3,807 research outputs found
Glass eel swimming curves - Vezza et al. 2020
No full textSwimming performance of European eel (Anguilla anguilla) in its juvenile, early life stage (glass eel). The dataset reports swimming curves that were derived by processing data obtained from flume experiments and Computational Fluid Dynamics (CFD) simulations. The dataset refers to the paper of Vezza et al. (2020) published in Scientific Reports (see references). The study (i) accommodates glass eel burst-and-coast swimming mode and estimates the active swimming time (tac), not considering coast and drift periods, (ii) estimates near-bottom velocities (Ub) experienced by the fish, rather than using bulk averages (U), (iii) investigates water temperature (T) influence on swimming ability.</span
Glass eel swimming curves - Vezza et al. 2020
No full textSwimming performance of European eel (Anguilla anguilla) in its juvenile, early life stage (glass eel). The dataset reports swimming curves that were derived by processing data obtained from flume experiments and Computational Fluid Dynamics (CFD) simulations. The dataset refers to the paper of Vezza et al. (2020) published in Scientific Reports (see references). The study (i) accommodates glass eel burst-and-coast swimming mode and estimates the active swimming time (tac), not considering coast and drift periods, (ii) estimates near-bottom velocities (Ub) experienced by the fish, rather than using bulk averages (U), (iii) investigates water temperature (T) influence on swimming ability
Meso-scale habitat description in the Gaià River (Tarragona, Spain)
No full textThis dataset represents a first attempt of meso-scale habitat modellig in temporary streams. In particular the dataset shows how habitat changes with flow and when water flows cease, defining the so-called "habitat-flow-time rating curve". Data were collected in the Gaià River (Tarragona Province, Iberian Peninsula) during both flow and non-flow phases. Multiple, stage-dependent surveys of geomorphological units provided basic maps for the characterization of mesohabitats in a reach located close to the El Catllar village. Following the MesoHABSIM model protocol (Vezza et al., 2014), these surveys were used to calculate spatio-temporal variation of habitat availability and draw curves that represent the relationship between discharge/zero flow days and (i) wet area, (ii) suitability habitat of key species, and (iii) connectivity . The level of each variable can also be represented in a percentage of its maximum level.
As an example, an autochthonous fish species (European eel) was used as an ecological target. Rating curves were developed between habitat and flow, and habitat and time quantified habitat availability for fish species in space (% of channel area) during both flow and non-flow phases
Motivi letterari nei libri per l’infanzia di Paolo Di Paolo
No full textThe article, organised in the form of a discussion, aims to analyse the themes and motifs of Paolo Di Paolo’s works that are addressed to young audiences. The author has recently published a large number of volumes directed just at younger readers. When beholding the titles that constitute the author’s bibliography, the reader is struck by Di Paolo’s predisposition to transform literary classics: as much in Giacomo il signor bambino as in the edition of the Divina Commedia, the author’s goal is to try to reach his new readers. Therefore, Di Paolo proves to be a prolific author of the genre; in fact, in his bibliography, volumes of fairy tales with a classic slant, such as La mucca volante, are listed as well.L’articolo contiene un’analisi di temi e di motivi delle opere di Paolo Di Paolo dirette al pubblico più piccolo. L’autore negli ultimi anni ha pubblicato un cospicuo numero di volumi indirizzati, infatti, proprio ai lettori più giovani. Ciò che stupisce scorgendo i titoli che costituiscono la bibliografia dell’autore, è la predisposizione a trasformare i classici della letteratura: tanto in Giacomo il signor bambino quanto nell’edizione della Divina Commedia l’obiettivo è cercare di raggiungere i lettori più giovani. Di Paolo si dimostra, quindi, un autore prolifico del genere, tant’è che nell’elenco non mancano volumi fiabeschi dal taglio classico come La mucca volante. Analizzare le opere giovanili dello scrittore costituisce un fatto inedito
Eco-morphodynamic carbon pumping by the largest rivers in the Neotropics
No full textThe eco-morphodynamic activity of large tropical rivers in South and Central America is analyzed to quantify the carbon flux from riparian vegetation to inland waters. We carried out a multi-temporal analysis of satellite data for all the largest rivers in the Neotropics (i.e, width > 200 m) in the period 2000–2019, at 30 m spatial resolution. We developed a quantification of a highly efficient Carbon Pump mechanism. River morphodynamics is shown to drive carbon export from the riparian zone and to promote net primary production by an integrated process through floodplain rejuvenation and colonization. This pumping mechanism alone is shown to account for 8.9 million tons/year of carbon mobilization in these tropical rivers. We identify signatures of the fluvial eco-morphological activity that provide proxies for the carbon mobilization capability associated with river activity. We discuss river migration—carbon mobilization nexus and effects on the carbon intensity of planned hydroelectric dams in the Neotropics. We recommend that future carbon-oriented water policies on these rivers include a similar analysis.PL-LCH[1402
Quantitative habitat models for the conservation of the endangered European crayfish Austropotamobius pallipes complex (Astacoidea: Astacidae)
No full textCrayfish are the largest mobile freshwater invertebrates and are keystone species in European aquatic ecosystems particularly in small streams and rivers. The white-clawed crayfish Austropotamobius pallipes (a species complex) is currently classified by the IUCN Red List as an endangered species (EN), because its populations have decreased significantly over the last decades in a number of European countries including Italy, due mainly to habitat modifications and the introduction and spread of alien species. Data on the ecological requirements of A. pallipes are needed to quantify the effects of habitat alteration, to simulate restoration scenarios, and to implement effective conservation measures for this species. We describe here a new methodology for modelling the habitat requirements for this endangered crayfish using the mesohabitat scale approach based on data from crayfish living in small streams draining the Italian foothills of the Alps (Lombardy region) and in streams in the mountainous areas of the Gran Sasso and Monti della Laga National Park (Abruzzo region). Data from seven morphologically different streams were used to train and validate the habitat models. The Random Forests algorithm was used to identify the best and most parsimonious habitat model, and to define the lowest number of variables to be surveyed in the future. The best habitat models were applied to each stream and used to classify each mesohabitat into suitability categories. Habitat flow-rating curves were developed to analyze spatio-temporal variation of habitat availability, and habitat time series analysis were used to define detailed management schemes for environmental river management. Flow releases and water temperature regimes were assessed for individual water diversions in order (1) to represent how physical habitat changes through time, and (2) to identify stress conditions for A. pallipes created by the persistent limitation of habitat availability. Results indicated that the kind of substrate in the stream bed (such as the proportion of fine-grained substrates), the water depth (whether shallow or deep), and the available cover (such as the presence of boulders, woody debris, and undercut banks) were all significant factors governing the occurrence of crayfish. The habitat models performed well in both calibration and validation phases (with accuracy ranging from 71% to 79% in training and from 69% to 73% in validation) and can be considered to be a valuable tool to predict the distribution of A. pallipes over a wide range of stream types. An example of how to establish environmental standards for small streams is presented. The proposed habitat model provides a useful tool that can be applied even when other commonly used methodologies are unsuitable. As such, this habitat model can be used to develop regional rules for the conservation of the endangered crayfish A. pallipes complex and for defining more site-specific management criteria
Small catchments environmental flows assessment at regional scale: the case study of Piedmont Region (NW Italy)
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