Plant dispersal strategies of high tropical alpine communities across the Andes

Dispersal is a key ecological process that influences plant community assembly. Therefore, understanding whether dispersal strategies are associated with climate is of utmost importance, particularly in areas greatly exposed to climate change. We examined alpine plant communities located in the mountain summits of the tropical Andes across a 4,000-km latitudinal gradient. We investigated species dispersal strategies and tested their association with climatic conditions and their evolutionary history. We used dispersal-related traits (dispersal mode and growth form) to characterize dispersal strategies for 486 species recorded on 49 mountain summits. Then we analysed the phylogenetic signal of traits and investigated the association between dispersal traits, phylogeny, climate and space using structural equation modelling and fourth-corner analysis together with RLQ ordination. A median of 36% species in the communities was anemochorous (wind-dispersed) and herbaceous. This dispersal strategy was followed by the barochory-herb combination (herbaceous with unspecialized seeds, dispersed by gravity) with a median of 26.3% species in the communities. The latter strategy was common among species with distributions restricted to alpine environments. While trait states were phylogenetically conserved, they were significantly associated with a temperature gradient. Low minimum air temperatures, found at higher latitudes/elevations, were correlated with the prevalence of barochory and the herb growth form, traits that are common among Caryophyllales, Brassicaceae and Poaceae. Milder temperatures, found at lower latitudes/elevations, were associated with endozoochorous, shrub species mostly from the Ericaceae family. Anemochorous species were found all along the temperature gradient, possibly due to the success of anemochorous Compositae species in alpine regions. We also found that trait state dominance was more associated with the climatic conditions of the summit than with community phylogenetic structure. Although the evolutionary history of the tropical Andean flora has also shaped dispersal strategies, our results suggest that the environment had a more predominant role. Synthesis. We showed that dispersal-related traits are strongly associated with a gradient of minimum air temperatures in the Andes. Global warming may weaken this key filter at tropical alpine summits, potentially altering community dispersal strategies in this region and thus, plant community structure and composition.Fil: Tovar, Carolina. Royal Botanic Gardens; Reino UnidoFil: Melcher, Inga. University of Amsterdam; Países BajosFil: Kusumoto, Buntarou. Royal Botanic Gardens; Reino Unido. University Of The Ryukyus, Okinawa; JapónFil: Cuesta, Francisco. Universidad de Las Américas.; EcuadorFil: Cleef, Antoine. University of Amsterdam; Países BajosFil: Meneses, Rosa Isela. Universidad Católica del Norte; ChileFil: Halloy, Stephan. Ministry For Primary Industries; Nueva ZelandaFil: Llambi, Luis Daniel. Universidad de Los Andes; VenezuelaFil: Beck, Stephan G.. Universidad Mayor de San Andrés; BoliviaFil: Muriel, Priscilla. Pontificia Universidad Católica del Ecuador; EcuadorFil: Jaramillo, Ricardo Luis. Pontificia Universidad Católica del Ecuador; EcuadorFil: Jacome, Jorge. Pontificia Universidad Javeriana; ColombiaFil: Carilla, Julieta. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; Argentin

Molecular Mechanisms of Resistance to Antifungals in <em>Candida albicans</em>

Invasive Candidiasis (IC) presents a global mortality rate greater than 40%, occupying the fourth place worldwide as the most frequent opportunistic nosocomial disease. Although the genus Candida consists of around 200 species, only 20 are reported as etiological agents of IC, being Candida albicans the most frequent causal agent. Even when there is a broad range of antifungals drugs for Candida infections, azoles, polyenes, and echinocandins are considered among the most effective treatment. However, there is some incidence for antifungal resistance among some Candida strains, limiting treatment options. Several molecular mechanisms with antifungal agents have been reported for C. albicans where insertions, deletions, and point mutations in genes codifying target proteins are frequently related to the antifungal drug resistance. Furthermore, gene overexpression is also frequently associated to antifungal resistance as well as an increase in the activity of proteins that reduce oxidative damage. This chapter summarizes the main molecular mechanisms to C. albicans antifungal drug resistance, besides offering an overview of new antifungal agents and new antifungal targets to combat fungal infections

BIOTHAW: Un proyecto multidisciplinario que propone un marco metodológico para el estudio de los bofedales altoandinos en un contexto de cambio climático

