Floristic evidence for alternative biome states in tropical Africa

Aleman Julie, Fayolle Adeline, Favier Charly, Staver A.C., Dexter Kyle G., Ryan Casey M., Azihou Akomian Fortuné, Bauman David, te Beest Mariska, Chidumayo Emmanuel N., Comiskey James A., Cromsigt Joris P.G.M., Dessard Hélène, Doucet Jean-Louis, Finckh Manfred, Gillet Jean-François, Gourlet-Fleury Sylvie, Hempson G.P., Holdo Ricardo, Kirunda Ben, Kouame F.N., Mahy Gregory, Gonçalves Francisco Maiato P., McNicol Iain, Quintano P. Nieto, Plumptre Andrew J., Pritchard Rose, Revermann R., Schmitt Christine B., Swemmer Anthony, Talila Habte, Woollen Emily, Swaine Mike D.. 2020. Floristic evidence for alternative biome states in tropical Africa. Proceedings of the National Academy of Sciences of the United States of America, 117 (45) : 28183-28190.

Url - autres données associées : https://CRAN.R-project.org/package=dismo / Url - autres données associées : https://CRAN.R-project.org/package=raster / Url - autres données associées : https://CRAN.R-project.org/package=labdsv

Quartile : Outlier, Sujet : MULTIDISCIPLINARY SCIENCES

Liste HCERES des revues (en SHS) : oui

Thème(s) HCERES des revues (en SHS) : Economie-gestion; Psychologie-éthologie-ergonomie

Résumé : The idea that tropical forest and savanna are alternative states is crucial to how we manage these biomes and predict their future under global change. Large-scale empirical evidence for alternative stable states is limited, however, and comes mostly from the multimodal distribution of structural aspects of vegetation. These approaches have been criticized, as structure alone cannot separate out wetter savannas from drier forests for example, and there are also technical challenges to mapping vegetation structure in unbiased ways. Here, we develop an alternative approach to delimit the climatic envelope of the two biomes in Africa using tree species lists gathered for a large number of forest and savanna sites distributed across the continent. Our analyses confirm extensive climatic overlap of forest and savanna, supporting the alternative stable states hypothesis for Africa, and this result is corroborated by paleoecological evidence. Further, we find the two biomes to have highly divergent tree species compositions and to represent alternative compositional states. This allowed us to classify tree species as forest vs. savanna specialists, with some generalist species that span both biomes. In conjunction with georeferenced herbarium records, we mapped the forest and savanna distributions across Africa and quantified their environmental limits, which are primarily related to precipitation and seasonality, with a secondary contribution of fire. These results are important for the ongoing efforts to restore African ecosystems, which depend on accurate biome maps to set appropriate targets for the restored states but also provide empirical evidence for broad-scale bistability.

Mots-clés Agrovoc : succession végétale, communauté végétale, forêt tropicale, savane, cartographie des fonctions de la forêt, indice de végétation, écosystème forestier, données spatiales

Mots-clés géographiques Agrovoc : Afrique tropicale

Mots-clés complémentaires : biome

Mots-clés libres : Alternative stable states, Tropical biomes, Tree species composition, Precipitation and seasonality, Fire

Classification Agris : F40 - Écologie végétale
F70 - Taxonomie végétale et phytogéographie

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

Auteurs et affiliations

• Aleman Julie, Université de Montréal (CAN)
• Fayolle Adeline, AgroParisTech (BEL) - auteur correspondant
• Favier Charly, CNRS (FRA)
• Staver A.C., Yale University (USA)
• Dexter Kyle G., University of Edinburgh (GBR)
• Ryan Casey M., University of Edinburgh (GBR)
• Azihou Akomian Fortuné, UAC (BEN)
• Bauman David, ULB (BEL)
• te Beest Mariska, Utrecht University (NLD)
• Chidumayo Emmanuel N., Makeni Savanna Research Project (ZMB)
• Comiskey James A., National Park Service (USA)
• Cromsigt Joris P.G.M., Swedish University of Agricultural Sciences (SWE)
• Dessard Hélène, CIRAD-ES-UPR Forêts et sociétés (FRA)
• Doucet Jean-Louis, AgroParisTech (BEL)
• Finckh Manfred, Universität Hamburg (DEU)
• Gillet Jean-François, Université de Liège (BEL)
• Gourlet-Fleury Sylvie, CIRAD-ES-UPR Forêts et sociétés (FRA) ORCID: 0000-0002-1136-4307
• Hempson G.P., University of the Witwatersrand (ZAF)
• Holdo Ricardo, University of Georgia (GRC)
• Kirunda Ben, Wildlife Conservation Society (UGA)
• Kouame F.N., UNA [Université Nangui Abrogoua] (CIV)
• Mahy Gregory, Université de Liège (BEL)
• Gonçalves Francisco Maiato P., ISCED (AGO)
• McNicol Iain, University of Edinburgh (GBR)
• Quintano P. Nieto, University of Edinburgh (GBR)
• Plumptre Andrew J., Wildlife Conservation Society (USA)
• Pritchard Rose, University of Edinburgh (GBR)
• Revermann R., Universität Hamburg (DEU)
• Schmitt Christine B., Universität Freiburg (DEU)
• Swemmer Anthony, SAEON (ZAF)
• Talila Habte, Madda Walabu University (ETH)
• Woollen Emily, University of Edinburgh (GBR)
• Swaine Mike D., Aberdeen University African Studies Group (GBR)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/599761/)

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