Suchergebnisse

This book presents the results of the IUCN Red List evaluation of all 347 tree taxa with a distribution confined to, or almost confined to, Central Africa (Democratic Republic of the Congo – Rwanda – Burundi). As such, it is part of a global endeavour involving over 60 organisations coordinated by Botanic Gardens Conservation International (BGCI), and culminating in the Global Tree Assessment. Endangered animals generally attract lots of attention, but trees are far more vulnerable. There are nearly 60,000 tree species recognised worldwide, and we now know that 30% (17,500 species) are threatened with extinction. This is higher than the number of all threatened mammals, birds, amphibians, and reptiles combined! The data on the 347 Central African trees presented here shows that 221 (64%) of them are at risk of extinction. Of these, 34 (10%) are critically endangered, of which 25 may already be extinct. Agriculture, livestock farming, and logging are the main global threats. Climate change impacts are emerging, and in Central Africa, charcoal production and mining also provide major pressures. Further, this volume provides a useful overview of all Protected Areas (PAs) in the region, with the (sub)endemic tree taxa they contain. Management plans can now be adjusted and improved taking this information into account. Several other recommendations are listed. Focussed action is needed to ensure the survival of threatened tree species, and all organisms (including humans) that depend on them.

International audience ; The phylogenetic position of Rangaeris (Schltr.) Summerh. has been one of the most problematic issues of angraecoid orchid taxonomy. A recently published phylogenetic tree with nearly comprehensive taxon sampling of African angraecoid orchids suggested that this genus was polyphyletic, as its species appear nested within different subclades of the Cyrtorchis–Tridactyle clade. However, the lack of DNA data for the generic type, R. muscicola (Rchb. f.) Summerh., and for the little-known species R. longicaudata (Rolfe) Summerh. and R. trilobata Summerh., has precluded an integrative reappraisal of the delimitation of this genus. Here we present the results of a new phylogenetic analysis of one nuclear (ITS) and five plastid markers (matK, rps16, trnC-petN intergenic spacer, trnL-trnF intergenic spacer, ycf1) for all six species of Rangaeris, including those recently transferred to Podangis Schltr. and Ypsilopus Summerh., together with a representative sampling of 14 other species of the genera Cyrtorchis Schltr., Listrostachys Rchb. f., Plectrelminthus Raf., Summerhayesia P. J. Cribb, Tridactyle Schltr., and Ypsilopus. Based on molecular and morphological evidence, R. muscicola is transferred to Podangis, where Rangaeris is reduced to the rank of section. In addition, R. longicaudata and R. trilobata are each moved to new monotypic genera, Planetangis Stévart & Farminhão and Aziza Farminhão & D'haijère, respectively. An identification key for all genera of the Cyrtorchis–Tridactyle clade is presented, together with one for the three species of recircumscribed Podangis. Finally, taxonomic accounts of the new genera are presented, including amended descriptions, illustrations, distribution maps, and preliminary conservation status assessments of their species.

International audience ; The phylogenetic position of Rangaeris (Schltr.) Summerh. has been one of the most problematic issues of angraecoid orchid taxonomy. A recently published phylogenetic tree with nearly comprehensive taxon sampling of African angraecoid orchids suggested that this genus was polyphyletic, as its species appear nested within different subclades of the Cyrtorchis–Tridactyle clade. However, the lack of DNA data for the generic type, R. muscicola (Rchb. f.) Summerh., and for the little-known species R. longicaudata (Rolfe) Summerh. and R. trilobata Summerh., has precluded an integrative reappraisal of the delimitation of this genus. Here we present the results of a new phylogenetic analysis of one nuclear (ITS) and five plastid markers (matK, rps16, trnC-petN intergenic spacer, trnL-trnF intergenic spacer, ycf1) for all six species of Rangaeris, including those recently transferred to Podangis Schltr. and Ypsilopus Summerh., together with a representative sampling of 14 other species of the genera Cyrtorchis Schltr., Listrostachys Rchb. f., Plectrelminthus Raf., Summerhayesia P. J. Cribb, Tridactyle Schltr., and Ypsilopus. Based on molecular and morphological evidence, R. muscicola is transferred to Podangis, where Rangaeris is reduced to the rank of section. In addition, R. longicaudata and R. trilobata are each moved to new monotypic genera, Planetangis Stévart & Farminhão and Aziza Farminhão & D'haijère, respectively. An identification key for all genera of the Cyrtorchis–Tridactyle clade is presented, together with one for the three species of recircumscribed Podangis. Finally, taxonomic accounts of the new genera are presented, including amended descriptions, illustrations, distribution maps, and preliminary conservation status assessments of their species.

