1,720,956 research outputs found
Ground beetle assemblages (Coleoptera, Carabidae) as indicators of succession in the Trstenik bog
No full textCretovi su specifična močvarna staništa na kojima često glavnu ulogu imaju mahovine. Opstanak creta Trstenik ugrožen je zbog sukcesije vegetacije i isušivanja creta. U ovom su istraživanju kao indikatori promjena na cretu korišteni trčci (Carabidae). Ciljevi istraživanja bili su odrediti razlike u sastavu i strukturi zajednica trčaka na tri staništa na cretu Trstenik (središnjem i sukcesijskom dijelu creta te šumskom rubu), odrediti utjecaj okolišnih čimbenika na prostornu raspodjelu trčaka te definirati mjere očuvanja creta. Trčci su sakupljani metodom lovnih posuda od lipnja do listopada 2021. godine. Ukupno su sakupljene 44 vrste i 1551 jedinka trčaka. Bogatstvo vrsta, brojnost jedinki te indeksi raznolikosti i ujednačenosti zajednica trčaka bili su najmanji u središtu creta, ali se nisu statistički značajno razlikovali od parametara u sukcesijskom dijelu creta, dok su na šumskom rubu zabilježene statistički značajno više vrijednosti u odnosu na ostala istraživana staništa. Na cretu su najveći utjecaj na sastav zajednica trčaka imali povećana zastupljenost prizemnog sloja rašća i povišene vrijednosti temperature tla te, osobito u središnjem dijelu creta, povišena vlažnost i pH vrijednost tla, a na šumskom rubu povećana zastupljenost sloja drveća. Rezultati istraživanja upućuju na uznapredovali proces sukcesije u središnjem dijelu creta, no pronalazak indikatorskih vrsta trčaka ukazuje na postojanje uvjeta tipičnih za cretna staništa te su predložene mjere za obnavljanje staništa.Peat bogs are specific wetland habitats where mosses often play an important role. The Trstenik peat bog is threatened by vegetation succession and drying of the peat bog. In this study, ground beetles (Carabidae) were used as indicators of habitat changes. The objectives of this study were: i) to determine differences in the composition and structure of ground beetle communities in three habitats on the Trstenik peat bog, ii) to determine the influence of environmental factors on the spatial distribution of ground beetles, iii) to define peat bog conservation measures. Ground beetles were collected using pitfall traps. A total of 44 species and 1551 individuals were collected. All measured indices of ground beetle communities were lowest in the central part of the bog but did not differ significantly from the parameters in the successional part. Conversely, significantly higher values were recorded at the forest edge compared to the other two studied habitats. In the peat bog, the greatest impact on the composition of ground beetle communities had the increased presence of the herb layer and soil temperature values, and, particularly in the central part, increased soil moisture and pH. At the forest edge, the abundance of the tree layer played a significant role. The results of the study indicate progressive vegetation succession in the central part of the peat bog, but the discovery of indicator ground beetle species suggests the existence of typical peat bog conditions. Therefore, measures for habitat restoration are proposed
Ground beetle assemblages (Coleoptera, Carabidae) as indicators of succession in the Trstenik bog
No full textCretovi su specifična močvarna staništa na kojima često glavnu ulogu imaju mahovine. Opstanak creta Trstenik ugrožen je zbog sukcesije vegetacije i isušivanja creta. U ovom su istraživanju kao indikatori promjena na cretu korišteni trčci (Carabidae). Ciljevi istraživanja bili su odrediti razlike u sastavu i strukturi zajednica trčaka na tri staništa na cretu Trstenik (središnjem i sukcesijskom dijelu creta te šumskom rubu), odrediti utjecaj okolišnih čimbenika na prostornu raspodjelu trčaka te definirati mjere očuvanja creta. Trčci su sakupljani metodom lovnih posuda od lipnja do listopada 2021. godine. Ukupno su sakupljene 44 vrste i 1551 jedinka trčaka. Bogatstvo vrsta, brojnost jedinki te indeksi raznolikosti i ujednačenosti zajednica trčaka bili su najmanji u središtu creta, ali se nisu statistički značajno razlikovali od parametara u sukcesijskom dijelu creta, dok su na šumskom rubu zabilježene statistički značajno više vrijednosti