towards the prioritization and conservation of threatened endemic flora at Italian, European, and Mediterranean level. A successful conservation strategy of the Italian endemic vascular flora should implement the protected area system, solve some taxonomical criticism in poorly known genera, and should rely on monitoring threatened species, and on developing species-specific action plans

Traditionelle Heilpflanzen als kulturelle Schlüsselarten für Naturschutz und Ökosystemrenaturierung - Ergebnisse einer Studie in den Südtiroler Alpen

Despite the manifold environmental legislation, initiatives, agreements, and conventions at the national and international level, loss of biodiversity at the global level has not yet been significantly halted. Thus, new strategies are needed, especially with regard to the restoration of ecosystems and land-use systems that have high biodiversity and pro-vide diverse ecosystem services. In order to involve local communities more in conservation and restoration efforts, the concept of Cultural Keystone Species could be applied. Focusing on traditional medicinal plants in the Autonomous Province of Bozen-South Tyrol in the Alps (northern Italy), we identified 10 such Cultural Keystone Species with high importance (e.g., multiple benefits, medicinal uses) for the local population. The occurrence of these species in open land and forests and their use as wild plants or cultivation in gardens can promote the acceptance of the protection and active restoration of corresponding habitatsTrotz der vielfältigen Umweltgesetzgebungen, Initiativen, Vereinbarungen und Konventionen auf nationaler und internationaler Ebene ist der Verlust der biologischen Vielfalt auf globaler Ebene bisher nicht signifikant aufgehalten worden. Es bedarf also neuer Strategien, insbesondere was die Renaturierung von Öko- beziehungsweise Landnutzungssystemen angeht, die eine hohe Biodiversität und vielfältige Ökosystemleistungen aufweisen. Um die lokale Bevölkerung stärker in Naturschutz- und Renaturierungsbestrebungen miteinzubeziehen, bietet sich das Konzept der kulturellen Schlüsselarten an. Wir identifizierten mit Blick auf traditionelle Heilpflanzen in der Provinz Bozen-Südtirol in den Alpen (Norditalien) zehn solcher kulturellen Schlüsselarten mit einer hohen Bedeutung (etwa Mehrfachnutzen, medizinische Anwendungen) für die Bevölkerung. Das Vorkommen dieser Arten in Offenland und Wäldern und ihre Nutzung als Wildpflanze oder kultiviert in Gärten kann die Akzeptanz für den Schutz und die aktive Wiederherstellung entsprechender Lebensräume fördern

Microclimate predicts frost hardiness of alpine 'Arabidopsis thaliana' populations better than elevation

In mountain regions, topological differences on the microscale can strongly affect microclimate and may counteract the average effects of elevation, such as decreasing temperatures. While these interactions are well understood, their effect on plant adaptation is understudied. We investigated winter frost hardiness of 'Arabidopsis thaliana' accessions originating from 13 sites along altitudinal gradients in the Southern Alps during three winters on an experimental field station on the Swabian Jura and compared levels of frost damage with the observed number of frost days and the lowest temperature in eight collection sites. We found that frost hardiness increased with elevation in a log-linear fashion. This is consistent with adaptation to a higher frequency of frost conditions, but also indicates a decreasing rate of change in frost hardiness with increasing elevation. Moreover, the number of frost days measured with temperature loggers at the collection sites correlated much better with frost hardiness than the elevation of collection sites, suggesting that populations were adapted to their local microclimate. Notably, the variance in frost days across sites increased exponentially with elevation. Together, our results suggest that strong microclimate heterogeneity of high alpine environments can preserve functional genetic diversity among small populations. Synthesis: Here, we tested how plant populations differed in their adaptation to frost exposure along an elevation gradient and whether microsite temperatures improve the prediction of frost hardiness. We found that local temperatures, particularly the number of frost days, are a better predictor of the frost hardiness of plants than elevation. This reflects a substantial variance in frost frequency between sites at similar high elevations. We conclude that high mountain regions harbor microsites that differ in their local microclimate and thereby can preserve a high functional genetic diversity among them. Therefore, high mountain regions have the potential to function as a refugium in times of global change

Pesticide contamination and associated risk factors at public playgrounds near intensively managed apple and wine orchards

BACKGROUND: Pesticide levels are generally monitored within agricultural areas, but are commonly not assessed at public places. To assess possible contamination of non-target areas, 71 public playgrounds located next to intensively managed apple and wine orchards were selected in four valleys of South Tyrol (northern Italy). Further, the impact of environmental site characteristics on the number and concentration of pesticides was assessed. Grass samples from the selected playgrounds were collected and screened for 315 pesticide residues using standard gas chromatography and mass spectrometry. RESULTS: Nearly half of the playgrounds (45%) were contaminated by at least one pesticide and a quarter (24%) by more than one. Eleven of the 12 different detected pesticides are classified as endocrine-active substances including the insecticide phosmet and the fungicide fluazinam showing the highest concentrations (0.069 and 0.26 mg kg−1, respectively). Additionally, one disinfectant and one preservation agent was found. Playgrounds in Venosta valley were most often contaminated (76% of all investigated playgrounds), highest concentrations were found in the Low Adige (2.02 mg kg−1). Pesticide concentrations were positively associated with areal proportion of apple orchards in the surroundings, the amount of rainfall and wind speed. In contrast, increasing global irradiance, opposite wind direction, increasing distance to agricultural sites and high wind speeds when pesticide application was not allowed were associated with decreasing pesticide contamination. CONCLUSION: This study is among the first investigating pesticide contamination of public playgrounds together with environmental factors in areas with pesticide-intensive agriculture at the beginning of the growing season. It is likely that playgrounds will be affected by more pesticides and higher concentrations over the course of the crop season. The result, that the majority of the detected pesticides are classified as endocrine active is worrisome as children are especially vulnerable. Hence, we recommend that pesticide risk assessments should better include protection measures for non-target areas

