Flore et feux dans une mosaïque de forêts et de savanes anciennes d'Afrique centrale : Check‐list du Parc National des Plateaux Batéké (Gabon)

RESUME Contexte et buts – Les savanes anciennes d'Afrique sont influencées par les feux, possèdent des suffrutices géoxyliques et endémiques et elles sont encore peu étudiées. Le présent article est une étude du Parc National des Plateaux Batéké (PNPB) au Gabon et de l'incidence des feux sur sa flore en vue de comprendre s'il constitue une savane ancienne Il présente 1) une check-liste des plantes vasculaires, y compris des espèces endémiques et des suffrutices géoxyliques et 2) une analyse de l'incidence des feux sur la flore de la savane herbacée suivie de recommandations relatives à la lutte contre les feux en vue de promouvoir la diversité végétale. Matériau et méthodes – 1,914 collections botaniques constituées de 2001 à 2019 par les auteurs (de la présente étude) et d'autres étaient extraites des bases de données des MO et des NHN en 2021 pour créer la check-list. L'incidence des feux a été étudiée travers un inventaire sur trois saisons, des herbacées et des suffrutices géoxyliques effectué sur des parcelles dans cinq zones d'étude situées à 600 m d'altitude et brulée tous les ans en saison sèche. Une analyse de variance à deux facteurs a été effectuée à travers deux traitements de brûlages et des traitements sur trois saisons. Principaux résultats – La zone possède une flore vasculaire de 616 taxons. Sept espèces sont endémiques dans la mosaïque de forêts et de savanes des Plateaux Batéké. 17 espèces sont des suffrutices géoxyliques dépendants du feu, ce qui atteste des origines anciennes de ces savanes. Les feux favorisent le développement des espèces dépendantes du feu. Conclusion – L'objectif du PNPB est de créer un plan de gestion des feux culturellement adapté. La combinaison des feux coutumiers et des espèces adaptées au feu dans la savane crée une mosaïque de forêts et de savanes unique en Afrique centrale, qui mérite d'être protégée en même temps qu'est reconnu le rôle que jouent les populations Batéké-Alima dans le façonnage du paysage de la zone et sa gouvernance

Two new records of palm species for Gabon: Sclerosperma profizianum Valk. & Sunder. and Eremospatha quiquecostulata Becc.

Gabon is an important center of biodiversity in Central Africa. The country contains to date 27 species of palms. However, palms are generally poorly collected as these massive plants are hard to press and curate. Thus, our understanding remains incomplete, especially in Central Africa. We report three new records of two palm species for Gabon: Sclerosperma profizianum Valk. & Sunder. and Eremospatha quiquecostulata Becc.. The former species was collected in southeast Gabon, near Ndindi, while the later was collected in the Massif du Chaillu and Monts de Cristal National Park (Crystal Mountains National Park). The total number of palm species for Gabon is now 29, making it an important centre of palm diversity in Central Africa

Two new species of Raphia (Palmae/Arecaceae) from Cameroon and Gabon

Raphia (Arecaceae, Calamoideae) is the most diverse genus of African palms with around 20 species. Two new species from Cameroon and Gabon, Raphia gabonica Mogue, Sonké & Couvreur, sp. nov. and Raphia zamiana Mogue, Sonké & Couvreur, sp. nov. are described and illustrated. Their affinities are discussed and the conservation status of each species is assessed. For both species, distribution maps are provided. Raphia gabonica is restricted to two small populations from central Gabon, where it occurs on hillsides on tierra firme soil, and close to small streams. Its preliminary IUCN status is Endangered, being amongst the five most threatened palm species in Africa. Raphia gabonica potentially belongs to the moniliform section. Raphia zamiana is largely distributed from south Cameroon to south Gabon and is very common. It is also a multi-used palm, from which wine, grubs and construction material are extracted and sold. It generally occurs in large stands in a wide range of ecosystems such as swamps, coastal forests on partially inundated sandy soils and inundated savannahs. Its large stature, hard to access habitat (swamps) and abundant presence might have discouraged botanists to collect it until now. Raphia zamiana belongs to the taxonomically complex raphiate section

New species of Uvariopsis (Annonaceae) and Laccosperma (Arecaceae/Palmae) from Monts de Cristal, Gabon

International audienceMonts de Cristal National Park in northwest Gabon is one of the most species rich places in Central Africa. Here, we describe two new species, one in Annonaceae and one in palms. Uvariopsis citrata Couvreur & Niangadouma, sp. nov. is unique in the genus by emitting a strong lemon scent from the crushed leaves and young branches. Laccosperma cristalensis Couvreur & Niangadouma, sp. nov. is a rattan that lacks acanthophylls on the cirrus and has few pinnae. Complete descriptions, photographic illustrations, ecological information and preliminary IUCN conservation status are provided. For both species a data deficient (DD) status is proposed. These new species underline once again that the Monts de Cristal National Park is yet incompletely known botanically

Flora and fire in an old-growth Central African forest-savanna mosaic: a checklist of the Parc National des Plateaux Batéké (Gabon)