u odnosu na ostala istraživana staništa. Na cretu su najveći utjecaj na sastav zajednica trčaka imali povećana zastupljenost prizemnog sloja rašća i povišene vrijednosti temperature tla te, osobito u središnjem dijelu creta, povišena vlažnost i pH vrijednost tla, a na šumskom rubu povećana zastupljenost sloja drveća. Rezultati istraživanja upućuju na uznapredovali proces sukcesije u središnjem dijelu creta, no pronalazak indikatorskih vrsta trčaka ukazuje na postojanje uvjeta tipičnih za cretna staništa te su predložene mjere za obnavljanje staništa.Peat bogs are specific wetland habitats where mosses often play an important role. The Trstenik peat bog is threatened by vegetation succession and drying of the peat bog. In this study, ground beetles (Carabidae) were used as indicators of habitat changes. The objectives of this study were: i) to determine differences in the composition and structure of ground beetle communities in three habitats on the Trstenik peat bog, ii) to determine the influence of environmental factors on the spatial distribution of ground beetles, iii) to define peat bog conservation measures. Ground beetles were collected using pitfall traps. A total of 44 species and 1551 individuals were collected. All measured indices of ground beetle communities were lowest in the central part of the bog but did not differ significantly from the parameters in the successional part. Conversely, significantly higher values were recorded at the forest edge compared to the other two studied habitats. In the peat bog, the greatest impact on the composition of ground beetle communities had the increased presence of the herb layer and soil temperature values, and, particularly in the central part, increased soil moisture and pH. At the forest edge, the abundance of the tree layer played a significant role. The results of the study indicate progressive vegetation succession in the central part of the peat bog, but the discovery of indicator ground beetle species suggests the existence of typical peat bog conditions. Therefore, measures for habitat restoration are proposed
Non-native species of ponto-caspian gobies in Croatia
No full textAlohtone vrste pojavljuju se van svog prirodnog područja rasprostranjenosti, a namjerno su ili slučajno prenesene u novo stanište. Alohtone vrste ponto-kaspijskih glavoča (porodica Gobiidae) prisutne u Hrvatskoj su glavočić okrugljak (Neogobius melanostomus), riječni glavoč (Neogobius fluviatilis), keslerov glavočić (Ponticola kessleri) i glavočić trkač (Babka gymnotrachelus). Prirodno su rasprostranjeni u području Azovskog, Crnog i Kaspijskog mora te donjim i srednjim tokovima rijeka koje se u njih ulijevaju. U gotovo sve zemlje sjeverne i središnje Europe proširili su se rijekama i povezanim vodenim putovima. U Hrvatskoj su rasprostranjeni u dunavskom slijevu, osobito u Dunavu i donjim tokovima rijeka koje se u njega ulijevaju. Predstavljaju prijetnju velikoj raznolikosti autohtonih slatkovodnih ribljih vrsta u Hrvatskoj. Ponto-kaspijski glavoči vrlo se dobro i brzo prilagođavaju novom staništu. Kompeticija za hranu i stanište, predacija na ribljim jajašcima, ličinkama i juvenilnim jedinkama te manjim vrstama riba mogući su uzroci negativnog utjecaja ponto-kaspijskih glavoča na autohtone vrste. Rezultati provedene FISK (eng. Fish Invasiveness Scoring Kit) analize za Hrvatsku pokazuju kako je glavočić okrugljak visoko rizična invazivna vrsta, a riječni glavoč, keslerov glavočić i glavočić trkač umjereno su do visoko rizične invazivne vrste. Kako bi se pratio utjecaj alohtonih vrsta ponto-kaspijskih glavoča na autohtone vrste, potreban je stalan monitoring ribljih zajednica slatkovodnih ekosustava.Non-native species appear outside their natural habitat, where they have been either intentionally or accidentally transferred to. Non-native species of Ponto-Caspian gobies (family Gobiidae) present in Croatia are the round goby (Neogobius melanostomus), monkey goby (Neogobius fluviatilis), bighead goby (Ponticola kessleri) and racer goby (Babka gymnotrachelus). They are naturally distributed throughout the Azov, Black and Caspian Sea as well as the lower and middle reaches of the rivers that flow into them. They spread to almost all countries of northern and