Abstract Detail

Biogeography

Rosas, Marcelo [1], Segovia, Ricardo A. [2], Guerrero, Pablo C. [2].

Biogeographic patterns in an amphitropical long-dispersal clade of goldenbusches (Asteraceae): comparing arid climate-type analogs in North and South America.

Long-distance dispersal is an increasingly well-known process, and amphitropical dispersals events between hemispheres contribute to North and South American floras. In this study, we analyzed richness and distribution patterns of a 60 species genus Haplopappus (Asteraceae, Astereae) in South America (SA) and its closest relatives in North America (NA), all inhabiting the arid western areas of both subcontinents. Our goals were: i) to identify the sister lineages of Haplopappus, ii) to compare the climatic niches of NA and SA species, iii) to investigate geographic patterns and to explore temperature and precipitation variables as explanatory factors of species richness in SA. To identify the sister lineages, we executed a phylogenetic reconstruction in RAxML for the North American clade in tribe Astereae analyzing genebank data of 8 markers and 494 species. For NA clade we selected 4 genera (35 species) and obtained 4525 occurrences of GBIF. For Haplopappus in SA, we used 1005 occurrences. For both ranges, we generated characterized background climates using random points. Climatic types in NA and SA were compared using multivariate analysis of PCA. Biogeographic patterns in SA were evaluated with nonlinear models, similarity analysis, source-sink dynamics and Bayesian analysis of endemism. Climatic drivers of species richness in SA were evaluated using spatial regressions. The close relatives of Haplopappus are Hazardia, Benitoa, Corethrogyne, and Lessingia. The climatic niches of the NA and SA species are overlapped, but each lineage present expanded niches along unique climatic space (not available in the other subcontinent). In Haplopappus the latitudinal and altitudinal pattern adjusts to the Gaussian distribution, the BAE showed two areas of endemism, North and South of 31° lat S, the nesting analysis showed source-sink dynamics and the explanatory variables were the seasonality of the temperature and the average temperature of the wettest quarter. Our results support partial climatic niche conservatism between the NA and SA species and a climatic niche expansion shaped by unique climatic variables associated to NA with isothermality, annual and daily thermal oscillations, and in SA associated with precipitations and maxima y minima temperature related to the Mediterranean biome, and expansion of some species to colder Patagonia steppe.

1 - Universidad de Concepción, Departamentos de Botánica, Casilla 160-C, Concepción, Chile, Concepción, Biobio, 4030000, Chile
2 - Universidad de Concepción, Departamento de Botánica, Casilla 160-C, Concepción, Chile, Concepción, Biobio, 4030000, Chile

Keywords:
Haplopappus
Astereae
Andes
climatic niche conservatism
long distance dispersal.

Presentation Type: Poster
Session: P, Biogeography Posters
Location: Virtual/Virtual
Date: Monday, July 27th, 2020
Time: 5:00 PM Time and date to be determined
Number: PBG005
Abstract ID:486
Candidate for Awards:None