A sharp floristic discontinuity revealed by the biogeographic regionalization of African savannas

Fayolle Adeline, Swaine Mike D., Aleman Julie, Azihou Akomian Fortuné, Bauman David, te Beest Mariska, Chidumayo Emmanuel N., Cromsigt Joris P.G.M., Dessard Hélène, Finckh Manfred, Gonçalves Francisco Maiato P., Gillet Jean-François, Gorel Anaïs-Pasiphaé, Hick Aurélie, Holdo Ricardo, Kirunda Ben, Mahy Gregory, McNicol Iain, Ryan Casey M., Revermann Rasmus, Plumptre Andrew J., Pritchard Rose, Nieto-Quintano Paula, Schmitt Christine B., Seghieri Josiane, Swemmer Anthony, Talila Habte, Woollen Emily. 2019. A sharp floristic discontinuity revealed by the biogeographic regionalization of African savannas. Journal of Biogeography, 46 (2) : 454-465.

Url - jeu de données - Entrepôt autre : https://orbi.uliege.be/handle/2268/227793

Quartile : Q1, Sujet : ECOLOGY / Quartile : Q1, Sujet : GEOGRAPHY, PHYSICAL

Liste HCERES des revues (en SHS) : oui

Thème(s) HCERES des revues (en SHS) : Géographie-Aménagement-Urbanisme-Architecture

Résumé : Aim: In tropical Africa, savannas cover huge areas, have high plant species richness and are considered as a major natural resource for most countries. There is, however, little information available on their floristics and biogeography at the continental scale, despite the importance of such information for our understanding of the drivers of species diversity at various scales and for effective conservation and management. Here, we collated and analysed floristic data from across the continent in order to propose a biogeographical regionalization for African savannas. Location: We collated floristic information (specifically woody species lists) for 298 samples of savanna vegetation across Africa, extending from 18° N to 33° S and from 17° W to 48° E. Taxa: We focused on native woody species. Methods: We used ordination and clustering to identify the floristic discontinuities and gradual transitions across African savannas. Floristic relationships, specificity and turnover, within and between floristic clusters, were analysed using a (dis‐)similarity‐based approach. Results: We identified eight floristic clusters across African savannas which in turn were grouped into two larger macro‐units. Ordinations at species and genus levels showed a clear differentiation in woody species composition between the North/West macro‐unit and the South/East macro‐unit. This floristic discontinuity matches to the High (i.e. N&W) and Low (S&E) division of Africa previously proposed by White (1983) and which tracks climatic and topographical variation. In the N&W savannas, the floristic gradient determined by rainfall was partitioned into the Sudanian (drier) and Guinean (wetter) clusters. Within the highly heterogeneous S&E savannas and woodlands, six clusters were identified: Ugandan, Ethiopian, Mozambican, Zambezian, Namibian and South African. Main conclusions : The proposed pan‐African classification of savannas and woodlands might assist the development of coordinated management and conservation policies.

Mots-clés Agrovoc : savane, flore, biodiversité, biogéographie, précipitation, température, composition botanique, plante indicatrice

Mots-clés géographiques Agrovoc : Afrique tropicale, Afrique

Mots-clés libres : Biogeographical regions, Clustering, Distance decay in similarity, Floristic clusters, Rainfall and altitude, Indicator species, Savannas, Correspondence analysis, Temperature gradients

Classification Agris : F70 - Taxonomie végétale et phytogéographie
P40 - Météorologie et climatologie
P01 - Conservation de la nature et ressources foncières

Champ stratégique Cirad : CTS 1 (2019-) - Biodiversité

Auteurs et affiliations

• Fayolle Adeline, Université de Liège (BEL)
• Swaine Mike D., Aberdeen University African Studies Group (GBR) - auteur correspondant
• Aleman Julie, Université de Montréal (CAN)
• Azihou Akomian Fortuné, UAC (BEN)
• Bauman David, ULB (BEL)
• te Beest Mariska, Utrecht University (NLD)
• Chidumayo Emmanuel N., Makeni Savanna Research Project (ZMB)
• Cromsigt Joris P.G.M., Swedish University of Agricultural Sciences (SWE)
• Dessard Hélène, CIRAD-ES-UPR Forêts et sociétés (FRA)
• Finckh Manfred, Universität Hamburg (DEU)
• Gonçalves Francisco Maiato P., ISCED (AGO)
• Gillet Jean-François, Université de Liège (BEL)
• Gorel Anaïs-Pasiphaé, AgroParisTech (FRA)
• Hick Aurélie, Université de Liège (BEL)
• Holdo Ricardo, University of Georgia (GRC)
• Kirunda Ben, Wildlife Conservation Society (UGA)
• Mahy Gregory, Université de Liège (BEL)
• McNicol Iain, University of Edinburgh (GBR)
• Ryan Casey M., University of Edinburgh (GBR)
• Revermann Rasmus, Wildlife Conservation Society (UGA)
• Plumptre Andrew J., Wildlife Conservation Society (USA)
• Pritchard Rose, University of Edinburgh (GBR)
• Nieto-Quintano Paula, University of Edinburgh (GBR)
• Schmitt Christine B., Universität Freiburg (DEU)
• Seghieri Josiane, IRD (FRA)
• Swemmer Anthony, SAEON (ZAF)
• Talila Habte, Madda Walabu University (ETH)
• Woollen Emily, University of Edinburgh (GBR)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/590462/)

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