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| Cheek, M.; Feika, A.; Lebbie, A.; Goyder, D.; Tchiengue, B.; Sene, O.; Tchouto, P.; Burgt, X. van der. |
| Six new species of Inversodicraea (I. feika from Sierra Leone, I. liberia from Liberia, and I. ebo, I. eladii, I. tchoutoi, and I. xanderi from Cameroon) are described as new to science in the context of a synoptic revision of this African genus, now comprising 30 species, including I. cussetiana comb. nov., newly transferred from Macropodiella. Inversodicraea is now equal in number of species to Ledermanniella (as redefined), as the largest genus of the family in Africa. Terete or slightly dorsiventrally flattened leaf petioles (not sheathing and/or stipulate) are newly discovered to distinguish the genus from Ledermanniella, in addition to the presence of scale-leaves. Inversodicraea boumiensis, I. annithomae, and I. bosii are redelimited in this paper.... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Conservation; Extinction risk; Hybridisation; Hydroelectric dam projects; Rheophytes; Stage-dependent heteromorphy. |
| Ano: 2017 |
URL: http://www.repository.naturalis.nl/record/636690 |
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| Dunham, Jason; University of Nevada-Reno; jdunham@proaxis.com; Peacock, Mary; University of Nevada-Reno; mpeacock@scs.unr.edu; Tracy, C. Richard; University of Nevada-Reno; dtracy@unr.edu; Nielsen, Jennifer; Stanford University; jnielsen@leland.stanford.edu; Vinyard, Gary; University of Nevada-Reno; gvinyard@med.unr.edu. |
| Risks of population extinction have been estimated using a variety of methods incorporating information from different spatial and temporal scales. We briefly consider how several broad classes of extinction risk assessments, including population viability analysis, incidence functions, and ranking methods integrate information on different temporal and spatial scales. In many circumstances, data from surveys of neutral genetic variability within, and among, populations can provide information useful for assessing extinction risk. Patterns of genetic variability resulting from past and present ecological and demographic events, can indicate risks of extinction that are otherwise difficult to infer from ecological and demographic analyses alone. We provide... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Extinction risk; Genetic variation; Incidence function analysis; Population viability analysis; Ranking methods; Risk assessment; Spatial scale; Temporal scale.. |
| Ano: 1999 |
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| Brook, Barry W; Northern Territory University; barry.brook@ntu.edu.au; Burgman, Mark A; University of Melbourne; m.burgman@botany.unimelb.edu.au; Frankham, Richard; Macquarie University; rfrankha@rna.bio.mq.edu.au. |
| Population viability analysis (PVA) is used in conservation biology to predict extinction probabilities for threatened species. Previous studies have revealed large differences between the predictions of PVA modeling packages, but these comparisons included a range of nonstandard factors. A standardized comparison of five PVA packages (GAPPS, INMAT, RAMAS Metapop, RAMAS Stage, and VORTEX) was conducted on six examples (two mammals, two birds, one reptile, and a hypothetical bird/mammal-like life history). The individual-based packages (GAPPS and VORTEX) predicted a consistently higher risk of extinction than their matrix-based counterparts (INMAT and the RAMAS programs). This arose as only the former considered the effect of demographic stochasticity in... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Demographic stochasticity; Extinction risk; Individual-based models; Matrix-based models; Model comparison; Parameter estimation; Population viability analysis; Sex ratio. |
| Ano: 2000 |
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| Bertoni,Bianca Waléria; Souza,Ana Valéria de; Biondo,Ronaldo; França,Suzelei de C; Telles,Mariana PC; Pereira,Ana Maria S. |
| Mandevilla velutina (Mart. Ex Stadelm) Woodson (Apocynaceae) is an endemic species in the Cerrado (Brazilian Savannah), whose alcoholic extracts and root infusions are extensively used in the popular medicine to treat inflammatory diseases and against snake bites. Currently, this species has been pointed out as crucial in conservation programs. Therefore, studies on its genetic diversity, as well as the development of methodology for in vitro conservation in germplasm banks are imperative to avoid its extinction. The objective of this work was to investigate the intra- and inter-populational genetic variability of M. velutina to enhance the representativeness of germplasm banks. To this aim, we used RAPD molecular markers. The analysis of molecular... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mandevilla velutina; Medicinal plant; Extinction risk; Molecular markers. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362010000200012 |
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| Godoy-Bürki,Ana C.; Aagesen,Lone; Sajama,Jesús M.; Bravo,Silvia; Alonso-Pedano,Mariana; Ortega-Baes,Pablo. |
| In this study, 34 Cactaceae species from the Calchaquíes Valleys, Argentina, were studied to determine 1) species rarity level, 2) proportion of rare species among taxonomic and ecological groups and, 3) whether rareness is consistently distributed throughout the species geographical ranges. We used a model where rarity is defined by the geographic range and the local population size to define species rarity. Rareness was not concentrated in any particular taxonomic or ecological group of Cactaceae; however 28 species were rare at some level. In most species, rarity varied across the geographical range, only five species remained consistently rare in all the surveyed populations. Six species qualified as extremely rare, all from the Cactoideae subfamily,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geographic range; Local abundance; Extinction risk; Endemism. |
| Ano: 2016 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2016000100007 |
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