1,721,022 research outputs found
Community weighted mean trait data of Italian forest understories
Full text linkPlant functional trait data aggregated at the community level (i.e., community weighted mean, CWM) are fundamental to study plant-environment relationships. Here, we provide a large database of CWM values of twelve traits reflecting several plant functions, including leaf, seed, whole-plant, clonal and bud bank traits. The CWMs were calculated in 201 forest stands (a statistically representative sample of all the Italian forests) across three biogeographic regions: Alpine, Continental, and Mediterranean. © 2019 The Author(s
Towards the establishment of the Italian network of old-growth forests: the understorey plant diversity perspective
Full text linkThe publication of the Decree that has established the Italian network of old-growth forests opens new opportunities for nature conservation and new challenges for scientists. A fundamental criterion for the identification of old-growth forests is related to a “characteristic biodiversity” due to the absence of disturbances for at least sixty years. In this contribution we mainly discuss shortcomings, potential interpretation and perspectives related to the application of this criterion for the vascular plants living in the understorey. We show that the understorey diversity (both taxonomic and functional) patterns with forest maturity are strongly context-dependent and stand structural features are fundamental drivers. As a consequence, considering the impressive heterogeneity of Italian forests, the strict threshold included in the Decree (sixty years since the last disturbance) can hardly be used to distinguish a “characteristic biodiversity”. Finally, we invite all the Italian scientists dealing with forest ecosystems to strongly collaborate in order to accept the challenge introduced by the Decree
Unimodal relationships of understory alpha and beta diversity along chronosequence in coppiced and unmanaged beech forests
Full text linkPatterns of diversity across spatial scales in forest successions are being overlooked, despite their importance for developing sustainable management practices. Here, we tested the recently proposed U-shaped biodiversity model of forest succession. A chronosequence of 11 stands spanning from 5 to 400 years since the last disturbance was used. Understory species presence was recorded along 200 m long transects of 20 X 20 cm quadrates. Alpha diversity (species richness, Shannon and Simpson diversity indices) and three types of beta diversity indices were assessed at multiple scales. Beta diversity was expressed by a) spatial compositional variability (number and diversity of species combinations), b) pairwise spatial turnover (between plots Sorensen, Jaccard, and Bray-Curtis dissimilarity), and c) spatial variability coefficients (CV% of alpha diversity measures). Our results supported the U-shaped model for both alpha and beta diversity. The strongest differences appeared between active and abandoned coppices. The maximum beta diversity emerged at characteristic scales of 2 m in young coppices and 10 m in later successional stages. We conclude that traditional coppice management maintains high structural diversity and heterogeneity in the understory. The similarly high beta diversities in active coppices and old-growth forests suggest the presence of microhabitats for specialist species of high conservation value
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
La biodiversità forestale: specie vegetali.
No full textIl monitoraggio dello stato di salute delle foreste nacque nella seconda metà degli anni ’80, nell’ambito della Convenzione sull’Inquinamento Transfrontaliero a Grande Distanza (Convention on Long Range Transboundary Air pollution, CLRTAP), attuata sotto l’egida della Commissione Economica per l’Europa delle Nazioni Unite (United Nations Economic Commission for Europe, UN/ECE). Per dare attuazione alla Convenzione, furono avviati diversi programmi operativi internazionali, tra i quali il Programma Cooperativo Internazionale sul monitoraggio integrato degli effetti dell’inquinamento atmosferico (International Cooperative Programme on Integrated Monitoring of Air Pollution Effects, ICP IM) ed il Programma Cooperativo Internazionale sulla valutazione ed il monitoraggio degli effetti dell’inquinamento atmosferico sulle foreste (International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests, ICP Forests). Il “Programma CON.ECO.FOR.” (CONtrollo ECOsistemi FORestali) rappresenta il ramo istituzionale italiano degli adempimenti derivanti dalle iniziative internazionali citate. La Rete NEC Italia, così come disegnata nel decreto del Ministero della Transizione Ecologica (a seguire MiTE) 26 novembre 2018, n. 319, attuativo del Decreto legislativo di recepimento della Direttiva, si basa sul monitoraggio degli impatti negativi di inquinanti atmosferici quali il biossido di zolfo, gli ossidi di azoto, i composti organici volatili non metanici, l’ammoniaca, il PM 2,5 , il PM 10 e l’ozono: • sugli ecosistemi terrestri, impiegando n°6 aree CON.ECO.FOR. di livello II e il relativo protocollo ICP Forests, dove l’Arma dei Carabinieri partecipa al lavoro dei ricercatori dell’Università di Firenze e di Camerino oltre a quelli del CNR e del CREA; • sugli ecosistemi di acqua dolce, impiegando n°10 siti ICP WATERS gestiti dal Consiglio Nazionale delle Ricerche CNR-IRSA, secondo le modalità di campionamento ed analisi previste dal protocollo ICP Waters; • dei danni da ozono, utilizzando i dati monitorati dal Consiglio Nazionale delle Ricerche CNR-IRET, in n° 11 stazioni forestali, selezionate per coprire sia ambienti diversi con la stessa specie forestale (il faggio, Fagus sylvatica L.), sia specie forestali temperate e mediterranee
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
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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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