Notulae to the Italian native vascular flora: 17

In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, confirmations, and exclusions to the Italian administrative regions for taxa in the genera Anacyclus, Anthyllis, Bolboschoenus, Catapodium, Festuca, Hordeum, Lavandula, Ophrys, Pseudopodospermum, Rosa, Sorbus and Spergula. Nomenclatural and distribution updates, published elsewhere, and corrigenda are provided as Suppl. material 1

New Red List of the Italian vascular flora: nearing the end.

In 2011, MATTM and SBI started a collaboration for the New Red List of Italian Vascular Flora, according to the IUCN Categories and Criteria. IUCN Red Lists represent the most widely applied protocol for evaluating species extinction risk, because they facilitate objective and replicable assessments. National assessments provide a basis for conservation planning, representing an important starting points for further conservation actions. Data on species distribution gathered, from recent field surveys, herbarium specimens, published and unpublished data, were assembled with the collaboration of a large number of SBI members. All georeferenced records were validated by a selected group of botanists and organized in a 2 7 2 km cells grid in GIS environment. A database including distribution data, population trends and the main threats affecting taxa was developed. All the assessments were validated during several collective workshops. During 2016, the New Red List of the Italian Vascular Flora will be completed with the evaluation of more than 2000 taxa including Italian Policy species (152 taxa, listed in the annexes of Directive 92/43/CEE \u201cHabitat\u201d and Bern Convention), all Italian endemics (more than 1200 taxa, most part of taxonomically critical genera as Alchemilla, Hieracium, Pilosella, Ranunculus, Rubus and Taraxacum excluded) and all those species of potential conservation interest listed in 2012 for MATTM (more than 1500 taxa, some endemics included). Here, we present the updated status, in view of the ultimate goal that will be reached by the end of 2016. The publication of a book that will summarize all the work done is foreseen for 2017

Inventory of the non-native flora of Italy

In this paper we present a comprehensive inventory of the non-native vascular flora of Italy, which was produced within the project “A survey of the Italian non-native flora”, funded by the Italian Ministry for the Environment. Previously published floristic accounts were the main source of information. Historical records were critically revised and integrated with recent literature, data from herbaria and some unpublished information, so as to obtain a complete, up-to-date catalogue of the non-native vascular plant species that occur spontaneously in Italy. The inventory lists 1023 non-native species and subspecies, which account for 13.4% of all the Italian flora. The Italian non-native flora was divided, according to its residence time, into 103 archaeophytes and 920 neophytes. According to its current invasion status, it was classified into 437 casual (42.7% of all non-native) and 524 established taxa, the latter being divided into 361 naturalized non-invasive (35.3%) and 163 invasive taxa (15.9%). The inventory includes a group of 62 species (6.1%) that lack recent records (i.e. since 1950). By combining local expertise into a unified, nationwide scheme using a standardized method and terminology, the inventory provides the essential scientific basis for the development of plant invasion research and management in the country

The Red List of Italian endemic vascular plants

The Italian vascular flora is one of the richest in the European Union and the Italian peninsula is located at the centre of the Mediterranean Basin, one of the 25 world biodiversity hotspots with an exceptional loss of habitats and species (1). Preliminary to any conservation initiative concerning plant diversity, a prioritization of the most endangered species is needed. IUCN Red List protocol is widely recognized and used to evaluate the conservation status of a species, according to its estimated extinction risk (2). Assessing the conservation status of plants endemic to an entire nation is a key challenge, because of the huge amount of data, knowledge and information required. Such a result can be achieved only through the collaboration of many specialists and an adequate financial base. \u201cThe Red List of the Italian Flora\u201d project, promoted by the Ministry for Environment and Protection of Land and Sea General, Directorate for Protection of Nature and Sea, in collaboration with the Italian Botanical Society, started in 2013 with the aim to update the conservation status of Italian plants. In 2016 the assessment of all the vascular plants strictly endemics to Italy was completed. Considering all the Italian endemics, with the exclusion of taxonomically critical genera (i.e. Alchemilla, Hieracium, Ophrys, Pilosella, Ranunculus, Rubus and Taraxacum), a total of 1088 taxa was assessed. Three taxa are considered extinct (EX), one extinct in the wild (EW) and six are possibly extinct (CR[PE]). Around 27% of the Italian endemics are included in one of the major threat categories (CR, EN and VU), while c. 20% may become threatened with extinction in the near future (NT). Around half of the Italian endemic taxa (506) are widespread and abundant taxa (LC). Finally, 80 species (7%) were categorized as Data Deficient since the available data did not allow a robust assessment, indicating that further taxonomic and field studies should be undertaken in the next future