Federico Luebert’s research while affiliated with University of Santiago Chile and other places

The post-Miocene climatic history of arid environments in South America has been identified as a key driver of dispersal and diversification, particularly among plant groups such as Cactaceae. Despite their iconic status, many cactus genera remain poorly understood, and comprehensive taxonomic and systematic revisions using morphological and genomic data are complex and timeconsuming, resulting in few such studies to date. Here we present a comprehensive systematic study of the genus Austrocactus, currently with 10 accepted species native to southern and Andean Argentina and parts of Chile. The study is based on an extensive sampling covering both the overall range and the morphological diversity of the genus. We used a ddRADseq approach to study phylogenetic relationships incorporating 44 individuals representing all morphospecies, and widespread species are represented by several samples covering their morphological and geographical spectrum. The data were analyzed using maximum likelihood and multispecies coalescence-based models, as well as principal component analyses, providing awell-supported and robust evolutionary framework. Based on phylogenetic and morphological data,we propose a revised classification of the genus, with a total of 17 species, 5 of which are described as new. We also provide an updated infrageneric classification with two subgenera and three sections, and a revised circumscription of the genus, including descriptions of all species, as well as a respective key. Finally, we suggest specific research directions focused on integrating genomic data with ecological modeling to complement our work and enhance the biogeographic understanding of these species.

The campos rupestres and the Brazilian Atlantic Forest Inselbergs (BAFI) are highly diverse vegetation types that grow on mountaintops of eastern Brazil and show outstanding levels of endemism. The plant family Velloziaceae is an iconic element of these vegetations, with the genus Vellozia, being exceptionally abundant in both these vegetations. In this study, we use Vellozia as a model to address three main questions: (i) What was the distribution of Vellozia’s most recent common ancestor? (ii) Did the range expansions of Vellozia occur during periods characterized by global cooling? (iii) When did Vellozia colonize the different South American highlands they occupy nowadays? To address these questions, we reconstructed the phylogeny of Vellozia using sequences of four molecular markers analysed using Bayesian and maximum likelihood inferences. We used the resulting phylogeny to reconstruct the ancestral distribution of Vellozia using the DEC model. Our findings indicate that Vellozia originated and subsequently diversified in the Oligocene, when the genus was broadly distributed through the Andes, BAFI, Cerrado, Caatinga, and the Chapada Diamantina, suggesting that the Cerrado may acted as a corridor between the Andes and eastern mountaintop vegetations. Vellozia subsequently occupied the southern Espinhaço during the Early Miocene, which was followed by increased diversification rates and several range expansions, especially after the Middle-Miocene Climatic Optimum, when cooler and drier periods allowed the expansion of open environments and the retraction of forests, allowing Vellozia to expand their distribution. These results highlight the unique evolutionary history of Vellozia and the importance of climatic cooling for the expansion of the genus.

Spatial patterns of phylogenetic diversity (PD) are increasingly becoming relevant for conservation decisions. PD measures are based on phylogenies estimated from molecular data. This paper addresses the question of how different molecular markers impact PD spatial patterns. We first conducted a simple simulation to explore the effect of deep and shallow changes in topology (simulating variations in molecular markers), using ultrametric and non-ultrametric trees, and then used a dataset of Chilean flora with four sets of markers to assess potential differences in spatial patterns of PD ranks using different markers and types of trees. The simulation consistently showed that the difference in PD rank was lower for ultrametric trees than for phylograms. A similar trend was observed using the Chilean flora dataset, with among-markers variability in spatial patterns of the PD metrics lower for ultrametric than for non-ultrametric trees, depicted as top 2.5 and 5% hotspots. Frequency distribution of PD values differed among markers as well, with this variation less apparent for ultrametric trees. We conclude that the choice of markers impacts spatial patterns of PD, and these results vary more strongly for phylograms, suggesting that ultrametric trees are more robust to the choice of marker.

The Atacama Desert is a biodiversity hotspot of neo-endemic radiation, where long-term aridity and complex physiographic processes create a unique environmental setting. Current species assemblages are mainly concentrated in highly patchy loma formations, and plant populations occurring in these are often geographically isolated from each other. Despite a general consensus on long-term aridity in the Atacama, climatological and geological evidence points to repeated climate change, making the Atacama Desert an ideal system for studying population genetic processes in highly unstable habitats. We are analyzing the genetic structure within and between populations of Huidobria fruticosa, a paleo-endemic lineage of the Atacama Desert, to shed new light on its biogeographic history and broaden our understanding of the evolution of life in extreme aridity, as well as plant evolution in response to a changing environment. To do this, we analyzed SNP data from genotyping-by-sequencing of 354 individuals from 21 populations. Our results suggest that, despite being an ancient lineage, the current population structure of Huidobria fruticosa only reflects changing abiotic conditions over the last 2 million years. We therefore conclude that the present distribution, together with the evolutionary processes documented here, is the result of climatic fluctuations and prolonged periods of hyperaridity during the Pleistocene. Building on this understanding, our findings contribute to a global narrative that highlights the complex interplay between climate change and evolutionary dynamics, and emphasize the importance of deserts as living laboratories for deciphering how species have historically adapted to some of the most extreme habitats on Earth.

