Browsing by Autor "Gabriel Arellano"

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Amazon tree dominance across forest strata
(Nature Portfolio, 2021) Frederick C. Draper; Flávia R. C. Costa; Gabriel Arellano; Oliver L. Phillips; Álvaro Duque; Manuel J. Macía; Hans ter Steege; Gregory P. Asner; Érika Berenguer; Juliana Schietti
Aportes de nitrógeno y fósforo al suelo a través de la hojarasca en dos agroecosistemas de café (coffea arábica) bajo sombra en los andes venezolanos.
(2015) Gabriel Arellano; Jorge Paolini; E A Hoyos Villegas; Miguel Ángel Gallegos-Robles
During one year period , the contribution of nitrogen (N) and phosphorous (P) to the soil through incorporating dead leaves in decomposition in two coffee agroecosystems (coffee arabiga) located in the sector Vitu, Municipality of Pampan , Trujillo State, was evaluated. In system A, coffee plants were mainly in the shade of trees like Ficus caruca and Inga spp, while system B . consisted in coffee in the shade of trees like Inga spp., Persea Americana and Bixa orellana, among others. The research was carried out in three stages ; a fi el stage in which decomposition of dead leaves was determined by means of the “litter bags” method; and a laboratory stage where concentrations of nitrogen (N) and phosphorous (P) were determinated by means of the Kjedahl and blue molybdenus methods, respectively, the controbutions of these parameters to the organic humus were evaluated too. Concentrations of N and P in system A were 2,10 – 3,00 % of coffee, 1,30 – 2,07 % N of tree leaves and 0,07 – 0,12 % of coffee, respectively. In system B, the contribution were: 2,03 – 2,38 % of coffee, 1,90 – 2,69 % N of tree leaves , and 0,11 – 0,16 % of coffee, 0,07 – 0,15 % of tree leaves. The contribution of tree leaves to the organic humus in system A were: N: 83,16 (Kg/ ha/year) and of N: 104,97 (Kg/ha/year) for system B, respectively. Constributions of P for system A was of 3,61 Kg/ha/year) and of 5,73 (Kg/ha/year) for system B. A light increase of values from N and P in dead leaves was also noticed. These results can be attributed to the fact that system B has different shade trees with respect to system A; however, the concentration of N and P in the organic humus are generally similar. Coffee farming in the shade provides an adequate microclime in humidity and temperature, basic for the development of the plant in not best areas for that kind of farming; this fact confers it a great ecological importance. For comparing these results the SAS statistical pack and the one-way variance analysis were used.
Commonness and rarity determinants of woody plants in different types of tropical forests
(Springer Science+Business Media, 2014) Gabriel Arellano; M. Isabel Loza; J. Sebastián Tello; Manuel J. Macía
Disentangling environmental and spatial processes of community assembly in tropical forests from local to regional scales
(Wiley, 2015) Gabriel Arellano; J. Sebastián Tello; Peter M. Jørgensen; A C.; M. Isabel Loza; Vania Torrez; Manuel J. Macía
Understanding patterns and mechanisms of variation in the compositional structure of communities across spatial scales is one of the fundamental challenges in ecology and biogeography. In this study, we evaluated the effects of spatial extent (i.e. size of study region) on: 1) whether community composition can be better explained by environmental (i.e. niche‐based) or spatial (e.g. dispersal‐based) processes ; and 2) how climate and soils contribute to the influence of environment on plant community composition. We surveyed community composition across a network of 398 forest plots spanning a ∼4000 m elevational gradient in the Madidi region in northwestern Bolivia. Using redundancy analyses and hierarchical variation partitioning, we disentangled the effects of environmental and spatial predictors on species composition, further decomposing the environmental effect between its climatic and soil components. We repeated analyses for 200 sub‐regions ranging in spatial extent from ∼250 to ∼17 500 km 2 . Our analyses show a high degree of idiosyncrasy in results that come from different sub‐regions. Despite this variability, we were able to identify various important patterns in the structure of tropical plant communities in our study system. First, even though sub‐regions varied in size by nearly two orders of magnitude, the total amount of explained variation in community composition was scale independent; at all spatial scales, environment and space accounted for about 25% of the differences in community composition among plots. Second, the measured environmental effect was higher than the spatial effect on average and in the vast majority of sub‐regions. This was true regardless of the spatial extent of analysis. Finally, we found that both climatic and soil variables accounted for significant fractions of variation, but climate was always more important than soils.
