1,721,044 research outputs found
Alien plant species do have a clear preference for different land uses within urban environments
No full textSince neophytes can become invasive in the future, untangling their ecological preferences is of paramount importance, especially in urban areas where they represent a substantial proportion of the local flora. Studies exploring alien species assemblages in urban environments are however scarce. This study aims to unravel alien plant species preferences for five urban land uses (densely built-up areas, open built-up areas, industrial areas, broadleaved urban forests, and agricultural areas and small landscape elements). We took the city of Brussels as a model, in which we recorded all vascular species growing spontaneously in grid cells of 1 km2. We tested two different ways of classifying the 1-km2 cells: (1) We simply associated each cell with its dominant land cover; (2) We used a fuzzy approach for which the degree of association of a given cell to a given land cover depended on the proportion of that land cover within the cell. For both classification methods, we calculated the indicator species of the resulting land cover types based on alien species only. The crisp and fuzzy classifications identified 33 and 49 species, respectively, with a clear preference for some urban land use types (from a total of 129 alien plant species analyzed). Results showed that urban land use types having apparently similar environmental conditions can actually harbor different neophyte assemblages. Fine-tuning the categorization of urban environments in future ecological studies is therefore important for understanding spatial patterns of alien species occurrence
Assessing the magnitude and implications of seed germination changes during ex situ cultivation
No full textThe conservation of plants ex situ, i.e. in living collections or as seeds in seed banks, has become a central pillar in current global conservation efforts. The Global Strategy for Plant Conservation (GSPC) has set the ambitious target of safeguarding 75% of all endangered plants ex situ. This has resulted in a major boom of the ex situ conservation sector worldwide, and botanic gardens as major ex situ facilities, have strongly increased their investment in wild plant collections. There are currently more than 2,300 horticultural institutions such as botanic gardens, and over 350 professional seed banks worldwide storing and cultivating around 30% of known wild plant species (Donnell & Sharrock 2017; Mounce, Smith & Brockington 2017). While these numbers are impressive, there is not much knowledge about the quality of these collections, neither is there about how cultivation and seed storage can alter plant traits, and how these changes could affect the reintroduction success of an ex situ conserved specie
On farm plant reintroduction: A decision framework for plant conservation translocation in EU agro-ecosystems
No full textThe increased demand of food produced through sustainable agriculture has resulted in localised amelioration of
intensive management imposed by agroecosystems. However, these newly available niches are often isolated and
plant species may not be able to recolonise fragmented agroecosystems from where they have been extirpated.
Plant reintroduction can overcome dispersal limitation in agroecosystems but may also generate conflicts that
jeopardise conservation efforts. Conflicts arise when reintroductions are perceived to place constraints on the
management and productivity of agroecosystems: the translocated plants may require space sharing with crops,
may have negative effects on crop yields, and come with the expectation that farmers must modify their farming
practices and accommodate legal obligations deriving from protected species status. Benefits include economic
incentives that pay farmers through CAP, the conservation of nature, ecosystem services, an effective marketing
strategy and increased aesthetic value that might generate ecotourism.
We discuss the practical implications of the abovementioned issues by reference to two cases of European
species in which different approaches to reintroduction resulted in opposite outcomes (i.e., consensus vs. opposition).
Coexistence of threatened plants and crops is possible if farmers and local stakeholders are involved in
a conservation project from an early stage and if farmers conservation efforts turn into benefits for their income.
Based on these considerations, we propose a strategic framework to promote reintroduction of threatened plants
in agroecosystems (land sharing) and policy advancement aimed at recognising the role of farmers in maintaining
biodiversity on their lands
Computing diversity from dated phylogenies and taxonomic hierarchies: Does it make a difference to the conclusions?
No full textRecently, dated phylogenies have been increasingly used for ecological studies on community structure and conservation planning. There is, however, a major impediment to a systematic application of phylogenetic methods in ecology: reliable phylogenies with time-calibrated branch lengths are lacking for a large number of taxonomic groups and this condition is likely to continue for a long time. A solution for this problem consists in using undated phylogenies or taxonomic hierarchies as proxies for dated phylogenies. Nonetheless, little is known on the potential loss of information of these approaches compared to studies using dated phylogenies with time-calibrated branch lengths. The aim of this study is to ask how the use of undated phylogenies and taxonomic hierarchies biases a very simple measure of diversity, the mean pairwise phylogenetic distance between community species, compared to the diversity of dated phylogenies derived from the freely available software Phylomatic. This is illustrated with three sets of data on plant species sampled at different scales. Our results show that: (1) surprisingly, the diversity computed from dated phylogenies derived from Phylomatic is more strongly related to the diversity computed from taxonomic hierarchies than to the diversity computed from undated phylogenies, while (2) less surprisingly, the strength of this relationship increases if we consider only angiosperm specie
Plant evolutionary history is largely underrepresented in European seed banks
No full textConsidering the alarming prospect of at least two in five plant species facing extinction, it is urgent to identify unsecured phylogenetic branches within the plant Tree of Life and adopt appropriate conservation strategies. While conventional seed banking has the potential to safeguard a large part of world's flora, the scarcity of phylogenetically informed ex situ conservation programmes poses a challenge to effective plant conservation. Leveraging an extensive dataset of seed collections across 109 European seed banks, our study reveals that current collections capture a phylogenetically diverse subset of the European flora. However, they safeguard between 43.29% and 66.40% of the maximum possible phylogenetic diversity, suggesting that specific major branches of the plant phylogeny in Europe remain unprotected. To address this gap, we introduce a novel quasi-deterministic method to generate a list of unbanked species, prioritized by evolutionary significance. Although this approach can enhance the evolutionary quality of seed bank collections, biological, technical and practical constraints may limit conventional seed banking for some of these priority species. We advocate for an enhanced coordination among conservation facilities and the integration of phylogenetic perspectives with advancements in ex situ conservation techniques beyond conventional seed banking, to effectively conserve plant evolutionary heritage.Screening of European seed banks and dissemination of the survey were facilitated by networking activities organized by the EU COST Action CA18201 – An integrated approach to conservation of threatened plants for the 21st Century (ConservePlants), supported by COST (European Cooperation in Science and Technology). We are grateful to all researchers and institutions that have contributed to the seed bank dataset (see Table S1). We also thank the University of Pisa, the Scientific Computation Centre of Andalusia (CICA) for their crucial computing services, and the Spanish Ministry of Science, Innovation, and Universities for supporting the research through the grant PID2022-138776NA-I00.Peer reviewe
Plant evolutionary history is largely underrepresented in European seed banks
No full textData and phylogenetic trees used to conduct the phylogenetic assessment of European conservation seed bank collectionsPeer reviewe
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
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