305,178 research outputs found
Moderni strumenti gestionali di dati floristici e vegetazionali: un esempio di geodatabase relazionale per la città di Trieste
No full textI recenti sviluppi nel campo dell’informatizzazione e conservazione della biodiversità stanno portando allo sviluppo
di nuovi sistemi informatici, che rendono possibile una efficiente raccolta, modifica, analisi e condivisione di dati e
metadati. In quest’ottica è stato sviluppato un geodatabase che organizza dati di flora e vegetazione dell’area di Trieste, provenienti
da diversi dataset e raccolti nell’ambito di vari progetti del Dipartimento di Scienze della Vita dell’Università di Trieste.
A questi sono stati aggiunti i dati sul verde pubblico e sulle specie arboree ottenuti dal Comune di Trieste. I dataset sono
stati standardizzati per sistema di riferimento e tassonomia, e successivamente integrati in un database PostgreSQL, abbinato
all’estensione spaziale PostGIS. Il geodatabase, interfacciato con un sistema GIS, è risultato un indispensabile strumento per
la visualizzazione dei dati e per la loro analisi spaziale testo
Metodi quantitativi per la redazione di flore (parte II): strategie di indagine floristica basate su approcci probabilistici
No full textLa redazione di una flora richiede enormi sforzi da parte del florista, spesso con risultati incompleti. Le flore sono generalmente redatte conducendo le attività di campo senza alcun protocollo quantitativo standardizzato, ma secondo criteri soggettivi, che scaturiscono da una combinazione di abilità, esperienza e intuito del florista (il cosìddetto “algoritmo del botanico” sensu Palmer et al. 2002). Se da un lato questo approccio aiuta a massimizzare il numero di taxa rilevati sul campo, dall’altro le flore così prodotte possono differire sensibilmente in quantità e qualità dei dati raccolti. Il passaggio verso un tipo di campionamento probabilistico – anziché opportunistico – è dunque auspicabile per poter (i) applicare analisi statistiche rigorose e comparabili, (ii) confrontare flore di regioni e periodi diversi (Chiarucci, Palmer 2006) e (iii) facilitare la riproducibilità e verificabilità di metodi e risultati. Lo scopo di questo lavoro è quindi quello di sperimentare l’introduzione di approcci probabilistici nella ricerca floristica e misurarne l’efficacia
Valutazione dei Servizi Ecosistemici in ambiente urbano come strumento per l’adattamento ai Cambiamenti Climatici
No full textSTUDIO CONOSCITIVO DEI CAMBIAMENTI CLIMATICI E DI ALCUNI LORO IMPATTI IN FRIULI VENEZIA GIULIA PRIMO REPORT – marzo 2018 Supporto alla predisposizione di una strategia regionale di adattamento ai cambiamenti climatici e per le azioni di mitigazion
Toc, Toc... C’è qualcuno in casa? Svelare la diversità degli animali che vivono nelle nostre abitazioni attraverso la citizen science: il progetto AIDA atre anni dalla sua creazione
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
More species, less effort: Designing and comparing sampling strategies to draft optimised floristic inventories
No full textFloristic inventories are an essential part of basic and applied research in botany. Despite their long history, floristic research is still carried out following non-objective (preferential) sampling approaches. Accordingly, final outputs (i) are extremely variable in the quality and quantity of collected data and hardly repeatable, (ii) rely on the researcher ability, and (iii) miss the basic assumptions to allow inferential statistical analyses. The aim of this work is to explore the drafting of a floristic inventory by means of geostatistical approaches to locate sampling units (plots) in the study area. We planned, carried out and then compared two different sampling strategies: (i) ‘basic strategy’, a stratified random sampling design based solely on a spatial optimization criterion (no prior information is available), and (ii) ‘advanced strategy’, a sampling design based on the maximisation of the spectral heterogeneity among sampling units, quantified in terms of Normalized Difference Vegetation Index values (NDVI). The strategy that maximises collected floristic information was assessed based on a combination of descriptive and quantitative statistics, such as (i) the completeness of the floristic inventory, (ii) the steepness of the rarefaction curves, (iii) the sampling time effort, and (iv) the plot contribution to the total β diversity. The 'advanced strategy' detects more species than the 'basic strategy' in all the sampling sites. The 'advanced strategy' accumulates species more quickly than the 'basic strategy'. The 'advanced strategy' selects sampling units more homogeneously contributing to total β diversity; in addition, they are better spatially arranged across the study area to capture environmental peculiarities of sampling sites. The 'advanced strategy' needs a little more effort in the design of the sampling strategy, but it is more effective than the 'basic strategy' in drafting a species inventory. We provide here the R routine to perform the 'advanced strategy', which can be profitably and freely used in any other geographic location and vegetation context
Determining plant diversity within interconnected natural habitat remnants (Ecological network) in an agricultural landscape: A matter of sampling design?
