319 research outputs found
Patterns of co-occurrence of rare and threatened species in winter arable plant communities of Italy
Detecting patterns of species co-occurrence is among the main tasks of plant community ecology. Arable plant communities are important elements of agroecosystems, because they support plant and animal biodiversity and provide ecosystem services. These plant communities are shaped by both agricultural and environmental drivers. The pressure of intensive agriculture worldwide has caused the decline of many characteristic arable species and communities. Italy is the European country where arable plant biodiversity is the best preserved. In this study, we assessed the patterns of co-occurrence of rare and threatened arable plants in 106 plots of winter arable vegetation located from Piedmont to Calabria, in the mainland part of the country. For this purpose, we based our
investigation on the analysis of a recently acquired dataset and on the European list of rare and threatened arable plants. We highlight how dierent species of conservation interest tend to occur in the same community. On the other hand, generalist and more competitive taxa show similar patterns of co-occurrence. We suggest that single species of conservation value could be suitable indicators of
a well-preserved community. On the other hand, to be eective, conservation strategies should target the whole community, rather than single species
La campagna romana
Viene descritto il paesaggio vegetale della Campagna Romana (Lazio) ed illustrato il patrimonio floristico delle diverse tipologie di vegetazione presenti. Si riportano le specie vascolari fisionomicamente rilevanti e le specie con particolare valore conservazionistico
Development of a new GIS-based method to detect high natural value farmlands. A case study in central Italy
An original method for the identification of High Natural Value farmlands is presented. Gathering information about land use (CORINE Land Cover), geomorphology (elevation and Terrain Ruggedness Index) and remote sensing data in a GIS environment we were able to develop a new detection process; its application to a wide sector of central Italy, in areas characterized by high biodiversity and relevant agronomic and cultural value, is presented. Thus, a new tool for diminishing sampling efforts and economic and time wastes in territorial studies is provided
Risk assessment and profit sharing in business networks
Nowadays network is the preferred governance form to conduct economic transactions.
Network solution allows to reach flexibility maintaining cost and quality level. Since
network concept refers to a great variety of organizational hybrids it is possible to
choose the one that fits better market requirements. The new trends in interorganization
relationships push towards network solutions: companies are interested
in relationships with partners and customers to overcome resource dependence, to
enter too risky market or simply differentiate their business portfolio. The proposed
research focuses on the network concept aiming at highlighting threats and
opportunities to investigate the double nature of the risk concept. Network structures
offer flexibility and higher profit as a consequence and business risk sharing
opportunity.
These two aspects (profit and risk) are strictly related and have to be considered
together to depict a complete scenario; this implies that risk assessment and
management in network environment cannot neglect profit sharing or, in other words,
that profit sharing mechanisms should use risk as driver. In this context our research
proposes a methodology to measure risk taking into account network peculiarities; risk
estimation is a basic step to evaluate the opportunity cost of capital needed to compute
the network Net Present Value (NPV) that is assumed as base in the profit sharing
process. The profit sharing process has been tackled using the Shapley value approach
that is inspired to the fairness principle while the opportunity cost of capital is assessed
using the Capital Asset Pricing Model (CAPM)
La flora vascolare degli oliveti della Bassa Sabina (Lazio, Italia centrale)
L’olivo (Olea europaea L.) è una specie caratteristica degli aspetti più termofili della macchia mediterranea (Oleo-Ceratonion). La sua domesticazione è avvenuta presumibilmente già nel Neolitico, ad opera delle popolazioni del Medio Oriente; da qui, le varietà coltivate sarebbero arrivate prima ai Greci e poi agli Etruschi (Pignatti 2018). Oggi gli oliveti sono tra le coltivazioni più caratteristiche del paesaggio agricolo mediterraneo (Angles 1999); qui risultano spesso inseriti nelle aree agricole ad alto valore naturale tipiche dei territori rurali geomorfologicamente complessi (Fanfarillo et al. 2017a, 2017b). Gli appezzamenti ad olivo, in particolare quelli più antichi e a gestione estensiva, ospitano livelli considerevoli di biodiversità (Perrino, Veronico 2012, Marzano et al. 2013, Fanfarillo et al. 2018), motivo per cui ne è stato proposto l’inserimento tra gli habitat di interesse comunitario ai sensi della Direttiva 92/43/CEE (Biondi et al. 2007).
