178 research outputs found

    Informe de gestión 2017-2020

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    Este documento reseña la gestión del Banco de la República entre 2017 y 2020, un período durante el cual el Banco logró consolidar una inflación baja y estable, con tasas de crecimiento cada vez más cercanas al potencial. A partir de marzo de 2020 se adoptaron políticas novedosas que lograron evitar una crisis profunda en medio de la pandemia del Coronavirus, un choque de enormes dimensiones para la humanidad. De otra parte, se tomaron medidas importantes tendientes a fortalecer la Administración del Banco, con un mayor control de los recursos financieros destinados a los distintos objetivos del Plan de Desarrollo. El Banco continúa siendo la institución estatal independiente que genera mayor confianza entre los colombianos por su transparencia, su ajuste a exigentes metas de resultados macroeconómicos y empresariales, y por el cumplimiento efectivo de las funciones de banca central y culturales encomendadas por la Constitución y la ley. RESUMEN EJECUTIVO La economía colombiana enfrentó en los últimos cuatro años algunos de los eventos que mayor impacto han tenido sobre su desempeño en más de un siglo. El precio internacional del petróleo cayó a menos de la tercera parte entre junio de 2014 y enero de 2016 y, nuevamente, entre septiembre de 2018 y abril de 2020; se presentaron frecuentes choques en el precio local de los alimentos, y la pandemia reciente ocasionó uno de los mayores desastres que ha padecido la humanidad en su historia. El Banco de la República (Banrep), sus directivos y empleados tuvieron que responder rápidamente a las nuevas circunstancias, un proceso que ha implicado grandes cambios en la forma como se han ejecutado y cumplido las funciones de la banca central y las del área cultural a cargo de la organización. De otra parte, el Plan Estratégico 2017-2021 sentó las bases para el nuevo programa de modernización del Banco, y en el presente Informe de gestión 2017-2020 se describen y analizan los retos enfrentados en el período y la forma en que se adaptó y modernizó la institución para hacerles frente. También se mencionan los principales desafíos que se avizoran hacia el futuro, con el fin de contribuir al diseño de los planes de la administración entrante. En este Resumen ejecutivo se presenta una síntesis del documento completo. En la sección II se hace un recuento de la situación económica de Colombia y el mundo en el cuatrienio reciente, y las medidas de política adoptadas por la Junta Directiva del Banco de la República (JDBR) para mantener la inflación baja y estable y contribuir a la recuperación del crecimiento de la economía. En la sección III se registran los avances y logros en los temas estratégicos del Plan Estratégico 2017-2021. En particular, se mencionan la política monetaria y de estabilidad financiera, la política cambiaria, la política de pagos, y otros temas relacionados con la eficiencia y eficacia en el Plan. La sección IV está dedicada a la gestión cultural, y en la sección V se describe la evolución de los temas de apoyo táctico para el logro de los objetivos del Plan: capital humano y cultura organizacional, tecnología e infraestructura; se incluye, además, un resumen de los avances en materia ambiental. En la sección VI se presentan los principales elementos de la respuesta del Banco ante la emergencia sanitaria del COVID-19. En la sección VII se describe el manejo de las reservas internacionales y se analizan el presupuesto y las utilidades del Banco. En la sección VIII se enuncian algunos desafíos futuros

    Las ciencias sociales en el noreste de México.

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    Texto colectivo que incluye seis ensayos donde se reflexiona sobre el estado que guardan las ciencias sociales en el noreste de México: antropología, comunicación, economía, geografía, historia y sociología.Redactado por miembros del Grupo Gente (Grupo de Estudios sobre el Noreste de México y Texas) bajo la coordinación de César Morado y Lucila Hinojosa

    Local hydrological conditions influence tree diversity and composition across the Amazon basin

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    Tree diversity and composition in Amazonia are known to be strongly determined by the water supplied by precipitation. Nevertheless, within the same climatic regime, water availability is modulated by local topography and soil characteristics (hereafter referred to as local hydrological conditions), varying from saturated and poorly drained to well-drained and potentially dry areas. While these conditions may be expected to influence species distribution, the impacts of local hydrological conditions on tree diversity and composition remain poorly understood at the whole Amazon basin scale. Using a dataset of 443 1-ha non-flooded forest plots distributed across the basin, we investigate how local hydrological conditions influence 1) tree alpha diversity, 2) the community-weighted wood density mean (CWM-wd) – a proxy for hydraulic resistance and 3) tree species composition. We find that the effect of local hydrological conditions on tree diversity depends on climate, being more evident in wetter forests, where diversity increases towards locations with well-drained soils. CWM-wd increased towards better drained soils in Southern and Western Amazonia. Tree species composition changed along local soil hydrological gradients in Central-Eastern, Western and Southern Amazonia, and those changes were correlated with changes in the mean wood density of plots. Our results suggest that local hydrological gradients filter species, influencing the diversity and composition of Amazonian forests. Overall, this study shows that the effect of local hydrological conditions is pervasive, extending over wide Amazonian regions, and reinforces the importance of accounting for local topography and hydrology to better understand the likely response and resilience of forests to increased frequency of extreme climate events and rising temperatures

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2^{2} = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2^{2} = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

    Mapping density, diversity and species-richness of the Amazon tree flora

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    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution

    Consistent patterns of common species across tropical tree communities

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    Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

    Vocabulario de la sociedad civil, la ruralidad y los movimientos sociales en América Latina

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    El Vocabulario de la Sociedad Civil, la Ruralidad y los Movimientos Sociales en América Latina tiene como objetivo desarrollar vocablos relacionados con temas de gran trascendencia para la vida colectiva de la población Latinoamericana; pretende introducir a estudiantes, personas del ámbito académico y activistas en la comprensión de estas categorías de análisis. A través de la mirada de 70 especialistas que participaron en este vocabulario, es posible comprender muchos de los términos que se utilizan dentro de la investigación social y áreas relacionadas con las ciencias políticas, ambientales y rurales, a partir de una mayor explicación y detalle. Es por ello que se inserta este trabajo desde una mirada colectiva y amplia de los conceptos que se exponen. En este libro podrá encontrar las ideas de varios autores y autoras de distintas universidades, con una visión multi, inter y transdisciplinaria. El esfuerzo que se realizó para conjuntar varios términos y analizar su compleja red de interpretaciones, permitirá que este manuscrito pueda ser consultado por estudiantes, personas del ámbito científico-académico, y ciudadanía; porque contiene el estado del arte, la historia del paulatino avance de múltiples conceptos y su vigencia en el contexto actual
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