Editar la revista en tiempos de crisis
(2019) Gabriel Arellano; A Leylan
Elevational Gradients in β-Diversity Reflect Variation in the Strength of Local Community Assembly Mechanisms across Spatial Scales
(Public Library of Science, 2015) J. Sebastián Tello; Jonathan A. Myers; Manuel J. Macía; A C.; Leslie Cayola; Gabriel Arellano; M. Isabel Loza; Vania Torrez; Maritza Cornejo; Tatiana B. Miranda
Despite long-standing interest in elevational-diversity gradients, little is known about the processes that cause changes in the compositional variation of communities (β-diversity) across elevations. Recent studies have suggested that β-diversity gradients are driven by variation in species pools, rather than by variation in the strength of local community assembly mechanisms such as dispersal limitation, environmental filtering, or local biotic interactions. However, tests of this hypothesis have been limited to very small spatial scales that limit inferences about how the relative importance of assembly mechanisms may change across spatial scales. Here, we test the hypothesis that scale-dependent community assembly mechanisms shape biogeographic β-diversity gradients using one of the most well-characterized elevational gradients of tropical plant diversity. Using an extensive dataset on woody plant distributions along a 4,000-m elevational gradient in the Bolivian Andes, we compared observed patterns of β-diversity to null-model expectations. β-deviations (standardized differences from null values) were used to measure the relative effects of local community assembly mechanisms after removing sampling effects caused by variation in species pools. To test for scale-dependency, we compared elevational gradients at two contrasting spatial scales that differed in the size of local assemblages and regions by at least an order of magnitude. Elevational gradients in β-diversity persisted after accounting for regional variation in species pools. Moreover, the elevational gradient in β-deviations changed with spatial scale. At small scales, local assembly mechanisms were detectable, but variation in species pools accounted for most of the elevational gradient in β-diversity. At large spatial scales, in contrast, local assembly mechanisms were a dominant force driving changes in β-diversity. In contrast to the hypothesis that variation in species pools alone drives β-diversity gradients, we show that local community assembly mechanisms contribute strongly to systematic changes in β-diversity across elevations. We conclude that scale-dependent variation in community assembly mechanisms underlies these iconic gradients in global biodiversity.
Elevational range sizes of woody plants increase with climate variability in the Tropical Andes
(Wiley, 2023) Flavia Montaño‐Centellas; A C.; Leslie Cayola; Manuel J. Macía; Gabriel Arellano; M. Isabel Loza; Beatriz Nieto‐Ariza; J. Sebastián Tello
Abstract Aim The climate variability hypothesis proposes that species subjected to wide variation in climatic conditions will evolve wider niches, resulting in larger distributions. We test this hypothesis in tropical plants across a broad elevational gradient; specifically, we use a species‐level approach to evaluate whether elevational range sizes are explained by the levels of thermal variability experienced by species. Location Central Andes. Time Period Present day. Taxon Woody plants. Methods Combining data from 479 forest plots, we determined the elevational distributions of nearly 2300 species along an elevational gradient (~209–3800 m). For each species, we calculated the maximum annual variation in temperature experienced across its elevational distribution. We used phylogenetic generalized least square models to evaluate the effect of thermal variability on range size. Our models included additional covariates that might affect range size: body size, local abundance, mean temperature and total precipitation. We also considered interactions between thermal variability and mean temperature or precipitation. To account for geometric constraints, we repeated our analyses with a standardized measure of range size, calculated by comparing observed range sizes with values obtained from a null model. Results Our results supported the main prediction of the climate variability hypothesis. Thermal variability had a strong positive effect on the range size, with species exposed to higher thermal variability having broader elevational distributions. Body size and local abundance also had positive, yet weak effects, on elevational range size. Furthermore, there was a strong positive interaction between thermal variability and mean annual temperature. Main Conclusions Thermal variability had an overriding importance in driving elevational range sizes of woody plants in the Central Andes. Moreover, the relationship between thermal variability and range size might be even stronger in warmer regions, underlining the potential vulnerability of tropical montane floras to the effects of global warming.