La Sabina è tra le zone dell’Italia centrale maggiormente vocate all’olivicoltura, in particolare nella parte meridionale, dove sui rilievi carbonatici rivolti verso il Mar Tirreno si configurano condizioni morfo-climatiche ideali per la crescita dell’olivo. L’area coincide con la zona di produzione dell’olio extravergine di oliva DOP “Sabina” (Commissione Europea 1996); in considerazione di ciò, gli oliveti occupano una posizione importante tra le tipologie di uso del suolo. Pertanto, nel corso dei mesi di aprile e maggio 2017 e 2018 è stata effettuata una campagna di rilevamento sulla flora e sulla vegetazione, ad oggi poco conosciute, che colonizzano queste coltivazioni arboree nella Bassa Sabina (prov. Rieti, Lazio); sono stati eseguiti 62 rilievi su plot di area fissa pari a 16 m2, superficie consigliata per il rilevamento delle comunità erbacee europee (Chytrý, Optyková 2003). Le colture indagate sono tutte a gestione tradizionale/estensiva, falciate e/o pascolate e non sottoposte a lavorazione del terreno (Fig. 1).
Complessivamente sono stati censiti 234 taxa di piante vascolari. La famiglia più rappresentata è risultata essere quella delle Fabaceae (36 taxa), seguita da Asteraceae (32) e Poaceae (31). Ben rappresentate sono anche le Brassicaceae, con 13 taxa; le altre famiglie hanno mostrato una consistenza inferiore. Sono state rinvenute tre specie rare nella regione Lazio secondo Anzalone et al. (2010): Glechoma hederacea L., Securigera cretica (L.) Lassen e Sisymbrium irio L.; tra le entità indicate dagli stessi autori come poco comuni nel territorio regionale, sono state censite Equisetum palustre Anemone coronaria L., Anthemis arvensis L. subsp. incrassata (Loisel.) Nyman, Ervum pubescens DC., Gladiolus byzantinus Mill., Ononis viscosa L. subsp. breviflora (DC.) Nyman, Trifolium squarrosum L. e Triticum neglectum (Req. ex Bertol.) Greuter. Alcuni di questi taxa poco diffusi sono stati rinvenuti per la prima volta in Sabina: ad essi si aggiungono l’alloctona casuale Brassica nigra (L.) W.D.J.Koch e il più comune Rhinanthus minor L., per un totale di nove entità di nuova segnalazione nell’area di studio. Di interesse è risultata la presenza di quattro specie di Orchidaceae, sia pur comuni in regione: Ophrys apifera Huds., Orchis italica Poir., Orchis purpurea Huds., e Serapias vomeracea (Burm.f.) Briq. Il contingente di specie alloctone (identificato secondo Galasso et al., 2018 e Bartolucci et al., 2018), si è rivelato estremamente ridotto, essendo costituito da appena 10 specie (2,3% del totale): sei archeofite (Arundo donax L. - l’unica invasiva - Avena fatua L., Avena sterilis L., Brassica nigra (L.) W.D.J.Koch, Galega officinalis L. e Medicago sativa L.) e quattro neofite (Crepis sancta (L.) Bornm. subsp. nemausensis (P.Fourn.) Babc., Erigeron canadensis L., Erigeron sumatrensis Retz., e Veronica persica Poir., le ultime tre invasive nel Lazio).
I rilievi sono stati sottoposti ad un’analisi di classificazione, che ha consentito di individuare tre gruppi dalla composizione floristica discretamente differenziata, caratterizzati da livelli decrescenti di disturbo antropico e da crescenti maturità strutturale e mesofilia. In termini strutturali (Fig. 2a) i tre gruppi di rilievi mostrano una graduale diminuzione dell’incidenza di Terofite dal gruppo 1 al gruppo 3, con il conseguente incremento delle specie perenni, ove le Emicriptofite risultano essere le maggiormente rappresentate, seguite dalle Geofite. Gli spettri corologici (Fig. 2b) rivelano una generale predominanza delle specie a distribuzione Eurimediterranea, evidenziando poche differenze tra i tre aspetti; a questo fa eccezione il contingente Cosmopolita, che risulta essere di gran lunga maggiore nel gruppo 1 rispetto ai gruppi 2 e 3, coerentemente con il minore disturbo antropico a cui questi ultimi sono presumibilmente sottoposti.
