Darbyshire I.,Herbarium |
Tripp E.A.,University of Colorado at Boulder |
Onjalalaina G.E.,Kew Madagascar Conservation Center
Kew Bulletin | Year: 2017
The new species Ruellia domatiata I. Darbysh. & E. Tripp from northern Madagascar is described and illustrated and its affinities within the genus are discussed. This striking new species is currently assessed as Critically Endangered using the categories and criteria of the IUCN Red List. The presence of tuft-domatia on the undersurface of the leaves, a rare occurrence in the Acanthaceae family, is noted. © 2017, The Author(s).
Besnard G.,CNRS Biological Evolution and Diversity Laboratory |
Besnard G.,University Paul Sabatier |
Christin P.-A.,University of Sheffield |
Male P.-J.G.,CNRS Biological Evolution and Diversity Laboratory |
And 4 more authors.
Annals of Botany | Year: 2013
Background and AimsAn accurate characterization of biodiversity requires analyses of DNA sequences in addition to classical morphological descriptions. New methods based on high-throughput sequencing may allow investigation of specimens with a large set of genetic markers to infer their evolutionary history. In the grass family, the phylogenetic position of the monotypic genus Lecomtella, a rare bamboo-like endemic from Madagascar, has never been appropriately evaluated. Until now its taxonomic treatment has remained controversial, indicating the need for re-evaluation based on a combination of molecular and morphological data.MethodsThe phylogenetic position of Lecomtella in Poaceae was evaluated based on sequences from the nuclear and plastid genomes generated by next-generation sequencing (NGS). In addition, a detailed morphological description of L. madagascariensis was produced, and its distribution and habit were investigated in order to assess its conservation status.Key ResultsThe complete plastid sequence, a ribosomal DNA unit and fragments of low-copy nuclear genes (phyB and ppc) were obtained. All phylogenetic analyses place Lecomtella as an isolated member of the core panicoids, which last shared a common ancestor with other species >20 million years ago. Although Lecomtella exhibits morphological characters typical of Panicoideae, an unusual combination of traits supports its treatment as a separate group. Conclusions The study showed that NGS can be used to generate abundant phylogenetic information rapidly, opening new avenues for grass phylogenetics. These data clearly showed that Lecomtella forms an isolated lineage, which, in combination with its morphological peculiarities, justifies its treatment as a separate tribe: Lecomtelleae. New descriptions of the tribe, genus and species are presented with a typification, a distribution map and an IUCN conservation assessment. © 2013 The Author. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved.
Rakotoarinivo M.,Kew Madagascar Conservation Center |
Blach-Overgaard A.,University of Aarhus |
Baker W.J.,Royal Botanic Gardens |
Dransfield J.,Royal Botanic Gardens |
And 2 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2013
The distribution of rainforest in many regions across the Earth was strongly affected by Pleistocene ice ages. However, the extent to which these dynamics are still important for modern-day biodiversity patterns within tropical biodiversity hotspots has not been assessed. We employ a comprehensive dataset ofMadagascan palms (Arecaceae) and climate reconstructions from the last glacial maximum (LGM; 21 000 years ago) to assess the relative role of modern environment and LGMclimate in explaining geographical species richness patterns in this major tropical biodiversity hotspot. We found that palaeoclimate exerted a strong influence on palmspecies richness patterns,with richness peaking in areas with higher LGM precipitation relative to present-day even after controlling for modern environment, in particular in northeasternMadagascar, consistent with the persistence of tropical rainforest during the LGM primarily in this region.Our results provide evidence that diversity patterns in theWorld's most biodiverse regions may be shaped by long-term climate history as well as contemporary environment. & 2013 The Author(s) Published by the Royal Society. All rights reserved.