Elevational Range Sizes of Woody plants Increase with Climate Variability in the Tropical Andes
(2023) Flavia Montaño‐Centellas; Alfredo F. Fuentes; Leslie Cayola; Manuel J. Macía; Gabriel Arellano; M. Isabel Loza; Beatriz Nieto‐Ariza; J. Sebastián Tello
Abstract Aim The climate variability hypothesis proposes that species subjected to wide variation in climatic conditions will evolve wider niches, resulting in larger distributions. We test this hypothesis in tropical plants across a broad elevational gradient; specifically, we use a species-level approach to evaluate whether elevational range sizes are explained by the levels of thermal variability experienced by species. Location Central Andes Time period Present day Major taxa studied Woody plants Methods Combining data from 479 forest plots, we determined the elevational distributions of nearly 2300 species along an elevational gradient (∼209 – 3800 m). For each species, we calculated the maximum annual variation in temperature experienced across its elevational distribution. We used phylogenetic generalized least square models to evaluate the effect of thermal variability on range size. Our models included additional covariates that might affect range size: body size, local abundance, mean temperature and total precipitation. We also considered interactions between thermal variability and mean temperature or precipitation. To account for geometric constraints, we repeated our analyses with a standardized measure of range size, calculated by comparing observed range sizes with values obtained from a null model. Results Our results supported the main prediction of the climate variability hypothesis. Thermal variability had a strong positive effect on the range size, with species exposed to higher thermal variability having broader elevational distributions. Body size and local abundance also had positive, yet weak effects, on elevational range size. Furthermore, there was a strong positive interaction between thermal variability and mean annual temperature. Main conclusions Thermal variability had an overriding importance in driving elevational range sizes of woody plants in the Central Andes. Moreover, the relationship between thermal variability and range size might be even stronger in warmer regions, underlining the potential vulnerability of tropical montane floras to the effects of global warming.
Insights on biodiversity drivers to predict species richness in tropical forests at the local scale
(Elsevier BV, 2022) Rubén G. Mateo; Gabriel Arellano; Virgilio Gómez‐Rubio; J. Sebastián Tello; Alfredo F. Fuentes; Leslie Cayola; M. Isabel Loza; Victoria Cala Rivero; Manuel J. Macía
Disentangling the relative importance of different biodiversity drivers (i.e., climate, edaphic, historical factors, or human impact) to predict plant species richness at the local scale is one of the most important challenges in ecology. Biodiversity modelling is a key tool for the integration of these drivers and the predictions generated are essential, for example, for climate change forecast and conservation planning. However, the reliability of biodiversity models at the local scale remains poorly understood, especially in tropical species-rich areas, where they are required. We inventoried all woody plants with stems ≥ 2.5 cm in 397 plots across the Andes-Amazon gradient. We generated and mapped 19 uncorrelated biodiversity drivers at 90 m resolution, grouped into four categories: microclimatic, microtopographic, anthropic, and edaphic. In order to evaluate the importance of the different categories, we grouped biodiversity drivers into four different clusters by categories. For each of the four clusters of biodiversity drivers, we modelled the observed species richness using two statistical techniques (random forest and Bayesian inference) and two modelling procedures (including or excluding a spatial component). All the biodiversity models produced were evaluated by cross-validation. Species richness was accurately predicted by random forest (Spearman correlation up to 0.85 and explained variance up to 67%). The results suggest that precipitation and temperature are important driving forces of species richness in the region. Nonetheless, a spatial component should be considered to properly predict biodiversity. This could reflect macroevolutionary underlying forces not considered here, such as colonization time, dispersal capacities, or speciation rates. However, the proposed biodiversity modelling approach can predict accurately species richness at the local scale and detailed resolution (90 m) in tropical areas, something that previous works had found extremely challenging. The innovative methodology presented here could be employed in other areas with conservation needs.
Madidi Project Full Dataset
(European Organization for Nuclear Research, 2020) J. Sebastián Tello; Manuel J. Macía; Gabriel Arellano; Leslie Cayola; Alfredo F. Fuentes
This item contains version 3.0 of the Madidi Project's full dataset. The zip file contains (1) raw data, which was downloaded from Tropicos (www.tropicos.org) on February 3, 2020; (2) R scripts used to modify, correct, and clean the raw data; (3) clean data that are the output of the R scripts, and which are the point of departure for most uses of the Madidi Dataset; (4) additional post-cleaning scripts that obtain some additional but non-essential information from the clean data; and (5) a miscellaneous collection of additional non-essential information and figures. This item also includes the Data Use Policy for this dataset. The core dataset of the Madidi Project consists of a network of ~500 forest plots distributed in and around the Madidi National Park in Bolivia. This network contains 50 permanently marked large plots (1-ha), as well as ~450 temporary small plots (0.1-ha). Within the large plots, all woody individuals with a dbh ≥10 cm have been mapped, tagged, measured, and identified. Some of these plots have also been re-visited and information on mortality, recruitment, and growth exists. Within the small plots, all woody individuals with a dbh ≥2.5 cm have been measured and identified. Each plot has some edaphic and topographic information, and some large plots have information on various plant functional traits. The Madidi Project is a collaborative research effort to document and study plant biodiversity in the Amazonia and Tropical Andes of northwestern Bolivia. The project is currently lead by the Missouri Botanical Garden (MBG), in collaboration with the Herbario Nacional de Bolivia. The management of the project is at MBG, where J. Sebastian Tello (sebastian.tello@mobot.org) is the scientific director and Olga Martha Montiel (olgamartha.montiel@mobot.org) is the administrative director. The directors oversee the activities of a research team based in Bolivia. MBG works in collaboration with other data contributors (currently: Manuel J. Macía [manuel.macia@uam.es], and Gabriel Arellano [gabriel.arellano.torres@gmail.com]), with a representative from the Herbario Nacional de Bolivia (LPB; Carla Maldonado [carla.maldonado1@gmail.com]), as well as with other close associated researchers from various institutions. For more information regarding the organization and objectives of the Madidi Project, you can visit the project’s website (www.madidiproject.weebly.com).
