Institut für Ökologie, Evolution und Diversität
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All giraffe (Giraffa) were previously assigned to a single species (G. camelopardalis) and nine subspecies. However, multi‐locus analyses of all subspecies have shown that there are four genetically distinct clades and suggest four giraffe species. This conclusion might not be fully accepted due to limited data and lack of explicit gene flow analyses. Here, we present an extended study based on 21 independent nuclear loci from 137 individuals. Explicit gene flow analyses identify less than one migrant per generation, including between the closely related northern and reticulated giraffe. Thus, gene flow analyses and population genetics of the extended dataset confirm four genetically distinct giraffe clades and support four independent giraffe species. The new findings support a revision of the IUCN classification of giraffe taxonomy. Three of the four species are threatened with extinction, and mostly occurring in politically unstable regions, and as such, require the highest conservation support possible.
The use of phylogenies in ecology is increasingly common and has broadened our understanding of biological diversity. Ecological sub-disciplines, particularly conservation, community ecology and macroecology, all recognize the value of evolutionary relationships but the resulting development of phylogenetic approaches has led to a proliferation of phylogenetic diversity metrics. The use of many metrics across the sub-disciplines hampers potential meta-analyses, syntheses, and generalizations of existing results. Further, there is no guide for selecting the appropriate metric for a given question, and different metrics are frequently used to address similar questions. To improve the choice, application, and interpretation of phylo-diversity metrics, we organize existing metrics by expanding on a unifying framework for phylogenetic information.
Generally, questions about phylogenetic relationships within or between assemblages tend to ask three types of question: how much; how different; or how regular? We show that these questions reflect three dimensions of a phylogenetic tree: richness, divergence, and regularity. We classify 70 existing phylo-diversity metrics based on their mathematical form within these three dimensions and identify ‘anchor’ representatives: for α-diversity metrics these are PD (Faith's phylogenetic diversity), MPD (mean pairwise distance), and VPD (variation of pairwise distances). By analysing mathematical formulae and using simulations, we use this framework to identify metrics that mix dimensions, and we provide a guide to choosing and using the most appropriate metrics. We show that metric choice requires connecting the research question with the correct dimension of the framework and that there are logical approaches to selecting and interpreting metrics. The guide outlined herein will help researchers navigate the current jungle of indices.
In Benin, people have a rich ethnobotanical knowledge of plant species, reflecting the cultural and ecological diversity of their environment. Several studies were focused on the question of how valuable are plant species for local communities. However, there has been very little research interest in the orchid species in spite of the importance of orchids in the livelihood of the local people. This study examined the use and differences in knowledge of local people of orchids in the Sudanian zone of Benin. An ethnobotanical study was conducted amongst the four main socio-economic and ethnic groups from six villages around the Pendjari Biosphere Reserve in Benin. One hundred and sixty people participated in this study. Data were gathered using semi-structured individual interviews and analysed using quantitative ethnobotanical methods. 29 different types of use were recorded and can be grouped into four main use categories: medicinal, veterinary, spiritual and food. There were differences in orchid utilization among the ethnic groups, gender and age. The knowledge of orchid uses was significantly affected by the ethnic group and the age of the respondent. Unlike young educated generations, most adults and elders, especially women, had a more comprehensive knowledge of orchid uses. Calyptrochilum christianum, the most used orchid, was mentioned in more than 50% of the types of orchid use. The Gourmantché and Waama tribe had more knowledge on orchid use whereas the Berba tribe had less knowledge. Three orchid species (Habenaria cirrhata, Eulophia horsfallii and Nervilia bicarinata) were reported as food. Orchids had low use value ranging from 0.01 (Eulophia spp) to 0.2 (C. christianum). The controlled access to the biosphere reserve and rural exodus can explain the lack of indigenous knowledge transfer of orchid use and value from elders to the young generation.
Les résultats de 227 relevés phytosociologiques selon l’approche phytosociologique effectuées au Parc Urbain Bangr-Wéoogo de Braun-Blanquet (1932) montrent que malgré son contexte de forte pression anthropique avec plus d´un million d’habitants aux alentours, cette forêt urbaine conserve encore de nos jours une diversité floristique appréciable avec 327 espèces inventoriées comprenant 117 espèces ligneuses et 210 espèces herbacées. Cette flore qui est répartie dans 11 groupements individualisés grâce aux espèces différentielles, est constituée essentiellement de phanérophytes et de thérophytes. La répartition phytogéographique des espèces montre leur appartenance à plusieurs empires phytogéographiques dominés par les espèces Soudano-Zambeziennes et Pantropicales. La richesse floristique du parc qui contraste avec son environnement, est le résultat d’une politique d’aménagement et de conservation efficace de la biodiversité initiée par l'État et ses partenaires depuis 1936. Mots clés: Flore, conservation, aménagement, spectre biologique, Parc Urbain, Ouagadougou, Burkina Faso, groupements végétaux