The Neogene rise of the tropical Andes facilitated diversification of wax palms (Ceroxylon: Arecaceae) through geographical colonization and climatic niche separation

• Published in: Botanical journal of the Linnean Society Vol. 182; no. 2; pp. 303 - 317
• Main Authors: Sanín, María J., Kissling, W. Daniel, Bacon, Christine D., Borchsenius, Finn, Galeano, Gloria, Svenning, Jens-Christian, Olivera, José, Ramírez, Rina, Trénel, Philip, Pintaud, Jean-Christophe
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.10.2016; Linnean Society of London
• Subjects: Andes region; Arecaceae; Biodiversity; Biodiversity hot spots; Biogeography; Biological Systematics; Biologisk systematik; botanical composition; Botanik; Botany; Ceroxylon; Climate change; climatic factors; cold adaptation; Colonization; Ecology; Ekologi; Life Sciences; Low temperature; Miocene; Neogene; Neotropics; niche shift; Niches; Orogeny; phylogenetic niche conservatism; phylogeny; Pliocene; range expansion; Speciation; Temperature gradients; temperature profiles; Vegetal Biology; Andes Mountains; Andes region; range expansion; Miocene; Neotropics; niche shift; phylogenetic niche conservatism; cold adaptation; Bolivie; Andes; Equateur; Range expansion; Pérou; Venezuela; Niche shift; Phylogenetic niche conservatism; Cold adaptation; Zones tropicales; Colombie
• ISSN: 0024-4074; 1095-8339; 1095-8339
• DOI: 10.1111/boj.12419

Abstract The tropical Andes are a biodiversity hotspot, partly due to their rich and complex floristic composition. A fundamental question regarding this outstanding biodiversity is what role the Andean orogeny has played in species diversification. Ceroxylon is a genus of endemic Andean palms that stands out in the palm family (Arecaceae) due to its adaptation to cold, mountainous environments. Here, we reconstruct the biogeography and climatic preference of this lineage to test the hypothesis that Andean uplift allowed diversification by providing suitable habitats along climatic and elevational gradients. Ancestral areas were reconstructed under a model allowing for founder-event speciation and climatic niches were inferred from climatic variables at present-day occurrences of all species. Niche evolution in a phylogenetic framework was evaluated by testing differences between the climatic niches of clades. Our analyses identified four main clades, with a general pattern of diversification through geographical colonization from south to north after the Pliocene uplift of the northern Andes. Adaptation to low temperatures was conserved at the generic level, with climatic niche differentiation among clades along elevational temperature gradients. We conclude that the Neogene Andean uplift has facilitated the diversification of this iconic plant group via opportunities for geographical migration and separation within its climatic niche.