Madidi Project Full Dataset
(European Organization for Nuclear Research, 2018) J. Sebastián Tello; Manuel J. Macía; Gabriel Arellano; Leslie Cayola; Alfredo F. Fuentes
This item contains version 2.1 of the Madidi Project's full dataset. The zip file contains (1) raw data, which was downloaded from Tropicos (www.tropicos.org) on December 6, 2018; (2) R scripts used to modify, correct, and clean the raw data; (3) clean data that are the output of the R scripts, and which are the point of departure for most uses of the Madidi Dataset; (4) additional post-cleaning scripts that obtain some additional but non-essential information from the clean data. This item also includes the Data Use Policy for this dataset. The core dataset of the Madidi Project consists of a network of ~500 forest plots distributed in and around the Madidi National Park in Bolivia. This network contains 50 permanently marked large plots (1-ha), as well as ~450 temporary small plots (0.1-ha). Within the large plots, all woody individuals with a dbh ≥10 cm have been mapped, tagged, measured, and identified. Some of these plots have also been re-visited and information on mortality, recruitment, and growth exists. Within the small plots, all woody individuals with a dbh ≥2.5 cm have been measured and identified. Each plot has some edaphic and topographic information, and some large plots have information on various plant functional traits. The Madidi Project is a collaborative research effort to document and study plant biodiversity in the Amazonia and Tropical Andes of northwestern Bolivia. The project is currently lead by the Missouri Botanical Garden (MBG), in collaboration with the Herbario Nacional de Bolivia. The management of the project is at MBG, where J. Sebastian Tello (sebastian.tello@mobot.org) is the scientific director and Olga Martha Montiel (olgamartha.montiel@mobot.org) is the administrative director. The directors oversee the activities of a research team based in Bolivia. MBG works in collaboration with other data contributors (currently: Manuel J. Macía [manuel.macia@uam.es], and Gabriel Arellano [gabriel.arellano.torres@gmail.com]), with a representative from the Herbario Nacional de Bolivia (LPB; Carla Maldonado [carla.maldonado1@gmail.com]), as well as with other close associated researchers from various institutions. For more information regarding the organization and objectives of the Madidi Project, you can visit the project’s website (www.madidiproject.weebly.com).
Madidi Project Full Dataset
(European Organization for Nuclear Research, 2020) J. Sebastián Tello; Manuel J. Macía; Gabriel Arellano; Beatriz Nieto‐Ariza; Leslie Cayola; Alfredo F. Fuentes
This item contains version 4.0 of the Madidi Project's full dataset. The zip file contains (1) raw data, which was downloaded from Tropicos (www.tropicos.org) on August 18, 2020; (2) R scripts used to modify, correct, and clean the raw data; (3) clean data that are the output of the R scripts, and which are the point of departure for most uses of the Madidi Dataset; (4) additional post-cleaning scripts that obtain some additional but non-essential information from the clean data (e.g. by extracting environmental data from rasters); and (5) a miscellaneous collection of additional non-essential information and figures. This item also includes the Data Use Policy for this dataset. The core dataset of the Madidi Project consists of a network of ~500 forest plots distributed in and around the Madidi National Park in Bolivia. This network contains 50 permanently marked large plots (1-ha), as well as >450 temporary small plots (0.1-ha). Within the large plots, all woody individuals with a dbh ≥10 cm have been mapped, tagged, measured, and identified. Some of these plots have also been re-visited and information on mortality, recruitment, and growth exists. Within the small plots, all woody individuals with a dbh ≥2.5 cm have been measured and identified. Each plot has some edaphic and topographic information, and some large plots have information on various plant functional traits. The Madidi Project is a collaborative research effort to document and study plant biodiversity in the Amazonia and Tropical Andes of northwestern Bolivia. The project is currently lead by the Missouri Botanical Garden (MBG), in collaboration with the Herbario Nacional de Bolivia. The management of the project is at MBG, where J. Sebastian Tello (sebastian.tello@mobot.org) is the scientific director and Olga Martha Montiel (olgamartha.montiel@mobot.org) is the administrative director. The directors oversee the activities of a research team based in Bolivia. MBG works in collaboration with other data contributors (currently: Manuel J. Macía [manuel.macia@uam.es], Gabriel Arellano [gabriel.arellano.torres@gmail.com] and Beatriz Nieto [sonneratia@gmail.com]), with a representative from the Herbario Nacional de Bolivia (LPB; Carla Maldonado [carla.maldonado1@gmail.com]), as well as with other close associated researchers from various institutions. For more information regarding the organization and objectives of the Madidi Project, you can visit the project’s website (www.madidiproject.weebly.com).
