Biogeographic factors and their influence on diversity patterns of clade A of Tigridieae in South America

Resumen

The geographical distribution of monocotyledonous geophytes is linked to thermally variable climates. This study identified spatial patterns of species diversity in clade A of Tigridieae, a strictly geophytic lineage with varying presence of elaiophores among species. We assessed the influence of current and past climatic variables on distribution patterns and the potential identification of cohesive biogeographic units. We compiled distribution data for 73 taxa of clade A in South America, estimating the geographic distribution of each taxon using climatic niche modeling and creating maps of diversity metrics. Correlative models with climatic variables were used to assess their effect on each metric. Infomap-Bioregions and NDM-VNDM algorithms helped identify biogeographic units. Species of clade A followed an atypical latitudinal gradient, with the greatest turnover observed along the Tropic of Capricorn. Higher species richness, particularly for species with elaiophores, was strongly associated with subtropical subhumid grasslands. The highest species diversity (30 species) and endemism (11 species) were found in the area spanning southern Brazil, northern Uruguay, and northeastern Argentina. Temperature variables strongly influenced clade distribution, and cohesive biogeographic units were identified across its range.

 Citación: Báez-Lizarazo, M.R., Reginato, M., Souza-Chies, T.T., Chauveau, O. & Eggers, L. 2025. Biogeographic factors and their influence on diversity patterns of clade A of Tigridieae in South America. Revista Jard. Bot. Nac. Univ. Habana 46(Número especial 1): 63.  

Trabajo presentado en el XIII Congreso Latinoamericano de Botánica. Sesión Sistemática, Filogenia, Biogeografía y Evolución.