National audienceBIOTHAW: Un proyecto multidisciplinario que propone un marco metodológico para el estudio de los bofedales altoandinos en un contexto de cambio climático BIOTHAW: A multidisciplinary project proposing a methodological framework for the study of high-Andean wetlands in the context of climate change Resumen A pesar que las montañas tropicales son uno de los biomas más amenazados del mundo, es escasa la investigación fundamental y aplicada sobre los efectos de los cambios globales en la biodiversidad y los beneficios de los ecosistemas. Las zonas húmedas de los ambientes altoandinos tropicales-los bofedales-son espacios verdes dentro de una matriz árida que concentran una rica biodiversidad y variedad de beneficios asociados (almacenamiento de carbono, regulación de agua y producción de ganado), de los que dependen millones de personas. Estos frágiles ecosistemas están amenazados por la rapidez del derretimiento de los glaciares de los cuales dependen significativamente. El proyecto BIOTHAW-Biodiversidad e interacciones de uso de los suelos frente a la evolución de la disponibilidad de agua de los glaciares en las zonas húmedas de los Andes tropicales-tiene por objetivo desarrollar un marco de modelización para establecer escenarios de biodiversidad y uso de las tierras en un contexto de cambios globales. El enfoque del proyecto integra tres componentes: 1) la modificación de los aportes de agua glaciares a las zonas húmedas, 2) la biodiversidad (animal y vegetal) de estas zonas y 3) las prácticas de cultivo (patrones de utilización de las tierras, dinámica de las estructuras de la ganadería). Nutridos por escenarios climáticos y socioeconómicos, los diferentes modelos combinados con mapas de distribución de las zonas húmedas permitirán establecer escenarios de la biodiversidad y los servicios de los bofedales, con el fin de definir zonas prioritarias de conservación

Comunidades vegetales de los bofedales de la Cordillera Real (Bolivia) bajo el calentamiento global

International audienceHigh-Andean wetlands (bofedales) are one of the most threatened ecosystems in the face of global warming. Given the close relationship between bofedales and water, it is expected that glacial retreat will cause their gradual shrinkage. With three proxies of climate change (bofedal area, glacier influence and elevation) we inferred how these changes may affect plant communities. The hypotheses were 1) that loss in the area of bofedales should reduce plant diversity - the glacier influence and elevation could affect this relationship through effect on environmental heterogeneity and diversity - and 2) glacial retreat may indirectly affect diversity through changes in dominant species. We measured ? and ? additive diversity of plants in 20 bofedales (>4.400 m) in the Cordillera Real (Bolivia). Sixty three species were found (species richness: 5-22 /plot 1 m2). Variations in bofedales área and glacial influence weren't correlated with vegetation changes whereas diversity reduced at higher elevation. In reference to our second hypothesis, leaves of Oxychloe andina were shown more resistant to drought stress because of its higher leaf dry mass content (LDMC) than the other cushions, indicating that the bofedales dominated by O. andina may be drier and the communities are dominated by species that also can be found in drier environments. In contrast, communities of Distichia spp. are less tolerant to water déficit. If glacial retreat reduces water availability in the coming decades, the bofedales of O. andina may be more abundant at the expense of Distichia spp. creating challenges for the biodiversity conservationLos humedales altoandinos (bofedales) son uno de los más amenazados frente al calentamiento global. Dada la estrecha relación entre bofedales y agua, el retroceso glacial podrá causar su contracción. Con tres proxis del cambio climático (área de bofedales, influencia glaciar y altitud) se infirió indirectamente cómo éstos pueden afectar a las comunidades vegetales. Las hipótesis fueron 1) que la reducción del área del bofedal podría afectar negativamente la diversidad de plantas - la influencia glaciar y la altitud podrían afectar ésta relación por su efectos en la heterogeneidad ambiental y la diversidad – y 2) que el retroceso glacial puede afectar indirectamente la diversidad a través de cambios en las especies dominantes. Se midió la diversidad α y β aditiva de plantas en 20 bofedales (>4.400 m) de la Cordillera Real (Bolivia). Se encontraron 63 especies (riqueza especifica: 5-22/cuadrante 1m²). Variaciones del área e influencia glacial no se relacionaron con cambios en la vegetación, pero la diversidad fue menor a mayor altitud. Las hojas de Oxychloe andina son más resistentes al estrés ambiental por su mayor masa foliar seca, a diferencia de Distichia spp., indicando que los bofedales dominados por O. andina son más secos. Además tienen más especies que también se pueden encontrar en las laderas. Mientras, las comunidades de Distichia spp. son menos tolerantes al déficit hídrico. Si el retroceso glacial reducirá el agua en las próximas décadas, el bofedal de O. andina podrá ser más abundante a expensas de los de Distichia spp., generando desafíos para la conservación. Oxychloe andina , Retroceso glacial