Madidi Project Full Dataset
(European Organization for Nuclear Research, 2019) J. Sebastián Tello; Manuel J. Macía; Gabriel Arellano; Leslie Cayola; Alfredo F. Fuentes
This item contains version 2.2 of the Madidi Project's full dataset. The zip file contains (1) raw data, which was downloaded from Tropicos (www.tropicos.org) on October 19, 2019; (2) R scripts used to modify, correct, and clean the raw data; (3) clean data that are the output of the R scripts, and which are the point of departure for most uses of the Madidi Dataset; (4) additional post-cleaning scripts that obtain some additional but non-essential information from the clean data; and (5) a miscellaneous collection of additional non-essential information and figures. This item also includes the Data Use Policy for this dataset. The core dataset of the Madidi Project consists of a network of ~500 forest plots distributed in and around the Madidi National Park in Bolivia. This network contains 50 permanently marked large plots (1-ha), as well as ~450 temporary small plots (0.1-ha). Within the large plots, all woody individuals with a dbh ≥10 cm have been mapped, tagged, measured, and identified. Some of these plots have also been re-visited and information on mortality, recruitment, and growth exists. Within the small plots, all woody individuals with a dbh ≥2.5 cm have been measured and identified. Each plot has some edaphic and topographic information, and some large plots have information on various plant functional traits. The Madidi Project is a collaborative research effort to document and study plant biodiversity in the Amazonia and Tropical Andes of northwestern Bolivia. The project is currently lead by the Missouri Botanical Garden (MBG), in collaboration with the Herbario Nacional de Bolivia. The management of the project is at MBG, where J. Sebastian Tello (sebastian.tello@mobot.org) is the scientific director and Olga Martha Montiel (olgamartha.montiel@mobot.org) is the administrative director. The directors oversee the activities of a research team based in Bolivia. MBG works in collaboration with other data contributors (currently: Manuel J. Macía [manuel.macia@uam.es], and Gabriel Arellano [gabriel.arellano.torres@gmail.com]), with a representative from the Herbario Nacional de Bolivia (LPB; Carla Maldonado [carla.maldonado1@gmail.com]), as well as with other close associated researchers from various institutions. For more information regarding the organization and objectives of the Madidi Project, you can visit the project’s website (www.madidiproject.weebly.com).
Madidi Project Full Dataset
(2020) J. Sebastián Tello; Manuel J. Macía; Gabriel Arellano; Leslie Cayola; Beatriz Nieto‐Ariza; Alfredo F. Fuentes
This item contains version 4.1 of the Madidi Project's full dataset. The zip file contains (1) raw data, which was downloaded from Tropicos (www.tropicos.org) on September 7, 2020; (2) R scripts used to modify, correct, and clean the raw data; (3) clean data that are the output of the R scripts, and which are the point of departure for most uses of the Madidi Dataset; (4) additional post-cleaning scripts that obtain some additional but non-essential information from the clean data (e.g. by extracting environmental data from rasters); and (5) a miscellaneous collection of additional non-essential information and figures. This item also includes the Data Use Policy for this dataset. The core dataset of the Madidi Project consists of a network of ~500 forest plots distributed in and around the Madidi National Park in Bolivia. This network contains 50 permanently marked large plots (1-ha), as well as >450 temporary small plots (0.1-ha). Within the large plots, all woody individuals with a dbh ≥10 cm have been mapped, tagged, measured, and identified. Some of these plots have also been re-visited and information on mortality, recruitment, and growth exists. Within the small plots, all woody individuals with a dbh ≥2.5 cm have been measured and identified. Each plot has some edaphic and topographic information, and some large plots have information on various plant functional traits. The Madidi Project is a collaborative research effort to document and study plant biodiversity in the Amazonia and Tropical Andes of northwestern Bolivia. The project is currently lead by the Missouri Botanical Garden (MBG), in collaboration with the Herbario Nacional de Bolivia. The management of the project is at MBG, where J. Sebastian Tello (sebastian.tello@mobot.org) is the scientific director and Olga Martha Montiel (olgamartha.montiel@mobot.org) is the administrative director. The directors oversee the activities of a research team based in Bolivia. MBG works in collaboration with other data contributors (currently: Manuel J. Macía [manuel.macia@uam.es], Gabriel Arellano [gabriel.arellano.torres@gmail.com] and Beatriz Nieto [sonneratia@gmail.com]), with a representative from the Herbario Nacional de Bolivia (LPB; Carla Maldonado [carla.maldonado1@gmail.com]), as well as with other close associated researchers from various institutions. For more information regarding the organization and objectives of the Madidi Project, you can visit the project’s website (www.madidiproject.weebly.com).