Contrasting patterns of genetic diversity between two endangered palms with overlapping distributions, Voanioala gerardii (Arecoideae) and Lemurophoenix halleuxii (Arecoideae), from North-east Madagascar
Shapcott A.,University of The Sunshine Coast |
Quinn J.,University of The Sunshine Coast |
Rakotoarinivo M.,Kew Madagascar Conservation Center |
Dransfield J.,Royal Botanic Gardens
Conservation Genetics | Year: 2012
Madagascar has a high diversity of endemic palm species and the Masoala Peninsula is a hotspot for their diversity. Several species are critically endangered and their populations known to be in decline due to a combination of land clearance, destructive harvesting for heart of palm and potentially unsustainable commercial seed collection. The critically endangered Voanioala gerardii and the endangered Lemurophoenix halleuxii are two palm species from monospecific genera endemic to Madagascar that overlap in their distribution within this region. This project undertook field surveys of all known populations of these two species to document their population sizes and locations. We modelled their area of potentially suitable habitat within the region and undertook genetic analysis to investigate genetic diversity and relatedness among populations of each species. The study found overlapping but contrasting patterns of potential habitat. It also found contrasting levels and patterns of genetic diversity between the two species that were not consistent with the modelled habitat distributions. We found that Voanioala gerardii populations are critically small but contain unexpectedly high levels of genetic diversity, which may indicate as yet undiscovered populations remaining. An active program to change methods of seed collection and to involve local villagers and land managers in the conservation of these species would be required to prevent their extinction. © 2012 Springer Science+Business Media B.V.
Taxonomic revision of Phyllanthus L. (Phyllanthaceae) in Madagascar and the Comoro Islands II: Subgenera Anisonemoides (Jean F. Brunel) Ralim. & Petra Hoffm., stat. nov. and Menarda (Müll. Arg.) Ralim. & Petra Hoffm., stat. nov.
Ralimanana H.,Kew Madagascar Conservation Center |
Adansonia | Year: 2014
In the second part of the taxonomic revision of Phyllanthus L. in Madagascar and the Comoro Islands the subgenera Anisonemoides (Jean F. Brunel) Ralim. & Petra Hoffm., stat. nov. and Menarda (Müll. Arg.) Ralim. & Petra Hoffm., stat. nov. are described. The subgenera are characterised by pinnatiform or bipinnatiform phyllanthoid branching, stamens are (2-4)5(-6) free or fused in Anesonemoides but 5, free stamens in Menarda; dehiscent fruits and tricolporate or trisyncolporate pollen with a macro-microreticulate exine, with muri bordering colpi, and one or two pores. they are endemic to Madagascar with most taxa being of limited geographic distribution. The subgenus Anisonemoides, stat. nov. comprises fifteen species and two species are belonging to Menarda, stat. nov. Four species from the Eastern floristic domain are newly described: Phyllanthus bemangidiensis Ralim., sp. nov., P. coodei Ralim. & Petra Hoffm., sp. nov., P. gordonii Ralim. & Petra Hoffm., sp. nov., and P. mantadiensis Ralim. & Petra Hoffm., sp. nov. Distribution maps and IUCN conservation assessment status are provided for each taxon. the circumscription of several species within Anisonemoides stat. nov. and Menarda stat. nov. has been revised. © Publications Scientifiques du Muséum national d'Histoire naturelle, Paris.
Onjalalaina G.E.,Kew Madagascar Conservation Center |
Kew Bulletin | Year: 2016
The new species Podorungia gesnerioides Onjalalaina & I. Darbysh. is described and illustrated and its affinities to the other species in the genus are discussed. It is the only species in Podorungia with an open dichasial inflorescence. This new species is assessed as globally "Endangered" following the Categories and Criteria of IUCN, because of threats to its lowland forest habitat. The generic delimitation of the Malagasy genera in the tribe Barlerieae is discussed and the similarities of the five endemic genera to the tropical African genus Crabbea are noted. A key to the genera of Barlerieae in Madagascar is provided, based on the key in Benoist’s Flore de Madagascar et des Comores account of the Acanthaceae. In addition, a brief review of current progress on the taxonomy of the Acanthaceae of Madagascar is provided. © 2016, The Board of Trustees of the Royal Botanic Gardens, Kew.