Cushion-plant protection determines guild-dependent plant strategies in high-elevation peatlands of the Cordillera Real, Bolivian Andes

International audienceThe functional trait composition of plant communities reflects the influence of ecological constraints on their assembly. In high-elevation peatlands of the Andes, multiple abiotic and biotic stresses are exerted on herbaceous plant communities. We hypothesized that dominant cushion-plant species found in these ecosystems strongly influence the dynamics of their subordinate plants by providing protection against external stress. To test the hypothesis, we addressed the variation of functional traits reflecting how subordinate plants invest in durable tissues and develop below and above the canopy of two cushion-plant species dominating the ecosystem, with varying intensity of herbivore pressure. We expected different functional composition of plants living below (understory stratum) and above (emergent stratum) the canopy, related to cushion-plant protection. In addition, we considered the functional composition of basic morphological guilds, forbs and graminoids, as they invest differently in plant development and respond differently to herbivore pressure. We found contrasted functional compositions among morphological guilds and according to the position relatively to cushion-plant canopy. These variations support a protective influence of cushion-plants on subordinate plants for both strata, with investment into less costly leaves and a larger stature when protection is greater, depending on cushion-plant species and cushion-plant height. External stress mainly affected emergent plants and led to different responses according to the guild. Graminoids showed avoidant strategy, while forbs shifted from avoidant to tolerant strategy with increasing herbivore pressure. Both between-species and intraspecific trait variations contributed to explain functional changes of guilds, but the relative contributions depended on morphological guild and stratum. A basic trade-off in physiological and morphological variability determined different relative contribution in forbs and graminoids. While functional ecology classically focuses on the composition of spatially delimited communities, we here underline the need to address separately the functional composition and assembly dynamics of distinct guilds making a community. In addition, our survey is the first to investigate the functional ecology of high-elevation tropical peatlands and provides novel insights into vegetation ecology in this stressful ecosystem

Ecosistemas alto-andinos del valle de La Paz: aportes a la sociedad y vulnerabilidad frente a los cambios globales

capitulo 8International audienc

Data from: Ecotypic differentiation under farmers’ selection: molecular insights into the domestication of Pachyrhizus Rich. ex DC. (Fabaceae) in the Peruvian Andes

Understanding the distribution of crop genetic diversity in relation to environmental factors can give insights into the eco-evolutionary processes involved in plant domestication. Yam beans (Pachyrhizus Rich. ex DC.) are leguminous crops native to South and Central America that are grown for their tuberous roots but are seed-propagated. Using a landscape genetic approach, we examined correlations between environmental factors and phylogeographic patterns of genetic diversity in Pachyrhizus landrace populations. Molecular analyses based on chloroplast DNA sequencing and a new set of nuclear microsatellite markers revealed two distinct lineages, with strong genetic differentiation between Andean landraces (lineage A) and Amazonian landraces (lineage B). The comparison of different evolutionary scenarios for the diversification history of yam beans in the Andes using Approximate Bayesian Computation (ABC) suggests that P. ahipa and P. tuberosus share a progenitor-derivative relationship, with environmental factors playing an important role in driving selection for divergent ecotypes. The new molecular data call for a revision of the taxonomy of Pachyrhizus but are congruent with palaeoclimatic and archaeological evidence, and suggest that selection for determinate growth was part of ecophysiological adaptations associated with the diversification of the P. tuberosus–P. ahipa complex during the Mid-Holocene

Ecotypic differentiation under farmers' selection: Molecular insights into the domestication of Pachyrhizus Rich. ex DC. (Fabaceae) in the Peruvian Andes