No full textIn intensively used and human-modified landscapes, biodiversity is often confined to remnants of natural habitats. Thus, identifying ecological networks (ENs) necessary to connect these patches and maintain high levels of biodiversity, not only for conservation but also for the effective management of the landscape, is required. However, ENs are often defined without a clear a-priori evaluation of their biodiversity and are seldom even monitored after their establishment. The objective of this study was to determine the adequate number of replicates to effectively characterize biodiversity content of natural habitats within the nodes of an EN in north-eastern Italy, based on vascular plant diversity. Plant communities within habitat types of the EN’s nodes were sampled through a hierarchical sampling design, evaluating both species richness and compositional dissimi-larity. We developed an integrated method, consisting of multivariate measures of precision (MultSE), rarefaction curves and diversity partitioning approaches, which was applied to estimate the minimum number of replicates needed to characterize plant communities within the EN, evaluating also how the proposed optimization in sampling size affected the estimations of the characteristics of habitat types and nodes of the EN. We observed that reducing the total sampled replicates by 85.5% resulted to sufficiently characterize plant diversity of the whole EN, and by 72.5% to exhaustively distinguish plant communities among habitat types. This integrated method helped to fill the gap regarding the data collection to monitor biodiversity content within existing ENs, considering temporal and economic resources. We therefore suggest the use of this quantitative approach, based on probabilistic sampling, to conduct pilot studies in the context of ENs design and monitoring, and in general for habitat monitoring
ITV-net: leveraging intraspecific trait variability to bridge vegetation science and trait-based research in Italy
No full textVegetation science is a branch of community ecology that relies on species identities and abundance to classify vegetation in coherent units and to explore species coexistence and turnover dynamics. The advent of trait-based ecology has expanded vegetation science, providing a framework that allows for a better understanding of plant strategies and the functional structure of communities. These complementary disciplines have remained largely independent among Italian plant ecologists. Therefore, in 2021, we launched the ITV-net initiative, a national collaborative effort for bringing together vegetation plots and field-measured plant trait data to develop a national platform that can serve both vegetation and trait-based ecologists. In the first data call, we were able to gather trait data on two key leaf traits (i.e., Leaf Area and Specific Leaf Area) for >700 species across 1,043 georeferenced vegetation plots, complemented with species relative abundances, across eight different EUNIS habitat types. Despite this remarkable first milestone, we aim to enlarge the scope of this initiative to include more vegetation plots and functional traits across more habitat types in Italy. Here, we provide an overview of the ITV-net initiative and its underlying methodological details as a ‘manifesto’ to spread the data call to other potential contributors in the Italian community of plant ecologists. Our ultimate objective is to bridge the vegetation science and trait-based ecological research in Italy towards developing a national database of vegetation plots and plant functional traits. We believe this effort will contribute to building a solid network among Italian plant ecologists to cross the artificial boundaries of different, yet complementary, disciplines
Cambiamenti climatici e specie aliene invasive
No full textSTUDIO CONOSCITIVO DEI CAMBIAMENTI CLIMATICI E DI ALCUNI LORO IMPATTI IN FRIULI VENEZIA GIULIA PRIMO REPORT – marzo 2018 Supporto alla predisposizione di una strategia regionale di adattamento ai cambiamenti climatici e per le azioni di mitigazion
I Servizi Ecosistemici e la loro valutazione economica
No full textSTUDIO CONOSCITIVO DEI CAMBIAMENTI CLIMATICI E DI ALCUNI LORO IMPATTI IN FRIULI VENEZIA GIULIA PRIMO REPORT – marzo 2018 Supporto alla predisposizione di una strategia regionale di adattamento ai cambiamenti climatici e per le azioni di mitigazion
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