Madidi Project Full Dataset
(European Organization for Nuclear Research, 2018) J. Sebastián Tello; Manuel J. Macía; Gabriel Arellano; Leslie Cayola; Alfredo F. Fuentes
This item contains version 2.0 of the Madidi Project's full dataset. The zip file contains: (1) raw data, which was downloaded from Tropicos (www.tropicos.org) on June 11, 2018; (2) R scripts used to modify, correct and clean the raw data; (3) clean data that are the output of the R scripts, and which are the point of departure for most uses of the Madidi Dataset; (4) additional post-cleaning scripts that obtain some additional but non-essential information from the clean data. This item also includes the Data Use Policy for this dataset. The core dataset of the Madidi Project consists of a network of ~500 forest plots distributed in and around the Madidi National Park in Bolivia. This network contains 50 permanently marked large plots (1-ha), as well as ~450 temporary small plots (0.1-ha). Within the large plots, all woody individuals with a dbh ≥10 cm have been mapped, tagged, measured, and identified. Some of these plots have also been re-visited and information on mortality, recruitment and growth exists. Within the small plots, all woody individuals with a dbh ≥2.5 cm have been measured and identified. Each plot has some edaphic and topographic information, and some large plots have information on various plant functional traits. The Madidi Project is a collaborative research effort to document and study plant biodiversity in the Amazonia and Tropical Andes of northwestern Bolivia. The project is currently lead by the Missouri Botanical Garden (MBG), in collaboration with the Herbario Nacional de Bolivia. The management of the project is at MBG, where J. Sebastian Tello (sebastian.tello@mobot.org) is the scientific director and Olga Martha Montiel (olgamartha.montiel@mobot.org) is the administrative director. The directors oversee the activities of a research team based in Bolivia. MBG works in collaboration with other data contributors (currently: Manuel J. Macía [manuel.macia@uam.es], and Gabriel Arellano [gabriel.arellano.torres@gmail.com]), with a representative from the Herbario Nacional de Bolivia (LPB; Carla Maldonado [carla.maldonado1@gmail.com]), as well as with other close associated researchers from various institutions. For more information regarding the organization and objectives of the Madidi Project, you can visit the project’s website (www.madidiproject.weebly.com).
Madidi Project Full Dataset
(European Organization for Nuclear Research, 2021) J. Sebastián Tello; Manuel J. Macía; Gabriel Arellano; Beatriz Nieto‐Ariza; Leslie Cayola; Alfredo F. Fuentes
This item contains version 5.0 of the Madidi Project's full dataset. The zip file contains (1) raw data, which was downloaded from Tropicos (www.tropicos.org) on August 18, 2020; (2) R scripts used to modify, correct, and clean the raw data; (3) clean data that are the output of the R scripts, and which are the point of departure for most uses of the Madidi Dataset; (4) post-cleaning scripts that obtain additional but non-essential information from the clean data (e.g. by extracting environmental data from rasters); and (5) a miscellaneous collection of additional non-essential information and figures. This item also includes the Data Use Policy for this dataset. The core dataset of the Madidi Project consists of a network of ~500 forest plots distributed in and around the Madidi National Park in Bolivia. This network contains 50 permanently marked large plots (1-ha), as well as >450 temporary small plots (0.1-ha). Within the large plots, all woody individuals with a dbh ≥10 cm have been mapped, tagged, measured, and identified. Some of these plots have also been re-visited and information on mortality, recruitment, and growth exists. Within the small plots, all woody individuals with a dbh ≥2.5 cm have been measured and identified. Each plot has some edaphic and topographic information, and some large plots have information on various plant functional traits. The Madidi Project is a collaborative research effort to document and study plant biodiversity in the Amazonia and Tropical Andes of northwestern Bolivia. The project is currently lead by the Missouri Botanical Garden (MBG), in collaboration with the Herbario Nacional de Bolivia. The management of the project is at MBG, where J. Sebastian Tello (sebastian.tello@mobot.org) is the scientific director. The director oversees the activities of a research team based in Bolivia. MBG works in collaboration with other data contributors (currently: Manuel J. Macía [manuel.macia@uam.es], Gabriel Arellano [gabriel.arellano.torres@gmail.com] and Beatriz Nieto [sonneratia@gmail.com]), with a representative from the Herbario Nacional de Bolivia (LPB; Carla Maldonado [carla.maldonado1@gmail.com]), as well as with other close associated researchers from various institutions. For more information regarding the organization and objectives of the Madidi Project, you can visit the project’s website (www.madidiproject.weebly.com).