La comprensión de la distribución de la diversidad genética de los cultivos en relación con los factores ambientales puede dar una idea de los procesos eco-evolutivos involucrados en la domesticación de las plantas. La jícama (Pachyrhizus Rich. ex DC.) es un conjunto de leguminosas cultivadas nativas de América del Sur y Central que se cultivan por sus raíces tuberosas pero son propagadas por semillas. Utilizando un enfoque genético de paisaje, examinamos las correlaciones entre los factores ambientales y los patrones filogeográficos de diversidad genética en las poblaciones de Pachyrhizus landrace. Los análisis moleculares basados en la secuenciación del ADN del cloroplasto y un nuevo conjunto de marcadores de microsatélites nucleares revelaron dos linajes distintos, con una fuerte diferenciación genética entre las razas locales andinas (linaje A) y las amazónicas (linaje B). La comparación de diferentes escenarios evolutivos para la historia de la diversificación del ñame en los Andes utilizando cálculos bayesianos aproximados sugiere que Pachyrhizus ahipa y Pachyrhizus tuberosus comparten una relación progenitora derivada, con factores ambientales que juegan un papel importante en la selección de ecotipos divergentes. Los nuevos datos moleculares requieren una revisión de la taxonomía de Pachyrhizus pero son congruentes con la evidencia paleoclimática y arqueológica, y sugieren que la selección para un crecimiento determinado fue parte de las adaptaciones ecofisiológicas asociadas con la diversificación del complejo P. tuberosus y P. ahipa durante el Holoceno medio.Revisado por pare

Data from: Ecotypic differentiation under farmers’ selection: molecular insights into the domestication of Pachyrhizus Rich. ex DC. (Fabaceae) in the Peruvian Andes

Understanding the distribution of crop genetic diversity in relation to environmental factors can give insights into the eco-evolutionary processes involved in plant domestication. Yam beans (Pachyrhizus Rich. ex DC.) are leguminous crops native to South and Central America that are grown for their tuberous roots but are seed-propagated. Using a landscape genetic approach, we examined correlations between environmental factors and phylogeographic patterns of genetic diversity in Pachyrhizus landrace populations. Molecular analyses based on chloroplast DNA sequencing and a new set of nuclear microsatellite markers revealed two distinct lineages, with strong genetic differentiation between Andean landraces (lineage A) and Amazonian landraces (lineage B). The comparison of different evolutionary scenarios for the diversification history of yam beans in the Andes using Approximate Bayesian Computation (ABC) suggests that P. ahipa and P. tuberosus share a progenitor-derivative relationship, with environmental factors playing an important role in driving selection for divergent ecotypes. The new molecular data call for a revision of the taxonomy of Pachyrhizus but are congruent with palaeoclimatic and archaeological evidence, and suggest that selection for determinate growth was part of ecophysiological adaptations associated with the diversification of the P. tuberosus–P. ahipa complex during the Mid-Holocene

Data used for figure production of "<b>Carbon dynamics in high-Andean tropical cushion peatlands: A review of geographic patterns and potential drivers"</b>

These data have been used to produce the figures of the manuscript "Carbon dynamics in high-Andean tropical cushion peatlands: A review of geographic patterns and potential drivers", authored by Mary Carolina García Lino1,2*, Simon Pfanzelt3,4, Alejandra I. Domic2,5,6, Isabell Hensen1,7, Karsten Schittek8, Rosa Isela Meneses2,9, & Maaike Y. Bader10, which has been submitted to Ecological Monographs.1Institute of Biology/Geobotany and Botanical Garden, Martin Luther University of Halle-Wittenberg, Halle, Germany; 2Herbario Nacional de Bolivia, Instituto de Ecología, Universidad Mayor de San Andrés, La Paz, Bolivia; 3Botanic Garden Munich-Nymphenburg, Bavarian Natural History Collections, Munich, Germany; 4Experimental Taxonomy, Leibniz Institute of Plant Genetics and Crop Plant Research, Gatersleben, Germany; 5Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA; 6Department of Anthropology, Pennsylvania State University, University Park, PA 16802, USA; 7German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany; 8Institute of Geography Education, University of Cologne, Cologne, Germany; 9Instituto de Arqueología y Antropología, Universidad Católica del Norte, San Pedro, Chile; 10Ecological Plant Geography, Faculty of Geography, University of Marburg, Marburg, Germany.Details of the figuresFigure 1. Data for producing a map of tropical and subtropical Andean South America, depicting the geographic location of cushion peatland study sites at which data on C stocks, C fluxes or both variables were generated.Figure 2. Latitudinal distribution of representative plant species of Andean cushion peatlands. Data were drawn from GBIF.org on 20 July 2023 and checked for plausibility, retaining only records based on specimen data from herbaria.Figure 3. Peat-core age and carbon accumulation rate (ARCA) in high-Andean cushion peatlands across páramo, wet and dry puna. The number of peat cores is n= 22 for páramo, 10 for wet puna, and 11 for dry puna.Figure S1. Models of temporal development of sediment accumulation rates (yr cm-1) for peat cores from high-Andean tropical cushion peatlands.</p