Background and aims – Old-growth savannas in Africa are impacted by fire, have endemic and geoxylic suffrutices, and are understudied. This paper explores the Parc National des Plateaux Batéké (PNPB) in Gabon and the impact of fire on its flora to understand if it is an old-growth savanna. It presents 1) a vascular plant checklist, including endemic species and geoxylic suffrutices and 2) an analysis of the impact of fire on the savanna herbaceous flora, followed by recommendations for fire management to promote plant diversity. Material and methods – 1,914 botanical collections from 2001–2019 collected by the authors and others were extracted from two herbaria databases in 2021 to create the checklist. The impact of fire was explored through a three season plot-based inventory of plant species (notably forbs and geoxylic suffrutices) in five annually, dry-season burned study areas located at 600 m in elevation. A two-factor ANOVA was conducted across two burn treatments and three season treatments. Key results – The area has a vascular flora of 615 taxa. Seven species are endemic to the Plateaux Batéké forest-savanna mosaic. Seventeen species are fire-dependent geoxylic suffrutices, attesting to the ancient origins of these savannas. Burning promotes fire-dependent species. Conclusion – The PNPB aims to create a culturally-adapted fire management plan. The combination of customary fire and fire-adapted species in the savanna creates a unique ancient forest-savanna mosaic in Central Africa that merits protection while recognising the role that the Batéké-Alima people have in shaping and governing this landscape

Flora and fire in an old-growth Central African forest-savanna mosaic: a checklist of the Parc National des Plateaux Batéké (Gabon)

Background and aims – Old-growth savannas in Africa are impacted by fire, have endemic and geoxylic suffrutices, and are understudied. This paper explores the Parc National des Plateaux Batéké (PNPB) in Gabon and the impact of fire on its flora to understand if it is an old-growth savanna. It presents 1) a vascular plant checklist, including endemic species and geoxylic suffrutices and 2) an analysis of the impact of fire on the savanna herbaceous flora, followed by recommendations for fire management to promote plant diversity. Material and methods – 1,914 botanical collections from 2001–2019 collected by the authors and others were extracted from two herbaria databases in 2021 to create the checklist. The impact of fire was explored through a three season plot-based inventory of plant species (notably forbs and geoxylic suffrutices) in five annually, dry-season burned study areas located at 600 m in elevation. A two-factor ANOVA was conducted across two burn treatments and three season treatments. Key results – The area has a vascular flora of 615 taxa. Seven species are endemic to the Plateaux Batéké forest-savanna mosaic. Seventeen species are fire-dependent geoxylic suffrutices, attesting to the ancient origins of these savannas. Burning promotes fire-dependent species. Conclusion – The PNPB aims to create a culturally-adapted fire management plan. The combination of customary fire and fire-adapted species in the savanna creates a unique ancient forest-savanna mosaic in Central Africa that merits protection while recognising the role that the Batéké-Alima people have in shaping and governing this landscape

Sirdavidia, an extraordinary new genus of Annonaceae from Gabon

International audienceA distinctive new monotypic genus from Gabon is described in the tropical plant family Annonaceae: Sirdavidia, in honor to Sir David Attenborough. Molecular phylogenetic analyses confirm that Sirdavidia, which is very distinct from a morphological standpoint, is not nested in any existing genus of Annonaceae and belongs to tribe Piptostigmateae (subfamily Malmeoideae), which now contains a total of six genera. The genus is characterized by long acuminate leaves, fully reflexed red petals, 16-19 bright yellow, loosely arranged stamens forming a cone, and a single carpel topped by a conspicuous stigma. With just three known collections, a preliminary IUCN conservation status assessment is provided as "endangered" as well as a distribution map. The discovery of Sirdavidia is remarkable at several levels. First, it was collected near the road in one of the botanically best-known regions of Gabon: Monts de Cristal National Park. Second, its sister group is the genus Mwasumbia, also monotypic, endemic to a small area in a forest in Tanzania, some 3000 km away. Finally, the floral morphology is highly suggestive of a buzz pollination syndrome. If confirmed, this would be the first documentation of such a pollination syndrome in Magnoliidae and early-diverging angiosperms in general.Un nouveau genre monotypique du Gabon est décrit dans la famille tropicale des Annonaceae: Sirdavidia, en honneur à Sir David Attenborough. Des analyses phylogénétiques confirment que Sirdavidia, caractérisé par une morphologie unique, n’appartient à aucun genre connu d’Annonaceae et se place au sein de la tribu des Piptostigmateae (dans la sous-famille des Malmeoideae), laquelle compte désormais un total de six genres. Le genre est caractérisé par des feuilles avec un long acumen, des pétales rouges réfléchis, 16–19 étamines jaunes qui forment un cône lâche et un carpelle surmonté d’un stigmate bien visible. Avec seulement trois récoltes connues, un statut de conservation préliminaire de “endangered” est proposé sur la base des critères de l’UICN. Une carte de distribution est également fournie. La découverte de Sirdavidia est remarquable pour plusieurs raisons. Tout d’abord le nouveau genre a été collecté près de la route dans l’une des régions les plus connues botaniquement du Gabon: le Parc National des Monts de Cristal. Ensuite, son groupe-frère est le genre, Mwasumbia, également monotypique, endémique d’une petite région en Tanzanie à plus de 3000 km. Enfin, les caractères floraux suggèrent un syndrome de pollinisation appélé « buzz pollination». Si cela se confirme, ce sera la première documentation de ce type de syndrome pour les Magnoliidae et les Angiospermes basales en général