Browsing by Autor "Alexandre Antonelli"

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Cinchona anderssonii (Rubiaceae), a new overlooked species from Bolivia
(Q15088586, 2017) Carla Maldonado; Claes Persson; Joaquina Albán Castillo; Alexandre Antonelli; Nina Rønsted
Cinchona anderssonii, a new species from the Yungas forests of the Andes in Bolivia, is described and illustrated. It is unique in Cinchona by having the combination of elliptic leaf blades glossy above, distinct circular pit domatia at secondary vein axils, basipetally dehiscent capsules, and relatively large seeds (8–11 mm long). A taxonomic key for the identification of the Cinchona species occurring in Bolivia is presented.
Endemic palm species shed light on habitat shifts and the assembly of the Cerrado and Restinga floras
(Elsevier BV, 2017) Christine D. Bacon; Mónica Moraes R.; Carlos Jaramillo; Alexandre Antonelli
Estimating species diversity and distribution in the era of <scp>B</scp>ig <scp>D</scp>ata: to what extent can we trust public databases?
(Wiley, 2015) Carla Maldonado; Carlos I. Molina; Alexander Zizka; Claes Persson; Charlotte M. Taylor; Joaquina Albán Castillo; Eder Chilquillo; Nina Rønsted; Alexandre Antonelli
Open databases and integrative bioinformatic tools allow a rapid approximation of large-scale patterns of biodiversity across space and altitudinal ranges. We found that geographic inaccuracy affects diversity patterns more than taxonomic uncertainties, often leading to false positives, i.e. overestimating species richness in relatively species poor regions. Public databases for species distribution are valuable and should be more explored, but under scrutiny and validation by taxonomic experts. We suggest that database managers implement easy ways of community feedback on data quality.
Good news for habitat restoration projects: Eucalyptus does not inhibit the germination of Polylepis
(Wiley, 2022) Lidia Meneses; Yvonne Y. Martinez; Alexandre Antonelli; Edgar E. Gareca
Eucalyptus plantations outside their native range—either as an income source or aimed at sequestering atmospheric carbon to combat climate change—are increasingly known to reduce local biodiversity and groundwater levels, and to increase soil degradation and erosion. One additional but less understood effect of Eucalyptus on native floras is allelopathy—the chemical inhibition of other plants' germination. Here we investigate the putative allelopathic effects of Eucalyptus globulus on the germination of Polylepis subtusalbida , a keystone species that characterizes a species‐rich and highly threatened woodland habitat in the Bolivian Andes. We carry out controlled greenhouse experiments reflecting local rainfall, field litter quantity, and Eucalyptus leachate concentrations at multiple levels. Our results, based on five replicates with 390 Polylepis seeds each, show that contrary to our expectation Eucalyptus leachates does not affect germination significantly. Our findings suggest that projects aiming to remove Eucalyptus to restore Polylepis woodlands are likely to succeed even without the resource‐consuming removal of leaf litter, and potentially also bark and roots, from the ground after tree felling.
Historical chemical annotations of Cinchona bark collections are comparable to results from current day high-pressure liquid chromatography technologies
(Elsevier BV, 2019) Nataly Allasi Canales; Tobias Gress; Claus Cornett; Kim Walker; Felix Driver; Alexandre Antonelli; Carla Maldonado; Mark Nesbitt; Christopher J. Barnes; Nina Rønsted
Phylogeny Predicts the Quantity of Antimalarial Alkaloids within the Iconic Yellow Cinchona Bark (Rubiaceae: Cinchona calisaya)
(Frontiers Media, 2017) Carla Maldonado; Christopher J. Barnes; Claus Cornett; Else Holmfred; Steen Honoré Hansen; Claes Persson; Alexandre Antonelli; Nina Rønsted
Considerable inter- and intraspecific variation with respect to the quantity and composition of plant natural products exists. The processes that drive this variation remain largely unknown. Understanding which factors determine chemical diversity has the potential to shed light on plant defenses against herbivores and diseases and accelerate drug discovery. For centuries, Cinchona alkaloids were the primary treatment of malaria. Using Cinchona calisaya as a model, we generated genetic profiles of leaf samples from four plastid (trnL-F, matK, rps16, and ndhF) and one nuclear (ITS) DNA regions from twenty-two C. calisaya stands sampled in the Yungas region of Bolivia. Climatic and soil parameters were characterized and bark samples were analyzed for content of the four major alkaloids using HPLC-UV to explore the utility of evolutionary history (phylogeny) in determining variation within species of these compounds under natural conditions. A significant phylogenetic signal was found for the content of two out of four major Cinchona alkaloids (quinine and cinchonidine) and their total content. Climatic parameters, primarily driven by changing altitude, predicted 20.2% of the overall alkaloid variation, and geographical separation accounted for a further 9.7%. A clade of high alkaloid producing trees was identified that spanned a narrow range of altitudes, from 1,100 to 1,350 m. However, climate expressed by altitude was not a significant driver when accounting for phylogeny, suggesting that the chemical diversity is primarily driven by phylogeny. Comparisons of the relative effects of both environmental and genetic variability in determining plant chemical diversity have scarcely been performed at the genotypic level. In this study we demonstrate there is an essential need to do so if the extensive genotypic variation in plant biochemistry is to be fully understood.