International audience ; The phylogenetic position of Rangaeris (Schltr.) Summerh. has been one of the most problematic issues of angraecoid orchid taxonomy. A recently published phylogenetic tree with nearly comprehensive taxon sampling of African angraecoid orchids suggested that this genus was polyphyletic, as its species appear nested within different subclades of the Cyrtorchis–Tridactyle clade. However, the lack of DNA data for the generic type, R. muscicola (Rchb. f.) Summerh., and for the little-known species R. longicaudata (Rolfe) Summerh. and R. trilobata Summerh., has precluded an integrative reappraisal of the delimitation of this genus. Here we present the results of a new phylogenetic analysis of one nuclear (ITS) and five plastid markers (matK, rps16, trnC-petN intergenic spacer, trnL-trnF intergenic spacer, ycf1) for all six species of Rangaeris, including those recently transferred to Podangis Schltr. and Ypsilopus Summerh., together with a representative sampling of 14 other species of the genera Cyrtorchis Schltr., Listrostachys Rchb. f., Plectrelminthus Raf., Summerhayesia P. J. Cribb, Tridactyle Schltr., and Ypsilopus. Based on molecular and morphological evidence, R. muscicola is transferred to Podangis, where Rangaeris is reduced to the rank of section. In addition, R. longicaudata and R. trilobata are each moved to new monotypic genera, Planetangis Stévart & Farminhão and Aziza Farminhão & D'haijère, respectively. An identification key for all genera of the Cyrtorchis–Tridactyle clade is presented, together with one for the three species of recircumscribed Podangis. Finally, taxonomic accounts of the new genera are presented, including amended descriptions, illustrations, distribution maps, and preliminary conservation status assessments of their species.

International audience ; Preserving tropical biodiversity is an urgent challenge when faced with the growing needs of countries. Despite their crucial importance for terrestrial ecosystems, most tropical plant species lack extinction risk assessments, limiting our ability to identify conservation priorities. Using a novel approach aligned with IUCN Red List criteria, we conducted a continental-scale preliminary conservation assessment of 22,036 vascular plant species in tropical Africa. Our results underline the high level of extinction risk of the tropical African flora. Thirty-three percent of the species are potentially threatened with extinction, and another third of species are likely rare, potentially becoming threatened in the near future. Four regions are highlighted with a high proportion (>40%) of potentially threatened species: Ethiopia, West Africa, central Tanzania, and southern Democratic Republic of the Congo. Our approach represents a first step toward data-driven conservation assessments applicable at continental scales providing crucial information for sustainable economic development prioritization.

International audience ; Preserving tropical biodiversity is an urgent challenge when faced with the growing needs of countries. Despite their crucial importance for terrestrial ecosystems, most tropical plant species lack extinction risk assessments, limiting our ability to identify conservation priorities. Using a novel approach aligned with IUCN Red List criteria, we conducted a continental-scale preliminary conservation assessment of 22,036 vascular plant species in tropical Africa. Our results underline the high level of extinction risk of the tropical African flora. Thirty-three percent of the species are potentially threatened with extinction, and another third of species are likely rare, potentially becoming threatened in the near future. Four regions are highlighted with a high proportion (>40%) of potentially threatened species: Ethiopia, West Africa, central Tanzania, and southern Democratic Republic of the Congo. Our approach represents a first step toward data-driven conservation assessments applicable at continental scales providing crucial information for sustainable economic development prioritization.

International audience ; Preserving tropical biodiversity is an urgent challenge when faced with the growing needs of countries. Despite their crucial importance for terrestrial ecosystems, most tropical plant species lack extinction risk assessments, limiting our ability to identify conservation priorities. Using a novel approach aligned with IUCN Red List criteria, we conducted a continental-scale preliminary conservation assessment of 22,036 vascular plant species in tropical Africa. Our results underline the high level of extinction risk of the tropical African flora. Thirty-three percent of the species are potentially threatened with extinction, and another third of species are likely rare, potentially becoming threatened in the near future. Four regions are highlighted with a high proportion (>40%) of potentially threatened species: Ethiopia, West Africa, central Tanzania, and southern Democratic Republic of the Congo. Our approach represents a first step toward data-driven conservation assessments applicable at continental scales providing crucial information for sustainable economic development prioritization.

Preserving tropical biodiversity is an urgent challenge when faced with the growing needs of countries. Despite their crucial importance for terrestrial ecosystems, most tropical plant species lack extinction risk assessments, limiting our ability to identify conservation priorities. Using a novel approach aligned with IUCN Red List criteria, we conducted a continental-scale preliminary conservation assessment of 22,036 vascular plant species in tropical Africa. Our results underline the high level of extinction risk of the tropical African flora. Thirty-three percent of the species are potentially threatened with extinction, and another third of species are likely rare, potentially becoming threatened in the near future. Four regions are highlighted with a high proportion (>40%) of potentially threatened species: Ethiopia, West Africa, central Tanzania, and southern Democratic Republic of the Congo. Our approach represents a first step toward data-driven conservation assessments applicable at continental scales providing crucial information for sustainable economic development prioritization. ; SCOPUS: ar.j ; info:eu-repo/semantics/published