Madidi Project Full Dataset
(2021) J. Sebastián Tello; Manuel J. Macía; Gabriel Arellano; Beatriz Nieto‐Ariza; Leslie Cayola; Alfredo F. Fuentes
This item contains version 5.0 of the Madidi Project's full dataset. The zip file contains (1) raw data, which was downloaded from Tropicos (www.tropicos.org) on August 18, 2020; (2) R scripts used to modify, correct, and clean the raw data; (3) clean data that are the output of the R scripts, and which are the point of departure for most uses of the Madidi Dataset; (4) post-cleaning scripts that obtain additional but non-essential information from the clean data (e.g. by extracting environmental data from rasters); and (5) a miscellaneous collection of additional non-essential information and figures. This item also includes the Data Use Policy for this dataset. The core dataset of the Madidi Project consists of a network of ~500 forest plots distributed in and around the Madidi National Park in Bolivia. This network contains 50 permanently marked large plots (1-ha), as well as >450 temporary small plots (0.1-ha). Within the large plots, all woody individuals with a dbh ≥10 cm have been mapped, tagged, measured, and identified. Some of these plots have also been re-visited and information on mortality, recruitment, and growth exists. Within the small plots, all woody individuals with a dbh ≥2.5 cm have been measured and identified. Each plot has some edaphic and topographic information, and some large plots have information on various plant functional traits. The Madidi Project is a collaborative research effort to document and study plant biodiversity in the Amazonia and Tropical Andes of northwestern Bolivia. The project is currently lead by the Missouri Botanical Garden (MBG), in collaboration with the Herbario Nacional de Bolivia. The management of the project is at MBG, where J. Sebastian Tello (sebastian.tello@mobot.org) is the scientific director. The director oversees the activities of a research team based in Bolivia. MBG works in collaboration with other data contributors (currently: Manuel J. Macía [manuel.macia@uam.es], Gabriel Arellano [gabriel.arellano.torres@gmail.com] and Beatriz Nieto [sonneratia@gmail.com]), with a representative from the Herbario Nacional de Bolivia (LPB; Carla Maldonado [carla.maldonado1@gmail.com]), as well as with other close associated researchers from various institutions. For more information regarding the organization and objectives of the Madidi Project, you can visit the project’s website (www.madidiproject.weebly.com).
Mechanisms of community assembly explaining beta‐diversity patterns across biogeographic regions
(Wiley, 2021) Miguel Muñoz Mazón; J. Sebastián Tello; Manuel J. Macía; Jonathan A. Myers; Peter M. Jørgensen; Victoria Cala Rivero; Alfredo F. Fuentes; Vania Torrez; Gabriel Arellano
Abstract Aim We examined tree beta diversity in four biogeographical regions with contrasting environmental conditions, latitude, and diversity. We tested: (a) the influence of the species pool on beta diversity; (b) the relative contribution of niche‐based and dispersal‐based assembly to beta diversity; and (c) differences in the importance of these two assembly mechanisms in regions with differing productivity and species richness. Location Lowland and montane tropical forests in the Madidi region (Bolivia), lowland temperate forests in the Ozarks (USA), and montane temperate forests in the Cantabrian Mountains (Spain). Methods We surveyed woody plants with a diameter ≥2.5 cm following a standardized protocol in 236 0.1‐ha forest plots in four different biogeographical regions. We estimated the species pool at each region and used it to recreate null communities determined entirely by the species pool. Observed patterns of beta diversity smaller or greater than the null‐expected patterns of beta diversity implies the presence of local assembly mechanisms beyond the influence of the species pool. We used variation‐partitioning analyses to compare the contribution of niche‐based and dispersal‐based assembly to patterns of observed beta diversity and their deviations from null models among the four regions. Results (a) Differences in species pools alone did not explain observed differences in beta diversity among biogeographic regions. (b) In 3/4 regions, the environment explained more of the variation in beta diversity than spatial variables. (c) Spatial variables explained more of the beta diversity in more diverse and more productive regions with more rare species (tropical and lower‐elevation regions) compared to less diverse and less productive regions (temperate and higher‐elevation regions). (d) Greater alpha or gamma diversity did not result in higher beta diversity or stronger correlations with the environment. Conclusion Overall, the observed differences in beta diversity are better explained by differences in community assembly mechanism than by biogeographical processes that shaped the species pool.
Oligarchic patterns in tropical forests: role of the spatial extent, environmental heterogeneity and diversity
(Wiley, 2015) Gabriel Arellano; Peter M. Jørgensen; A C.; M. Isabel Loza; Vania Torrez; Manuel J. Macía
Abstract Aim Oligarchic patterns can vary from weak (i.e. little difference between rare and common species) to strong (i.e. a set of dominant species is immediately evident). Our aim was to understand the relationships between the strength of the oligarchic patterns, diversities (alpha, beta and gamma), and five potential causes (elevational variability, soil heterogeneity, elevation, soil conditions and geographical extent). Location The Amazon–Andes transition in the Madidi region (Bolivia). Methods We established 398 plots of 0.1 ha each, containing 121,183 individual woody plants belonging to 2390 species. Then we defined 500 sub‐regions (= unique overlapping subsets of 50 plots from the pool of 398 plots) so they varied in extent from 220 to 17,700 km 2 within the study area. We employed two independent path analyses to relate environmental characteristics and geographical extent of sub‐regions to (1) oligarchic strength and (2) alpha, beta and gamma diversities. We used generalized linear models to relate diversities to different measures of oligarchic strength. Results Oligarchies at larger extents were weaker, a trend strongly driven by the pure effect of area and, secondarily, by environmental heterogeneity. Oligarchies at higher elevations were weaker than expected, and oligarchies in acidic and nutrients‐poor soils were not stronger than those in less stressful soils. Trends in oligarchic strength were inversely correlated with those of gamma and beta diversity: weaker oligarchies were found in species‐rich and heterogeneous communities. Main conclusions Environmental heterogeneity and low landscape connectivity limit the strength of the oligarchic pattern. Although diversities (particularly beta diversity) and oligarchic strength are closely related, they are somewhat differently driven by external factors. In particular, oligarchic strength is more sensitive to spatial extent and less sensitive to environmental heterogeneity than beta diversity. Finally, the study of oligarchic patterns should consider a priori expectations based on species richness and turnover.
Phylogenetic patterns of rarity in a regional species pool of tropical woody plants
(Wiley, 2017) M. Isabel Loza; Iván Jiménez; Peter M. Jørgensen; Gabriel Arellano; Manuel J. Macía; Vania Torrez; Robert E. Ricklefs
Abstract Aim Rarity, which is believed to influence extinction risk, can be defined in terms of local abundance, geographical range size and habitat breadth. Phylogenetic patterns in these attributes provide insight into the extent to which rarity and extinction risk are conserved during evolution and the potential for species‐level heritability. We evaluated phylogenetic signal (i.e., related species resembling each other more than species drawn at random) and evolutionary conservatism (similarity among related species exceeding that expected from a Brownian model of evolution) in three axes of rarity (local abundance, geographical range size and habitat breadth) among species in a regional pool of tropical woody plants. Location The Madidi region in Bolivia. Time period 2001–2010. Major taxa studied Lignophyta clade. Methods We used a network of 48 1‐ha forest plots and 442 0.1‐ha forest plots to measure local abundance and habitat breadth of 1,700+ woody plant species (from 100+ plant families). We estimated geographical range size from occurrence records of individual species across the Neotropics. We characterized overall phylogenetic patterns of rarity using Blomberg's K and applied variance partitioning among taxonomic levels, as well as disparity analysis, to describe patterns of trait distribution at different depths in the phylogeny. Results We found phylogenetic signal, but not evolutionary conservatism, in the three axes of rarity. The variance in rarity among supra‐specific taxa, particularly families and genera, exceeded that calculated from random draws of species from the Madidi region. Phylogenetic signal, estimated by the proportion of variance among supra‐specific taxonomic levels, varied between 23 and 36% for local abundance and geographical range size, and between 9 and 10% for habitat breadth. Main conclusions The regional pool of woody plant species in Madidi exhibits phylogenetic signal in rarity that is consistent with biologically significant species‐level heritability.