central Europe by rivers and connected waterways. In Croatia, they are widespread in the Danube basin, especially in the river Danube and the lower reaches of the rivers that flow into it. They pose a threat to the great diversity of native freshwater fish species in Croatia. Ponto-Caspian gobies adapt very well and quickly to a new habitat. Competition for food and habitat, preying on fish eggs, larvae, juveniles, and smaller fish species are possible causes of the negative impact of Ponto-Caspian gobies on native species. The results of the FISK (Fish Invasiveness Scoring Kit) analysis for Croatia show that the round goby is a high-risk invasive species, while the monkey goby, bighead goby, and racer goby are moderate to high-risk invasive species. To monitor the impact of non-native species of Ponto-Caspian gobies onto native species, continuous monitoring of fish communities in freshwater ecosystems is neede
Ground beetle assemblages (Coleoptera, Carabidae) as indicators of succession in the Trstenik bog
No full textCretovi su specifična močvarna staništa na kojima često glavnu ulogu imaju mahovine. Opstanak creta Trstenik ugrožen je zbog sukcesije vegetacije i isušivanja creta. U ovom su istraživanju kao indikatori promjena na cretu korišteni trčci (Carabidae). Ciljevi istraživanja bili su odrediti razlike u sastavu i strukturi zajednica trčaka na tri staništa na cretu Trstenik (središnjem i sukcesijskom dijelu creta te šumskom rubu), odrediti utjecaj okolišnih čimbenika na prostornu raspodjelu trčaka te definirati mjere očuvanja creta. Trčci su sakupljani metodom lovnih posuda od lipnja do listopada 2021. godine. Ukupno su sakupljene 44 vrste i 1551 jedinka trčaka. Bogatstvo vrsta, brojnost jedinki te indeksi raznolikosti i ujednačenosti zajednica trčaka bili su najmanji u središtu creta, ali se nisu statistički značajno razlikovali od parametara u sukcesijskom dijelu creta, dok su na šumskom rubu zabilježene statistički značajno više vrijednosti u odnosu na ostala istraživana staništa. Na cretu su najveći utjecaj na sastav zajednica trčaka imali povećana zastupljenost prizemnog sloja rašća i povišene vrijednosti temperature tla te, osobito u središnjem dijelu creta, povišena vlažnost i pH vrijednost tla, a na šumskom rubu povećana zastupljenost sloja drveća. Rezultati istraživanja upućuju na uznapredovali proces sukcesije u središnjem dijelu creta, no pronalazak indikatorskih vrsta trčaka ukazuje na postojanje uvjeta tipičnih za cretna staništa te su predložene mjere za obnavljanje staništa.Peat bogs are specific wetland habitats where mosses often play an important role. The Trstenik peat bog is threatened by vegetation succession and drying of the peat bog. In this study, ground beetles (Carabidae) were used as indicators of habitat changes. The objectives of this study were: i) to determine differences in the composition and structure of ground beetle communities in three habitats on the Trstenik peat bog, ii) to determine the influence of environmental factors on the spatial distribution of ground beetles, iii) to define peat bog conservation measures. Ground beetles were collected using pitfall traps. A total of 44 species and 1551 individuals were collected. All measured indices of ground beetle communities were lowest in the central part of the bog but did not differ significantly from the parameters in the successional part. Conversely, significantly higher values were recorded at the forest edge compared to the other two studied habitats. In the peat bog, the greatest impact on the composition of ground beetle communities had the increased presence of the herb layer and soil temperature values, and, particularly in the central part, increased soil moisture and pH. At the forest edge, the abundance of the tree layer played a significant role. The results of the study indicate progressive vegetation succession in the central part of the peat bog, but the discovery of indicator ground beetle species suggests the existence of typical peat bog conditions. Therefore, measures for habitat restoration are proposed
Going 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
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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