Plant biogeography of rock outcrops in South American tropical lowlands
(International Biogeography Society, 2025) Rosie Clegg; Luísa Azevedo; Maira T. Martinez-Ugarteche; Danilo M. Neves; Catherine Kidner; D. J. N. Hind; Alexandre Antonelli; Lucy Rowland; R. Toby Pennington
Studies of rock outcrops in tropical South America have increased in recent years, but they have often been restricted to individual countries, single biomes or single disciplines (e.g. through a floristic, functional or genetic lens), limiting their generality. We review the current state of knowledge on the geological and floristic diversity of rock outcrops in tropical South America to identify knowledge gaps and generate testable hypotheses for future research into the biogeography and evolution of their plant communities. We find that the diversity of lowland rock outcrop vegetation is disparately documented and we know less about the evolutionary and biogeographic history of these island-like systems. Based on geological and edaphic factors, we classify South American rock outcrops into four main groups: granite/gneiss, quartzite/metamorphosed sandstone, limestone and ironstone. We hypothesise that these lithologies influence the floristic and evolutionary lineage composition of outcrop floras. However, elevation also plays a role through creating microclimatic conditions and by influencing the degree of insularity from the surrounding vegetation. Our literature review suggests that these lithologies support different floras, but confirming this requires further floristic surveys across the full geological diversity of outcrops. We suggest a research framework to: (i) improve knowledge of outcrop floras and how they relate to floras of surrounding biomes; (ii) investigate the relative roles of niche conservatism and evolution using floristic and phylogenetic approaches; and (iii) assess how outcrop species cope with living in naturally fragmented habitats through analysis of recruitment and gene flow using population genetics. Understanding the biogeography of rock outcrop floras can help provide information for conservation planning and decisions. Rock outcrops are in urgent need of study because they possess a distinctive and highly specialised flora that is threatened by climate and land-use changes. There is a need to increase the number of studies in some Latin American countries (e.g. Bolivia, Paraguay, Guyana, French Guiana and Suriname) and lithologies (e.g. limestone). We suggest that the major determinant of floristic composition on rock outcrops is lithology and outline how this can be tested using community-level floristic data. Inferring the phylogenetic relationships of the species endemic to rock outcrops and establishing the environments where their closest relatives occur will be a powerful approach to address questions of niche evolution and niche conservatism in the historical assembly of outcrop floras. Population genetic approaches focusing on plant species that occur both in outcrop habitats and the surrounding vegetation will elucidate their connectivity and, therefore, how insular and vulnerable these environments are.
Setting priorities for the acquisition of primary plant occurrence data
(2025) Nadia Bystriakova; Pablo Hendrigo Alves de Melo; Alexandre Antonelli; Steven P. Bachman; Gemma L. C. Bramley; Matilda J. M. Brown; Gloria Céspedes; Martin Cheek; Iain Darbyshire; Sebsebe Demissew
Abstract Aim Effective implementation of the Global Biodiversity Framework and Global Strategy for Plant Conservation depends on accurate species distribution data. Current vascular plant distribution data, while crucial for understanding terrestrial ecosystems, is often sparse and biased and requires significant expansion. This study developed a scalable approach to prioritize areas for plant occurrence data acquisition, adaptable to national priorities and providing a framework for botanical institutions to coordinate efforts and allocate resources. Location Global. Methods Using a Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) analysis, we prioritized areas based on: (a) ecosystem service value; (b) floristic value threatened by climate or land-use change; and (c) uncertainty in species richness estimates, stratified by biome and region. Regional prioritization maps for Africa & Madagascar; East, South and Southeast Asia; Siberia and the Russian Far East; South America; and North & Central America were reviewed by botanical experts for validation. Scalability was assessed by comparing regional and global analyses. Results Data-driven priority maps, divided into tree-dominated and grassland/deforested areas, largely received expert support. High similarity between global and regional maps demonstrated scalability. Main conclusions Our approach provides a framework for supporting national implementation of the Global Biodiversity Framework. Variables and their weights can be tailored to national or local needs. The method’s flexibility and adaptability extend to other taxonomic groups and objectives, such as protected area selection By prioritizing data acquisition, whether field-based or digital, this research promotes the efficient use of resources. A key advantage of this approach is its capacity to systematically translate expert opinion into explicit and quantitative criteria, which in turn facilitates clear communication with policymakers and funders.
Unexpectedly High Beta-Diversity of Root-Associated Fungal Communities in the Bolivian Andes
(Frontiers Media, 2016) Christopher J. Barnes; Carla Maldonado; Tobias Guldberg Frøslev; Alexandre Antonelli; Nina Rønsted
Bolivia is one of the most biologically diverse countries on the planet. Between the Andes and the Amazon drainage basin spans the Yungas, a vast forested region shown to be extremely species rich in macro-organisms. However, it remains unclear whether this high diversity is also reflected in microbial diversity. Here we assess the genetic, taxonomic and functional diversity of root-associated fungi surrounding Cinchona calisaya trees, a typical element of the intermediate altitudes of the Bolivian Yungas. We determine the relative effects of edaphic properties, climate, and geography in regulating fungal community assembly. We show that α-diversity for these fungal communities was similar to temperate and arid ecosystems, averaging 90.1 operational taxonomic units (OTUs) per sample, with reads predominantly assigned to the Ascomycota phylum and with a saprotrophic lifestyle. ß-diversity was calculated as the distance-decay rate, and in contrast to α-diversity, was exceptionally high with a rate of -0.407. Soil properties (pH and P) principally regulated fungal community assembly in an analogous manner to temperate environments, with pH and phosphorus explaining 7.8 and 7.2% of community variation respectively. Surprisingly, altitude does not influence community formation, and there is limited evidence that climate (precipitation and temperature) play a role. Our results suggest that sampling should be performed over a wide geographical and environmental range in order to capture the full root-associated fungal diversity in subtropical regions. This study sheds further light on the diversity and distribution of the world's "hidden biodiversity."