In conclusione l’indagine ha rivelato la presenza, all’interno dei contesti indagati, di una flora ricca e includente elementi di pregio naturalistico. Tali evidenze danno ulteriore conferma di come l’agricoltura estensiva sia di supporto alla diversità biologica, garantendo il mantenimento di habitat secondari indispensabili per la sopravvivenza di numerose specie vegetali e, di conseguenza, dei taxa animali ad esse legati
The anthropogenic grasslands of the Securigero securidacae-Dasypyrion villosi in central Mediterranean areas. Synecology, distribution and syntaxonomy
The anthropogenic therophitic grasslands dominated by tall Poaceae of Italy were recently included in the alliance Securigero securidacae-Dasypyrion villosi (Chenopodietea). Similar vegetation types from Sicily, Sardinia, Albania, and Greece were hypothesized to pertain to this syntaxon. In this work, we performed multivariate analyses on 493 phytosociological relevés certainly or likely ascribable to the alliance, gathering personal unpublished data and those available from literature. Our results confirm that this vegetation type has its core distribution in peninsular Italy, with irradiations in Sardinia and the lower Po Valley. Except for one relevé, similar communities from the Balkans were not includable in the Securigero-Dasypyrion, as well as others from the Italian Peninsula and Sicily. Based on our results, we describe the Mediterranean sub-alliance Securigero securidacae-Dasypyrenion villosi (including six vegetation types) and its Submediterranean vicarious Hordeo murini-Anisanthenion diandrae (including three vegetation types). Three new associations are described
Molecular dynamics simulation of a model oligomer for poly(N-isopropylamide) in water
Molecular dynamics (MD) has been used to simulate a dilute aqueous solution of a 50-units oligomer model for the thermoresponsive
polymer poly(N-isopropylacrylamide) at 300 and 310 K, i.e., below and above its lower critical solution temperature
(LCST) in water. Statistical analyses of the system trajectories show that at 310 K the oligomer exhibits a more compact conformation
than at 300 K, in qualitative agreement with experiments, and that it is surrounded by a smaller number of first-hydrationshell
water molecules
Circularly polarized luminescence of natural products lycorine and narciclasine: role of excited-state intramolecular proton-transfer and test of pH sensitivity
: Circularly polarized luminescence (CPL) is increasingly gaining interest not only for its applicative potentialities but also for providing an understanding of the excited state properties of chiral molecules. However, applications of CPL are mainly in the field of materials science: special organic molecules and polymers, metal (lanthanide) complexes, and organic dyes are actively and intensely studied. So far natural compounds have not been investigated much. We fill the gap here by measuring circular dichroism (CD) and CPL of lycorine and narciclasine, the most abundant known alkaloid and isocarbostyril from Amaryllidaceae, which exhibit a large spectrum of biological activities and are promising anticancer compounds. Dual fluorescence detection in narciclasine led us to unveil an occurring excited-state intramolecular proton transfer (ESIPT) process, this mechanism well accounts for the Stokes shift and CPL spectra observed in narciclasine. The same molecule is interesting also as a pH chiroptical switch. Both in absorption and emission, lycorine and narciclasine are also studied computationally via density functional theory (DFT) calculations further shedding light on their properties
Relations between morphological settings and vegetation covers in a medium relief landscape of Central Italy
Morphometric units and vegetation classes were determined by applying two classification methods to the Soratte Mount area, a medium relief structure within the Italian Latium region. The study aims at defining the relationships between vegetation and landform types and highlighting the main morphological characteristics within examined land cover classes. These were the result of the application of a supervised classification method to the first 28 (VIS-NIR) bands of the airborne MIVIS data collected within an extensive survey campaign over Rome Province. The analysis was supported by photo-interpretation of peculiar MIVIS band combinations and by data acquired during field surveys and from a pre-existing vegetation map. The morphometric data were obtained by processing a raster DEM created from topographic maps. These data were processed by means of a new morphometric classification method based on the statistical multivariate investigation of local topographic gradients, calculated along the 8 azimuth directions of each pixel neighbourhood. Such approach quickly estimates the spatial distribution of different types of homogeneous terrain units, emphasizing the impact of erosional and tectonic processes on the overall relief. Mutual relations between morphometric units and vegetation types were assessed by performing a correspondence analysis between the results of the two classifications
The weed vegetation of the bean “Fagiolo Cannellino di Atina” and the red pepper “Peperone di Pontecorvo” PDO crops (Latium, central Italy)
The weed vegetation of the bean “Fagiolo Cannellino di Atina” (Phaseolus vulgaris L.) and the red pepper “Peperone di Pontecorvo”
(Capsicum annuum L.) PDO (Protected Designation of Origin) crops was surveyed by means of 16 relevés, sampled in four farms of
southern Latium during July 2019. The relevés were subjected to multivariate analysis, which revealed that the two crops are weeded
by vegetation types referable to two different subassociations of Panico-Polygonetum persicariae (Spergulo-Erodion, Eragrostietalia,
Digitario-Eragrostietea). Namely, communities colonizing bean fields, which are more mesophilous and richer in Eurasian taxa, are
ascribable to the subassociation sorghetosum halepensis. Communities colonizing red pepper fields, which are more thermophilous
and richer in Mediterranean taxa, are ascribable to the subassociation cyperetosum rotundi. Floristic, structural, and chorological
features of the communities are discussed in relation to environmental factors and agricultural management
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