1,724,032 research outputs found
Ruolo di fattori biotici ed abiotici nella dinamica del P all’interfaccia acqua-sedimento: un’analisi multicompartimentale.
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Role of induced perturbations and detritivorous crustaceans density in decomposition process.
No full textStruttura della fascia costiera lacustre e processo di decomposizione nel corpo d’acqua: un approccio all’uso del remote sensing nell’indagine funzionale in ecologia.
No full textA global occurrence database of the Atlantic blue crab Callinectes sapidus
Full text linkThe Atlantic blue crab Callinectes sapidus is a portunid native to the western Atlantic, from New England to Uruguay. The species was introduced in Europe in 1901 where it has become invasive; additionally, a significant northward expansion has been emphasized in its native range. Here we present a harmonized global compilation of C. sapidus occurrences from native and non-native distribution ranges derived from online databases (GBIF, BISON, OBIS, and iNaturalist) as well as from unpublished and published sources. The dataset consists of 40,388 geo-referenced occurrences, 39,824 from native and 564 from non-native ranges, recorded in 53 countries. The implementation of quality controls imposed a severe reduction, in particular from online databases, of the records selected for inclusion in the dataset. In addition, a technical validation procedure was used to flag entries showing identical coordinates but different year of record, in-land occurrences and those located close to the coast. Similarly, a flagging system identified entries outside the known distribution of the species, or associated with unsuccessful introductions
Carbon budget and national gross domestic product in the framework of the Paris Climate Agreement
Full text linkIn 2015 an unprecedented effort was made in Paris by the countries adhering to the United Nations Framework Convention on Climate Change to decrease the CO2 emissions due to the close relationships of greenhouse gases with global warming. Under the previous Kyoto Protocol, only advanced countries were committed to reduce greenhouse emissions while under the Paris Climate Agreement all countries were committed to fight against global warming. The urgency of real action has been prompted by extreme events like bushfires, heatwaves, and the ongoing pandemic. Given the strong commitments, it looks interesting, seen that all countries are involved, to verify if any sustainability pattern is evident. Our approach is encouraging, as the downward emission trend shows a high increase in sustainability between 2027 and 2037. Without exacerbating the climate discussion, we used the national gross domestic product (hereafter: GDP) as environmental indicator to propose for the first time an allometric ranking of countries that need to change drastically their energy policy to meet their climate commitments. Any sustainability downturn in one country, especially if advanced, might rationally bring concern about the actual prospects of other countries which are all committed to the Paris Climate Agreement. But the departure from the annual allometric model GDP−CO2 may be much greater than can be accounted for by statistical expectations, as for Ukraine, Uzbekistan and Turkmenistan that are entering a sustainable condition where their CO2 emissions will be lower than they would have been without the Paris Climate Agreement
Species richness and taxonomic distinctness of zooplankton in ponds and small lakes from Albania and North Macedonia: The role of bioclimatic factors
Full text linkResolving the contribution to biodiversity patterns of regional-scale environmental drivers is, to date, essential in the implementation of effective conservation strategies. Here, we assessed the species richness S and taxonomic distinctness Δ+ (used a proxy of phylogenetic diversity) of crustacean zooplankton assemblages from 40 ponds and small lakes located in Albania and North Macedonia and tested whether they could be predicted by waterbodies' landscape characteristics (area, perimeter, and altitude), together with local bioclimatic conditions that were derived fromWordclim and MODIS databases. The results showed that a minimum adequate model, including the positive effects of non-arboreal vegetation cover and temperature seasonality, together with the negative influence of the mean temperature of the wettest quarter, effectively predicted assemblages' variation in species richness. In contrast, taxonomic distinctness did not predictably respond to landscape or bioclimatic factors. Noticeably, waterbodies' area showed a generally low prediction power for both S and D+. Additionally, an in-depth analysis of assemblages' species composition indicated the occurrence of two distinct groups of waterbodies characterized by different species and different precipitation and temperature regimes. Our findings indicated that the classical species-area relationship hypothesis is inadequate in explaining the diversity of crustacean zooplankton assemblages characterizing the waterbodies under analysis. In contrast, local bioclimatic factors might affect the species richness and composition, but not their phylogenetic diversity, the latter likely to be influenced by long-term adaptation mechanisms
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
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