Background and Aim Plant disjunctions have fascinated biogeographers and ecologists for a long time. We use tribe Bocageeae (Annonaceae), a predominantly Neotropical plant group distributed across several present-day Neotropical biomes and with an African-American disjunction, to investigate long-distance dispersal mediated by frugivorous animals at both intercontinental and intracontinental scales. Methods We reconstructed a species-level phylogeny of tribe Bocageeae with a dataset composed of 116 nuclear markers. We sampled 70% of Bocageeae species, covering its geographic range and representing all eight genera. We estimated divergence times using BEAST, inferred ancestral range distributions and reconstructed ancestral states for fruit traits related to long-distance dispersal in a Bayesian framework. Key Results The ancestral Bocageeae date to the Early Eocene and were inferred to occur in Africa and proto-Amazonia. Its ancestral fruits were large and dehiscent. The first lineage split gave rise to an exclusively Neotropical clade during the Middle Eocene, in proto-Amazonia. Range exchange between the Amazon and the Atlantic Forest occurred at least once during the Miocene, and from Amazonia to Central America and Mexico, during the Early Miocene. Transitions in different sets of fruit morphologies were inferred to be related to dispersal events across South American regions/biomes. Conclusions In Bocageeae mammals may have been responsible for long-distance dispersal through the Boreotropics. In the Neotropics, proto-Amazonia is proposed to be the source for dispersal to other tropical American biomes. Long-distance dispersal may have happened via a wide range of dispersal guilds, depending on frugivore radiations, diversity, and abundance at particular time periods and places. Hence, inter- and intracontinental dispersal may not rely on a single dispersal syndrome or guild, but more on the availability of frugivorous lineages for seed dispersal.

The classic and current perception of biome in its various meanings is fundamentally based on vegetation types that are considered as discrete or independent and fragmented entities in the landscape. Vegetation units are characterized by their physiognomy, which is based on the dominant life forms and mainly determined by climatic conditions. However, vegetation units are associated and mutually interacting at a landscape level. They are determined by local or regional, climatic, topographic and edaphic gradients within a given territory or geographic area. In this work, we propose a new conceptual and methodological approach aiming to better understand the biome concept in a landscape framework, developing ideas already partially advanced by us. In this sense, we consider the biome as a landscape complex (geocomplex), that spatially includes one to several vegetation geoseries which, in turn, each comprise the following possible geomorphologically linked vegetation series: i) the potential natural climatophilic vegetation (zonal vegetation) and their seral successional stages which occur repeatedly in the landscape; ii) edapho-xerophyllous vegetation (azonal vegetation such as occurs on rocky outcrops or sandy soils); and iii) edapho-hygrophilic vegetation (azonal vegetation such as flooded vegetation on river banks). Based on surveys and field data (more than ca. 300 transects) obtained by the authors in most South American countries from 1990 to the present, 33 South American geocomplex biomes and 16 macrobiomes were identified and synoptically characterized, through graphic general zonation models (phyto-topographic type-profiles) extrapolated from numerous observations along representative bioclimatical, geomorphological and biogeographically stratified transects. Field data and transect-plots are currently being processed to be included into the “GIVD database”

In the era of Big Data, Latin American countries and biomes remain underrepresented. To remediate this issue, promoting repositories for biodiversity data focused on Latin America is a main priority. VegAndes -Dpt the vegetation database for the Latin American highlands (GIVD: SA-00-005), is a novel dataset for georeferenced and standardized information on vascular pants in the region. The database compiles 5,340 vegetation plots sampled above the montane treeline and below the permanent snowline in 11 Latin American countries and spanning over seven decades. VegAndes currently encompasses 5,804 taxon names, corresponding to 3,858 accepted names, as well as 136 syntaxon names. The database is nested within a scientific consortium of Latin American experts on highland vegetation and piloted from the University of the Andes (Colombia). Because the VegAndes data can support multi-scale studies in botany, ecology and biogeography, the database makes an essential contribution to biodiversity research and management perspectives in Latin America. Taxonomic reference : TROPICOS (preferential source, www.tropicos.org/), World Flora Online (secondary source, www.worldfloraonline.org/).

Checklist of syntaxa recorded for the Chilean vegetation according to the Braun-Blanquet approach and supported by vegetation-plot observations in the database "sudamerica".

Detailed list of data sources for plot observations recorded for the Chilean vegetation and stored in the database "sudamerica".

In this study we aim at refining our understanding of the floristic connectivity of the loma- and precordillera floras of southern Peru and northern Chile and the parameters determining vegetation cover in this region. We used multivariate analyses to test for floristic- and environmental similarity across 53 precordillera and loma locations in Peru and Chile. We propose the use of predictive modeling in estimating the extent of desert vegetation as a complementary method to remote sensing. We created habitat suitability models for the vegetation on the coast and in the precordillera based on a combination of latent bioclimatic variables and additional environmental predictors using Maxent. We found Peruvian and Chilean lomas to be strongly floristically differentiated, as are the Chilean precordillera and lomas. Conversely, there is clear connectivity between both the Peruvian loma- and precordillera floras on the one hand and the Peruvian and Chilean precordillera floras on the other. Divergent environmental conditions were retrieved as separating the precordillera and lomas, while environmental conditions are not differentiated between Peruvian and Chilean lomas. Peruvian and Chilean precordilleras show a gradual change in environmental conditions. Habitat suitability models of vegetation cover retrieve a gap for the loma vegetation along the coast between Peru and Chile, while a continuous belt of suitable habitats is retrieved along the Andean precordillera. Unsuitable habitat for loma vegetation north and south of the Chilean and Peruvian border likely represents an ecogeographic barrier responsible for the floristic divergence of Chilean and Peruvian lomas. Conversely, environmental parameters change continuously along the precordilleras, explaining the moderate differentiation of the corresponding floras. Our results underscore the idea of the desert core acting as an ecogeographic barrier separating the coast from the precordillera in Chile, while it has a more limited isolating function in Peru. We also find extensive potentially suitable habitats for both loma- and precordillera vegetation so far undetected by methods of remote sensing.