Rakotoarinivo M.,Kew Madagascar Conservation Center
Proceedings. Biological sciences / The Royal Society | Year: 2013
The distribution of rainforest in many regions across the Earth was strongly affected by Pleistocene ice ages. However, the extent to which these dynamics are still important for modern-day biodiversity patterns within tropical biodiversity hotspots has not been assessed. We employ a comprehensive dataset of Madagascan palms (Arecaceae) and climate reconstructions from the last glacial maximum (LGM; 21 000 years ago) to assess the relative role of modern environment and LGM climate in explaining geographical species richness patterns in this major tropical biodiversity hotspot. We found that palaeoclimate exerted a strong influence on palm species richness patterns, with richness peaking in areas with higher LGM precipitation relative to present-day even after controlling for modern environment, in particular in northeastern Madagascar, consistent with the persistence of tropical rainforest during the LGM primarily in this region. Our results provide evidence that diversity patterns in the World's most biodiverse regions may be shaped by long-term climate history as well as contemporary environment.
Vorontsova M.S.,Herbarium |
Ratovonirina G.,Kew Madagascar Conservation Center |
Randriamboavonjy T.,Kew Madagascar Conservation Center
Kew Bulletin | Year: 2013
Summary: A revision of Andropogon and Diectomis in Madagascar is presented with nine species and two subspecies (including eight native and seven endemic species) in Andropogon, and one species in Diectomis. Andropogon itremoensis from the Itremo Massif is described and illustrated. The Itremo Massif is briefly described and the conservation implications of the new species are discussed. Full typification is presented for species endemic to Madagascar and lectotypes are selected for five names. Distribution maps are presented. © 2013 The Board of Trustees of the Royal Botanic Gardens, Kew.
Rakotoarinivo M.,Kew Madagascar Conservation Center |
Dransfield J.,Royal Botanic Gardens |
Bachman S.P.,Royal Botanic Gardens |
Moat J.,Royal Botanic Gardens |
Baker W.J.,Royal Botanic Gardens
PLoS ONE | Year: 2014
The establishment of baseline IUCN Red List assessments for plants is a crucial step in conservation planning. Nowhere is this more important than in biodiversity hotspots that are subject to significant anthropogenic pressures, such as Madagascar. Here, all Madagascar palm species are assessed using the IUCN Red List categories and criteria, version 3.1. Our results indicate that 83% of the 192 endemic species are threatened, nearly four times the proportion estimated for plants globally and exceeding estimates for all other comprehensively evaluated plant groups in Madagascar. Compared with a previous assessment in 1995, the number of Endangered and Critically Endangered species has substantially increased, due to the discovery of 28 new species since 1995, most of which are highly threatened. The conservation status of most species included in both the 1995 and the current assessments has not changed. Where change occurred, more species have moved to lower threat categories than to higher categories, because of improved knowledge of species and their distributions, rather than a decrease in extinction risk. However, some cases of genuine deterioration in conservation status were also identified. Palms in Madagascar are primarily threatened by habitat loss due to agriculture and biological resource use through direct exploitation or collateral damage. The recent extension of Madagascar's protected area network is highly beneficial for palms, substantially increasing the number of threatened species populations included within reserves. Notably, three of the eight most important protected areas for palms are newly designated. However, 28 threatened and data deficient species are not protected by the expanded network, including some Critically Endangered species. Moreover, many species occurring in protected areas are still threatened, indicating that threatening processes persist even in reserves. Definitive implementation of the new protected areas combined with local community engagement are essential for the survival of Madagascar's palms. © 2014 Rakotoarinivo et al.
PubMed | Anglia, University of Antananarivo, University of Nottingham, National Museums of Kenya and 6 more.
Type: Journal Article | Journal: Proceedings. Biological sciences | Year: 2016
Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics.