Abstract Introduction: Melina (Gmelina arborea) is a tree species of great interest for its wood and medicinal properties. In Costa Rica, there are genetically superior clones that are propagated without knowledge of the ontogenic and physiological age of the materials. Objective: To evaluate how age influences the content of phenols and lignins in leaves, petioles, stems, and roots of melina plants. Methods: The total phenolic and lignins contents were determined using Folin-Ciocalteu colorimetric method and alkaline extraction method, respectively. Plants of five different ages were chosen for the investigation (in vitro plants “year 0” and trees of a year and a half, four, seven and 20 years). Sampling was done in March and April 2021. Results: All parts of the plant analyzed contain phenolic compounds and lignins, regardless of their age. There was no positive correlation between age and phenol and lignin content for any development condition, since the highest values were not obtained in the oldest trees. Leaf extracts from in vitro plants and seven-year-old trees showed, respectively, the highest phenol and lignin contents for all conditions (P < 0.05). The lowest average values of phenolic compounds for all conditions were obtained in four-year-old trees. Regarding lignins, the lowest content occurred in the oldest roots, although the trend was not maintained for the rest of the plant parts. Conclusions: This study provides the first results of the content of phenolic compounds and lignins present in different tissues of a forest species of different ages. Therefore, they are the first reference values about the biochemical commitment for phenolic synthesis according to the age and the specific developmental stage of a woody plant.

Resumen Introducción: La melina (Gmelina arborea), es una especie de gran interés por su madera y propiedades medicinales. En Costa Rica, existen clones genéticamente superiores que se propagan sin el conocimiento de la edad ontogénica y fisiológica de los materiales. Objetivo: Evaluar la relación del contenido de fenoles y ligninas en hojas, peciolos, tallos y raíces de plantas con diferentes edades. Métodos: Los contenidos de fenoles y ligninas totales se determinaron mediante el método colorimétrico de Folin-Ciocalteu y el método de extracción alcalina, respectivamente. Para la investigación se eligieron plantas in vitro “año cero” y árboles de año y medio, cuatro, siete y 20 años. El muestreo se realizó en marzo y abril del 2021. Resultados: Se demostró que todas las partes de la planta analizadas contienen compuestos fenólicos y ligninas, independientemente de su edad. No hubo una correlación positiva entre la edad con el contenido de fenoles y ligninas para ninguna condición de desarrollo, pues los valores más altos no se obtuvieron en los árboles más longevos. Los extractos de hojas de las plantas in vitro y los árboles de siete años mostraron, respectivamente, los contenidos más altos de fenoles y ligninas para todas las condiciones (P < 0.05). Los valores promedio más bajos de compuestos fenólicos para todas las condiciones se obtuvieron en los árboles de cuatro años. Respecto a las ligninas, el contenido más bajo se presentó en las raíces más longevas, aunque la tendencia no se mantuvo para el resto de las partes de la planta. Conclusiones: La investigación muestra los primeros resultados del contenido de compuestos fenólicos y ligninas presentes en diferentes tejidos de una especie forestal de edades diferentes. Por lo tanto, son los primeros valores de referencia acerca del compromiso bioquímico para la síntesis fenólica según la edad y el estado de desarrollo específico de una planta leñosa.

Abstract Introduction: The Wood Thrush is a migratory bird that has experienced dramatic declines in its populations in recent decades. This species overwinters in forest fragments with intermediate levels of habitat modification in Central America. However, more studies detailing the use of remnant forests through time are needed to elucidate the threats this species faces in the wintering grounds. Objective: To understand the effects of environmental and forest structure variables on the occupancy of Wood Thrush in Northern Costa Rica. Methods: The study area was the Área de Conservación Guanacaste (ACG), located in Northern Costa Rica, in December 2016, and during the 2018-2019 migration season. We estimated Wood Thrush occupancy and detection probability in four locations of ACG (dry forest, cloud forest, and two locations in the wet forest) using single-season occupancy models. We also estimated Wood Thrush occupancy and probability of persistence in different months in three vegetation types (open area, secondary forest, and old-growth forest) in the wet forest of ACG using a multi-season occupancy model approach. Results: Wood Thrush occupancy was best described by precipitation in the four locations of the ACG; the probability of occupancy increased with precipitation. The average occupancy of Wood Thrushes varied with vegetation type: open area with shrubs and forest edge (0.69 ± 0.09), secondary forest (0.46 ± 0.1), and old-growth forest (0.61 ± 0.1). Wood Thrush probability of persistence responded partially to changes in precipitation, with an unexpected increase in persistence when the rainfall continued decreasing in the season. Conclusion: Wood Thrush occupancy was best predicted by changes in precipitation considering a larger spatial scale. Its probability of persistence partially varied with precipitation. An increase in persistence closer to Spring migration might be explained by the start of the breeding season of resident birds, potentially reducing territorial conflicts and conserving energy before migration. The long-term protection of wet forests in Northern Costa Rica is of paramount importance for the conservation of Wood Thrushes in their wintering grounds.

Resumen Introducción: El Zorzal del Bosque es un ave migratoria que ha experimentado caídas dramáticas en sus poblaciones en las últimas décadas. Esta especie pasa el invierno en fragmentos de bosque con niveles intermedios de modificación de hábitat en Centroamérica. Sin embargo, se necesitan más estudios que detallen el uso de los bosques remanentes a lo largo del tiempo para dilucidar las amenazas que enfrenta esta especie en las zonas de invernada. Objetivo: Comprender los efectos de variables ambientales y de estructura del bosque en la ocurrencia del Zorzal del Bosque en el Norte de Costa Rica. Métodos: El área de estudio fue el Área de Conservación Guanacaste (ACG), ubicada en el Norte de Costa Rica, en diciembre de 2016, y en la temporada migratoria 2018-2019. Estimamos la ocurrencia y la probabilidad de detección del Zorzal del Bosque en cuatro ubicaciones de ACG (bosque seco, bosque nuboso y dos ubicaciones en el bosque húmedo) utilizando modelos de ocurrencia de una sola temporada. También estimamos la ocurrencia del Zorzal del Bosque y la probabilidad de persistencia en diferentes meses en tres tipos de vegetación (área abierta, bosque secundario y bosque primario) en el bosque húmedo de ACG utilizando un enfoque de modelo de ocurrencia multi-estacional. Resultados: La ocurrencia del Zorzal del Bosque estuvo mejor descrita por la precipitación en las cuatro localidades del ACG; la probabilidad de ocurrencia aumentó con las precipitaciones. La ocurrencia media de zorzales varió con el tipo de vegetación: área abierta con arbustos y borde de bosque (0.69 ± 0.09), bosque secundario (0.46 ± 0.1) y bosque primario (0.61 ± 0.1). La probabilidad de persistencia del zorzal respondió parcialmente a cambios en la precipitación, con un aumento inesperado en la persistencia cuando las precipitaciones continuaron disminuyendo en la temporada. Conclusión: La ocurrecia del Zorzal del Bosque varió con la precipitación considerando una escala espacial mayor. Su probabilidad de persistencia varió parcialmente con la precipitación. Un aumento en la persistencia más cerca de la migración de primavera podría explicarse por el inicio de la temporada de reproducción de las aves residentes, lo que podría reducir los conflictos territoriales y conservar energía antes de la migración. La protección a largo plazo de los bosques húmedos en el norte de Costa Rica es de suma importancia para la conservación de los Zorzales del Bosque en sus zonas de invernada.

Abstract Background: Although the loss of Melipona beecheii colonies in meliponaries suggests insufficient availability of melliferous blooming plants, there is limited knowledge about the diversity and conditions of the surrounding vegetation. Question: What is the diversity, structure, and composition of the melliferous and non-melliferous vegetation surrounding meliponaries, and how does it affect the availability of food sources for bees? Study site and dates: The vegetation surrounding nine meliponaries, three in each political state of the Yucatán Peninsula encompassing the main vegetation types, was studied in 2022 and 2023. Methods: Four 150-meter-long transects with the point-centered quadrants method were traced in each meliponary to estimate plant species composition, the availability of melliferous and blooming plants (IVI), diversity parameters (Hill-numbers), tree density, and diameter per strata. Results: 312 taxa, 250 genera, and 73 plant families were recorded. In five meliponaries, blooming melliferous plants accounted for less than 9 % of the IVI, with one meliponary having no blooming species. The highest diversity was found in a meliponary surrounded by semi-evergreen forest. The high stratum had a mean tree height of 5.5 (SD ± 2.9) meters and 3,390 (SD ± 2,702) trees/hectare across vegetation types. The tree diameter was lowest in meliponaries located in the semi-deciduous forest. Conclusions: The meliponaries are surrounded by young secondary vegetation with high density of small trees and predominance of the low stratum. We found a similar vegetation diversity among meliponaries and scarce blooming melliferous plants. Human activity seems to impact plant diversity and food availability for M. beecheii.

Resumen Antecedentes: Aunque la pérdida de colonias de Melipona beecheii en meliponarios sugiere insuficientes plantas melíferas en floración, existe conocimiento limitado sobre la diversidad y condiciones de la vegetación circundante. Pregunta: ¿Cuál es la diversidad, estructura y composición de la vegetación melífera y no melífera circundante a los meliponarios y cómo afecta a la disponibilidad de fuentes de alimento para las abejas? Sitio de estudio y fechas: Vegetación circundante de nueve meliponarios, tres por cada estado de la Península de Yucatán, abarcando los principales tipos de vegetación en 2022 y 2023. Métodos: Con cuatro transectos de 150-metros por meliponario y método de cuadrantes centrados en puntos, se estimó composición, disponibilidad de plantas melíferas y con flores (IVI), parámetros de diversidad (números de Hill), densidad y diámetros de árboles. Resultados: 312 taxa, 250 géneros y 73 familias de plantas registradas. En cinco meliponarios, las plantas melíferas floreciendo representaron menos del 9 % del IVI y uno no tuvo especies floreciendo. La mayor diversidad fue en un meliponario rodeado de selva mediana subperennifolia. La altura promedio de árboles en el estrato alto fue 5.5 (DE ± 2,9) metros, con 3,390 (DE ± 2.702) árboles/hectárea en todos los tipos de vegetación. El diámetro de árboles fue menor en meliponarios en selva mediana subcaducifolia. Conclusiones: Los meliponarios están rodeados de vegetación secundaria joven, alta densidad de árboles pequeños, predominio del estrato bajo, características similares y escasas plantas melíferas floreciendo, sugiriendo que, la actividad humana afecta la diversidad vegetal y disponibilidad de alimento para M. beecheii.

Abstract Introduction: Amazonian forests with varying degrees of anthropogenic disturbance in the process of natural regeneration harbour many sympatric primate species. However, studies on their usage by primates are still lacking. Objective: To comprehensively study the spatial and temporal dynamics within the primate community in a regenerating forest within the Manu Biosphere Reserve. Methods: Two sets of historical data from Crees Foundation for Manu were analyzed, comprising records from January 2011 to February 2023 and corresponding to data obtained through incidental data and Terrestrial In-line Transects in three types of forest with different degrees of historical disturbance. Results: Lagothrix lagothricha and Ateles chamek showed a preference for less disturbed forests; Plecturocebus toppini, for more disturbed forests; and the other species did not show a clear preference. Regarding vertical stratification, A. chamek, L. lagothricha and Alouatta sara showed a preference for the upper stratum, P. toppini, Saimiri boliviensis and Sapajus macrocephalus showed a preference for the middle and upper strata and Leontocebus weddelli and Aotus nigriceps, for the middle stratum. According to the temporal activity of each species, seven species (A. chamek, S. macrocephalus, S. boliviensis, P. toppini, L. lagothricha, L. weddelli, and A. sara) were observed during the day, four were similar. Conclusions: The primate community varies according to disturbance gradient due to the preferences of some species. The recorded primates make a differentiated use of the vertical strata and most of them show diurnal activity.

Resumen Introducción: Los bosques amazónicos con diferentes grados de perturbación antrópica en proceso de regeneración natural albergan gran cantidad de especies de primates en simpatría. Sin embargo, aún es carente el estudio de su uso por primates. Objetivos: Estudiar la dinámica espacial y temporal dentro de la comunidad de primates en un bosque en regeneración en la Reserva de Biosfera del Manu. Métodos: Se analizaron dos sets de datos históricos de Crees Foundation for Manu que comprenden registros desde enero 2011 hasta febrero 2023 y corresponden a datos incidentales y transectos lineales terrestres en tres tipos de bosque con diferente grado de perturbación histórica. Resultados: Lagothrix lagothricha y Ateles chamek mostraron preferencia por bosques menos perturbados; Plecturocebus toppini, por bosques más perturbados; y las demás especies no mostraron una preferencia clara. En cuanto a la estratificación vertical, A. chamek, L. lagothricha y Alouatta sara mostraron preferencia por el estrato alto; P. toppini, Saimiri boliviensis y Sapajus macrocephalus mostraron preferencia por los estratos medio y alto, y Leontocebus weddelli y Aotus nigriceps, por el estrato medio. De acuerdo con la frecuencia horaria de cada especie se observó que siete especies (A. chamek, S. macrocephalus, S. boliviensis, P. toppini, L. lagothricha, Leontocebus weddelli y A. sara) fueron observadas durante el día, cuatro fueron similares. Conclusiones: En el estudio, la comunidad de primates cambió en el gradiente de perturbación debido a las preferencias de algunas especies. Los primates registrados hacen un uso diferenciado de los estratos verticales y la mayoría de ellos mostraron períodos de actividad diurnos.

Resumen Antecedentes: Las especies arbóreas pioneras que comúnmente dominan la sucesión secundaria temprana del bosque tropical caducifolio pueden afectar las posibles rutas sucesionales. Mimosa acantholoba var. eurycarpa es una especie muy dominante en el bosque tropical caducifolio de México. Hipótesis: Mimosa acantholoba var. eurycarpa ejerce un efecto inhibitorio sobre la germinación, establecimiento, supervivencia y crecimiento inicial de especies pioneras intolerantes a la sombra, pero facilita estos procesos para especies de bosque maduro tolerantes a la sombra. Especies de estudio: Lonchocarpus torresiorum, Lysiloma divaricatum, Mimosa acantholoba var. eurycarpa y Vachellia farnesiana Sitio y años de estudio: Nizanda, Oaxaca, México, 2020-2021. Métodos: En 12 parcelas de sucesión secundaria temprana, aplicamos tres niveles de remoción de copa de M. acantholoba. Las cuatro especies de estudio se sembraron y registramos su germinación, establecimiento, supervivencia y crecimiento inicial durante dos meses. Resultados: El tratamiento de remoción de la copa no afectó significativamente la germinación. Lysiloma divaricatum tuvo la mayor probabilidad de germinación, la germinación más rápida y la mayor probabilidad de establecimiento, independientemente del tratamiento. Lonchocarpus torresiorum tuvo la mayor probabilidad de establecimiento en las parcelas sin cobertura de copa de M. acantholoba. La probabilidad de supervivencia de ambas especies fue más alta donde M. acantholoba fue removida por completo. Conclusiones: La germinación de las especies tolerantes a la sombra fue exitosa pero su supervivencia se inhibió por el denso dosel de M. acantholoba. La reducción de las copas de M. acantholoba puede estimular la recuperación de áreas forestales.

Abstract Background: Individual pioneer tree species often dominate early tropical dry forest succession and thereby affect possible successional pathways. Mimosa acantholoba var. eurycarpa is a highly dominant species in the tropical dry forest in Mexico. Hypothesis: Mimosa acantholoba var. eurycarpa exerts an inhibitory effect on the germination, establishment, survival, and early growth of light-demanding pioneers, while facilitating these processes for shade-tolerant old-growth forests species. Studied species: Lonchocarpus torresiorum, Lysiloma divaricatum, Mimosa acantholoba var. eurycarpa and Vachellia farnesiana. Study site and dates: Nizanda, Oaxaca, Mexico, 2020-2021. Methods: In 12 early successional plots, we applied three levels of crown cover removal (100, 50, and 0 %) of established trees of the dominant pioneer legume (M. acantholoba var. eurycarpa). We sowed seeds of the four study species in each experimental plot and recorded their germination, establishment, survival, and early growth over a 2-mo period. Results: The removal of crown cover of established M. acantholoba var. eurycarpa trees did not significantly affect germination. Lysiloma divaricatum had the highest germination probability, the fastest germination, and the highest establishment probability regardless of treatment. Lonchocarpus torresiorum had the highest establishment probability in plots where the crown cover of established M. acantholoba var. eurycarpa trees was removed. The survival probability of both shade-tolerant species was highest in the 100 % removal treatment. Conclusions: Despite successful germination of shade-tolerant species, their survival is inhibited under the dense canopy of the dominant legume. Therefore, interventions to reduce the crown cover area of this dominant legume may stimulate forest recovery.

Resumen Antecedentes: En la reforestación se recomiendan plantas nativas y en fuentes de la regeneración natural. Altos porcentajes de germinación bajo diferentes condiciones de luz y patrones fenológicos amplios incrementan la adaptación en ambientes heterogéneos. Se sugieren especies que tengan una dependencia a la inoculación con hongos micorrizógenos. Preguntas: ¿Solanum pubigerum está ampliamente distribuida en bosques templados del centro de México?, ¿en qué condiciones lumínicas germina?, ¿está en fuentes de la regeneración natural?, ¿la micorriza beneficia su germinación/crecimiento? Especie de estudio / descripción de los datos /Modelo matemático: Solanum pubigerum/distribución en bosques del centro de México, porcentajes de germinación y viabilidad, fenología reproductiva, dependencia micorrícica/Kruskal-Wallis, sincronía, correlaciones de Spearman, ANdeVA. Sitio de estudio y fechas: Bosque de Abies religiosa, Ciudad de México. Agosto 2019 - julio 2020. Métodos: Las semillas de S. pubigerum fueron expuestas a diferentes calidades de luz, su viabilidad fue monitoreada por dos años, así como su presencia en la regeneración natural. Se registró su fenología reproductiva, se inocularon plántulas con hongos micorrizógenos arbusculares para evaluar su crecimiento. Resultados: La mayor germinación ocurrió en luz blanca, la viabilidad se mantuvo en altos porcentajes después de dos años. S. pubigerum está en el banco de semillas en ambas épocas, fue menos abundante en la lluvia de semillas en la época seca, con un patrón de floración-fructificación amplio. La inoculación micorrícica incrementó su germinación y crecimiento. Conclusiones: Solanum pubigerum se recomienda para reforestar bosques del centro de México por sus germinación y respuesta a la micorrización.

Abstract Background: Plant species used for reforestation purposes are idoneous if native, and also if they are present in regeneration sources. High germination percentages under different light conditions and a broad phenological pattern enhance adaptability to environmental heterogeneity. Preference for species responsive to mycorrhizal inoculation is recommended. Questions: Is Solanum pubigerum a widespread species in temperate forests of central Mexico?, under which light conditions germination will be the highest?, how abundant is it in natural regeneration sources?, does inoculation with mycorrhizal fungi benefit its germination and growth? Studied species / data description / Mathematical model: Solanum pubigerum/distribution in central Mexico forests, germination and viability percentages, reproductive phenology, growth dependence on AM fungi/ Kruskal-Wallis test, synchrony, Spearman correlations, ANOVA. Study site and dates: Abies religiosa forest, Mexico City. August 2019 - July 2020. Methods: Seeds of S. pubigerum were exposed to different light qualities, their viability was monitored for two years. Its presence in natural regeneration sources was registered. Reproductive phenology was recorded, and seedlings were inoculated with arbuscular mycorrhizal fungi to assess their growth. Results: Highest seed germination occurred under white light conditions, with sustained viability after two years. The species was found in the seed bank across seasons, less abundantly in seed rain during the dry season. It exhibited extensive flowering and fruiting patterns. Mycorrhiza inoculation significantly boosted seed germination and growth. Conclusions: Solanum pubigerum is suitable for reforestation in central Mexico forests due to its high germination percentages and mycorrhizal responsiveness.

Resumen Antecedentes: Los mapas de bosques perturbados son útiles para identificar afectaciones sobre la biodiversidad y los servicios ecosistémicos. Los métodos que emplean únicamente datos espectrales para detectar las perturbaciones a nivel regional tienen limitaciones. El conocimiento de expertos y el análisis de fragmentación puede mejorar la estimación. Preguntas: ¿Cuál es la distribución de los bosques perturbados en una región de alta biodiversidad? ¿Qué tipos de vegetación y regiones son las más afectadas? Descripción de los datos: imágenes satelitales SPOT 2015, Sentinel-2 de 2019. Se colectó información de la vegetación en 653 sitios. Además, se usaron datos de herbario, censos agrícolas y del Inventario Nacional Forestal. Lugar y fecha del estudio: Estado de Chiapas, durante 2018-2022. Métodos: Se elaboró un mapa híbrido de los tipos de vegetación enfatizando la identificación de bosques secundarios, también se realizó un análisis de fragmentación y se calculó la biomasa leñosa por tipo de bosque. Resultados: El 40 % de la superficie del Estado mantiene una cobertura arbórea; pero solo en el 18 % no se aprecia perturbación; la mayor parte de los bosques no perturbados se encuentran en tres regiones: Selva Lacandona, Sierra Madre y Planicie del Golfo. En general la biomasa de los bosques perturbados es significativamente menor que la de su contraparte madura. Conclusiones: En Chiapas la distribución de los bosques en buen estado de conservación está restringida; casi la mitad de ellos se encuentran fuera de las ANP, por lo que es imperativo promover estrategias adicionales para su manejo y conservación.

Abstract Background: Maps of disturbed forests help to identify impacts on biodiversity and ecosystem services. Methods using only spectral data to detect disturbance at the regional level have limitations, but expert knowledge and fragmentation analysis can improve estimation. Questions: What is the distribution of disturbed forests in a region of high biodiversity, and which vegetation types and regions are most affected? Data description: SPOT 2015, Sentinel-2 satellite imagery from 2019. Vegetation data were collected at 653 sites. In addition, herbarium, agricultural census, and National Forest Inventory data were used. Study site and dates: Chiapas State, during 2018-2022. Methods: We elaborated a hybrid map of vegetation types, emphasizing identifying secondary forests. Also, we carried out a fragmentation analysis and calculated the woody biomass per forest type. Results: 40 % of the State still maintains tree cover, but only 18 % is undisturbed; most undisturbed forests are in three regions: Selva Lacandona, Sierra Madre, and Gulf Plain. Overall, the biomass of disturbed forests is significantly lower than that of their mature counterparts. Conclusions: In Chiapas, the distribution of forests with good conservation status is restricted; almost half of them are outside NPAs, so it is imperative to promote additional strategies for their conservation and management.

Abstract Fires affect more natural surfaces than any other disturbance factor on the planet. They result from the interaction of fuel, dry environmental conditions, and an ignition source. In the state of Michoacán conditions are conducive for the annual occurrence of numerous fires. Remote sensing offers global, consistent and objective information on fires, with the generation of series of burned areas, such as the 500m MCD64A1 generated from MODIS data. The objective of this work was to analyze this series to know the fires that occurred in the entity between 2015 and 2022, considering vegetation covers affected (INEGI Series VII) precipitation and temperature. An average of 3 340.87 pixels with fires were recorded annually; 2021, during confinement due to the Covid-19 pandemic, was the year with the most fires (5 269 pixels) and 2022 with the fewest (2 398). The fires are concentrated in the driest and hottest months, mainly May (1551.00 pixels on average) and April (958.38 pixels); the highest number was recorded in April 2021 (2 347 pixels), and the second month with the most detections was May 2020 (2 094 pixels). Most events are associated with agricultural burning (48.41%), mainly in irrigated land, in spring and winter. Forest fires significantly affect temperate forests and associated secondary vegetation (32.85%); in tropical deciduous forest areas (17.14%), fires occur mostly in secondary vegetation. In years with an early onset of rains (2015 and 2018), fewer fires accumulated.

Resumen Los incendios afectan a más superficies naturales que cualquier otro factor de disturbio en el Planeta. Resultan de la coincidencia de combustible, condiciones ambientales secas y una fuente de ignición. En el estado de Michoacán existen las condiciones propicias para la ocurrencia anual de numerosas conflagraciones. La teledetección ofrece información global, consistente y objetiva sobre los incendios, con la generación de series de áreas quemadas, como MCD64A1 de 500m, generada con datos MODIS. El objetivo de este trabajo fue analizar esta serie para conocer los incendios ocurridos en la entidad entre 2015 y 2022, considerando las coberturas afectadas (Serie VII de INEGI), la precipitación y la temperatura. Se contabilizaron al año, en promedio 3 340.87 pixeles con incendios; 2021, durante la pandemia de Covid-19, fue el año con el mayor número de registros (5 269 pixeles) y 2022 con menos (2 398). Los incendios se concentraron en mayo (1551.00 pixeles en promedio) y abril (958.38 pixeles); el máximo número de incendios se detectó en abril de 2021 (2 347 pixeles), seguido de mayo de 2020 (2 094 pixeles). La mayoría de los eventos se asocian a quemas agrícolas (48.41%) en terrenos de riego, en primavera e invierno; los incendios forestales afectan sobre todo a bosques templados y a la vegetación secundaria asociada (32.85%); en zonas de bosque tropical caducifolio (17.14%), los incendios ocurren, en su mayoría, en vegetación secundaria. En los años con un inicio temprano de la temporada de lluvias (2015 y 2018) se acumularon menos incendios.

Summary Background and aims: The most substantial global land use change is the transformation of native ecosystems into agroecosystems, leading to loss of biodiversity and reduction of ecosystem services. Potentially, these degraded systems could be restored from their soil seed bank. Our aim was to assess species richness and density of the soil seed bank along a structural complexity gradient in agroecosystems and Espinal forest fragments. Furthermore, we compared species composition between the soil seed bank and established vegetation of the reference system to explore its potential for regeneration of native plant communities. M&M: A structural complexity gradient was created from vegetation and soil structural variables from plots with different land uses to analyze seed bank variables. Results: The highest richness was recorded in the pasture soil seed bank, followed by the forests. The highest density and similarity to the established vegetation of the reference system was registered in the forests. Herbaceous species predominated in all plots. With the exception of Celtis tala, seeds of dominant woody species from the reference system were not observed. Conclusions: The pasture seed bank may be particularly relevant in the early stage of native forest restoration, especially if the aim is to reduce costs. However, the contribution of the seed bank to Espinal forests recovery in short to medium term is limited due to its low similarity to reference system.

Resumen Introducción y objetivos: El cambio de uso del suelo más significativo a nivel mundial es la transformación de ecosistemas nativos en agroecosistemas, causando pérdida de biodiversidad y servicios ecosistémicos. Potencialmente, estos sistemas degradados podrían recuperarse a partir del banco de semillas del suelo. Nuestro objetivo fue evaluar la riqueza y densidad del banco de semillas en relación con un gradiente de complejidad estructural en agroecosistemas y fragmentos de bosques del Espinal, así como su potencial para regenerar especies nativas comparando su composición de especies con la vegetación establecida del sistema de referencia. M&M: A partir de variables estructurales de vegetación y de suelo de parcelas con distintos usos de suelo, se construyó un gradiente de complejidad estructural sobre el cual se analizaron las variables del banco de semillas. Resultados: El banco de semillas de la pastura registró la mayor riqueza, seguida por el de bosques. La mayor densidad del banco de semillas y similitud con la vegetación establecida del sistema de referencia la presentaron los bosques. Predominaron las especies herbáceas en todas las parcelas. A excepción de Celtis tala, no se observaron semillas de especies leñosas dominantes del sistema de referencia. Conclusiones: El banco de semillas de la pastura puede contribuir en las primeras etapas de restauración, especialmente si se busca reducir los costos asociados a este proceso. Sin embargo, su aporte para recuperar los bosques nativos del Espinal en el corto o mediano plazo es limitado debido a su baja similitud con el sistema referencia.

Summary: Cyanobacteria are oxygenic phototrophic organisms that possess a high adaptive capacity to different environments, allowing them to pioneer terrestrial ecosystems. The objective of this study was to compare the cyanobacterial community in two areas of secondary mountain forest: one seven days after a fire (post-fire soil) and another nearby without fire (control soil). The collected samples were cultivated for 8 weeks under controlled conditions. A total of 35 taxa were identified: 2 unicellular, 24 filamentous without heterocytous, and 9 with heterocytous cyanobacteria; 13 of them represent the first record for soils in Córdoba.Microcoleus vaginatuswas the most frequent taxon, along withScytonema hoffmannii, Desmonostoc muscorum, andNostoc commune, which persisted until the end of the experiment. The presence of exclusive organisms such asCalothrix brevissima, Chlorogloeopsis fritschii,andCylindrospermum muscicolain the control soils highlights their sensitivity to this type of disruptive event in the community. The availability of nitrogen, CO content, and pH are the physicochemical soil variables that define the community structure. This work is contributing to increase our knowledge of soil restoration after forest fires.

Resumen: Las cianobacterias son los organismos fototróficos oxigénicos que poseen una alta capacidad adaptativa a diferentes ambientes, lo cual les permite ser pioneros en los ecosistemas terrestres. El objetivo del trabajo fue comparar la comunidad de cianobacterias en dos zonas de bosque serrano secundario, uno a siete días de ocurrido un incendio (suelo post-fuego) y otra próxima sin incendio (suelo testigo). Las muestras extraídas se cultivaron durante 8 semanas en condiciones controladas. Se identificaron un total de 35 taxones: 2 unicelulares, 24 filamentosas sin heterocitos y 9 con heterocitos; 13 de ellos constituyen primera cita para suelos de Córdoba.Microcoleus vaginatusfue el taxón más frecuente, junto conScytonema hoffmannii, Desmonostoc muscorumyNostoc communepermanecieron hasta finalizar el ensayo. Se destaca la presencia de organismos exclusivos tales como:Calothrix brevissima, Chlorogloeopsis fritschiiyCylindrospermum muscicolaen los suelos testigos, serían los taxones sensibles a este tipo de eventos disruptivos en la comunidad. La disponibilidad de nitrógeno, contenido de CO y pH son las variables físico-químicas del suelo que definen la estructura de la comunidad. Se considera que este trabajo aporta valiosa información para el avance del conocimiento de la restauración de suelos luego de los incendios forestales.

Abstract In this paper, I present the results of ethnographic research that analyzes the social effects on peasant communities (dedicated to working the land and fishing in the river) due to the delivery of compensation and the carrying out of works for the installation of the hydroelectric dam “El Quimbo”, located in the inter-Andean valleys of the Upper Magdalena River basin, in Huila, Colombia. Those lands were flooded in 2015, and affected people received different treatments that changed their relationships with the land, the river and their communities. Thus, the theoretical contribution of the article lies in the dialogue between ecological economics and economic anthropology, hence I describe the effects of restricting to a value paid in cash or measured in productivity regarding the social value of the elements present in the territory (land, river, forest) and community relations. Methodologically, six standard-situations were constructed inductively based on interviews and conversations collected in fieldwork that covered various moments between 2010 and 2021. The six standard-situations evince the effects on the social positions of affected groups: some partially reproduced their relations with the land; some began a situation of new subordination; and others were expropriated from the reproduction of their previous social relations. I complemented the article with secondary sources based on a review of archives, newspapers, and public documents of the company and the social movement.

Resumo No artigo, apresento os resultados de uma pesquisa etnográfica que analisa os efeitos sociais sobre as comunidades camponesas (dedicadas ao trabalho da terra e a pescaria no rio) pela entrega das compensações e a realização das obras na instalação do projeto hidrelétrico “El Quimbo”, localizado nos vales interandinos do Alto Magdalena, em Huila, Colômbia. Aquelas terras foram inundadas em 2015, e os atingidos receberam diferentes tratamentos que modificaram suas relações com a terra, o rio e suas comunidades. Assim, a contribuição teórica do artigo está no diálogo entre a economia ecológica e a antropologia econômica a partir da qual descrevo os efeitos de restringir o valor social dos elementos presentes no território (terra, rio, floresta) e das relações comunitárias por um valor a ser pago em dinheiro ou medido em produtividade. Metodologicamente, foram construídas de forma indutiva seis “situações-tipo” baseadas em entrevistas e conversas coletadas durante trabalho de campo, que abarcou vários momentos entre 2010 e 2021 e permitiu demonstrar os efeitos nas posições sociais ocupadas pelos atingidos: camponeses que puderam reproduzir parcialmente suas relações com a terra, aqueles que ficaram em uma situação de nova subordinação, e os que foram expropriados da reprodução de suas relações sociais anteriores. As informações foram complementadas com fontes secundárias baseadas em revisão de arquivos, jornais e documentos públicos da empresa e do movimento social.

Resumo Embora a acessibilidade ao ensino superior tenha melhorado em países de baixa e média renda (PBMR), a evasão persiste, especialmente entre estudantes socioeconomicamente desfavorecidos. Apesar dos avanços em modelos de Machine Learning para compreender esse desafio, muitos estudos negligenciam fatores institucionais específicos dos PBMR ou se concentram em cursos específicos, limitando sua aplicabilidade e relevância política. Para abordar isso, criamos uma base de dados usando registros administrativos e censitários para prever o desempenho acadêmico na Pontifícia Universidade Católica do Peru (PUCP). Os modelos mais eficazes, incluindo o Random Forest, destacaram preditores como desempenho prévio e pontuações em testes de admissão. Apresentamos um modelo eficiente com dez características que pode prever o desempenho futuro e assim contribuir para a redução da evasão na PUCP.

Abstract Despite improved higher education accessibility in low and middle-income countries (LMICs), challenges persist in student drop-out, especially for socio-economically disadvantaged students. While machine learning models have enhanced our understanding of this challenge by predicting academic performance, many studies overlook LMIC-specific institutional factors or focus on specific courses, limiting their generalizability and policy uses. To address these issues, the authors compiled a comprehensive database using administrative and census data to predict undergraduate academic performance at the Pontifical Catholic University of Peru (PUCP). The study found that the most effective models were tree-based ensembles, particularly Random Forest, with key predictors including prior secondary school performance and university admission test scores. They present a high-performing model using only ten features that can predict future academic performance and potentially aid in reducing student drop-out at PUCP.

Resumen Aunque la accesibilidad a la educación superior ha mejorado en países de renta baja y media (PRMB), persiste el abandono, especialmente entre estudiantes socioeconómicamente desfavorecidos. A pesar de los avances en modelos de Machine Learning para entender este desafío, muchos estudios descuidan factores institucionales específicos de los PRMB o se centran en cursos específicos, limitando su aplicabilidad y relevancia política. Para abordar esto, creamos una base de datos usando registros administrativos y censales para predecir el rendimiento académico en la Pontificia Universidad Católica del Perú (PUCP). Los modelos más efectivos, entre ellos Random Forest, destacaron predictores como el rendimiento previo y puntuaciones en pruebas de admisión. Presentamos un modelo eficiente con diez características que puede predecir el rendimiento futuro y así aportar a la reducción de la deserción en PUCP.

Abstract The concept of Natural Capital of the Romerillo forests (NCR) has been little studied in relation to the Education of this important type of natural capital. However, currently, many researchers have argued that Education can contribute significantly to the teaching and learning of this natural capital. By investigating how the concept has been studied, this article has attempted to establish the direction, understanding and use of Education that the NCR may take in the future, within the context of research into an Intangible Creative Ecological Economy (ICEE). This study used an exploratory research methodology with secondary information, in combination with chronological, conceptual and thematic literature review techniques. The literature review indicates that Education on NCR has been used in three areas of research to explain or address a particular construct: (1) promotion of formal and informal programs for use of the intangible environmental services, (2) development of an ICEE that promotes biotrade of intangible services from the Romerillos forests, and (3) short- and long-term conservation of the Romerillos forests. For future studies, it is recommended to address the concept of Education in “Intangible Forest Natural Capital” as a strategy for the sustainable use of the intangible environmental services of the NCR, aiming to mitigate deforestation and preserve the forests of the Romerillos Andean.

Abstract The genus Psidium, belonging to the family Myrtaceae, encompasses several plant species rich in essential oils. Several studies involving different research areas have shown promising results for essential oils, which has attracted interest from diverse sectors, including pharmaceutical, food, and cosmetic industries. Thus, the objective of this study was to evaluate the biological activity of the essential oil extracted from Psidium bahianum leaves (EOPb) collected in an Atlantic Forest remnant in the northern coast of the state of Bahia, Brazil. EOPb was extracted by steam distillation and analyzed through proton nuclear magnetic resonance (1H-NMR). The free radical scavenging activity was assessed using the DPPH methodology (analyzing the scavenging of the stable free radical 1,1-diphenyl-2-picrylhydrazyl). Antimicrobial disk diffusion assays were conducted; toxicity was determined through assays on sheep erythrocytes and Artemia salina. 1H-NMR evaluation showed the presence mainly of monoterpenes and sesquisterpenes. The percentage of antioxidant activity was 18.03±2.53 53 for 125 125 µg mL-1. Antimicrobial assays showed that the essential oil at a concentration of 10 mg mL-1 inhibited the growth of the microorganisms Staphylococcus aureus, Bacillus subtilis, B. cereus, Micrococcus luteus, Escherichia coli, Aspergillus niger, Candida albicans, and C. glabrata. The toxicity results indicated that concentrations of EOPb at 10, 100, 250, and 500 µg mL-1 were not toxic to sheep erythrocytes. The toxicity assay on A. salina showed that the lethal concentration for 50% of individuals (LC50) within 24 and 48 hours were 371.48 and 302 µg mL-1 of EOPb, respectively, which were considered moderately toxic, whereas the LC50 within 72 horas was 33.11 µg mL-1, considered highly toxic. These findings are promising, as the essential oil from P. bahianum leaves showed antimicrobial activity against both Gram-positive and Gram-negative bacteria and fungi. The data obtained for the essential oil toxicity in A. salina could be tested on different tumor cell lines. Myrtaceae oils sectors pharmaceutical food industries Thus (EOPb Bahia Brazil 1HNMR. 1HNMR HNMR 1H NMR . H (1H-NMR) analyzing 1,1diphenyl2picrylhydrazyl. 11diphenyl2picrylhydrazyl diphenylpicrylhydrazyl 1,1 diphenyl 2 picrylhydrazyl 1 1,1-diphenyl-2-picrylhydrazyl) conducted sesquisterpenes 1803253 18 03 18.03±2.5 5 12 mL1. mL1 mL 1. mL- aureus subtilis B cereus luteus coli niger albicans C glabrata 100 250 50 A LC (LC50 4 37148 371 371.4 30 respectively LC5 7 3311 33 11 33.1 mL1, 1, P Grampositive Gram positive Gramnegative negative fungi lines (1H-NMR 1diphenyl2picrylhydrazyl 1,1diphenyl2picrylhydrazyl 1,1-diphenyl-2-picrylhydrazyl 180325 0 18.03±2. 25 (LC5 3714 37 371. 3 331 33. 18032 18.03±2 (LC 1803 18.03± 180 18.03 18.0 18.

Resumo O gênero Psidium, pertencente à família Myrtaceae é rico em óleos essenciais que vêm sendo utilizados na indústria farmacêutica, alimentícia e na estética. Desse modo, o objetivo geral deste estudo foi avaliar a atividade biológica do óleo essencial de Psidium bahianum coletadas em remanescente de Mata Atlântica no Litoral Norte da Bahia, Brasil. O óleo essencial (OEPb) foi obtido das folhas do P. bahianum por arraste a vapor d'água. O OEPb foi analisado pela Ressonância magnética nuclear de H1. A atividade sequestradora de radicais livres foi avaliada pela metodologia de DPPH (analisando a eliminação do radical livre estável 1,1-difenil-2-picrilhidrazil). Foram realizados testes antimicrobianos em difusão em disco, e para a determinação da atividade tóxica realizou-se através dos ensaios em hemácias de carneiro e Artemia salina. O estudo de ressonância demonstrou principalmente a presença de monoterpenos, dentre eles o linalol, e sequisterpenos. A porcentagem da atividade antioxidante foi de 18,03 ± 2,53 53 para 125 µg /mL. No ensaio antimicrobiano o óleo essencial inibiu o crescimento dos microrganismos Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Escherichia coli, Aspergillus niger, Candida albicans e Candida glabrata testados na concentração de 10mg/mL. Os resultados da toxicidade demonstraram que nas concentrações de 10 e 100, 250 e 500µg/mL, o óleo essencial não é tóxico para hemácias de carneiro. No teste de toxicidade em Artemia salina, os resultados mostram que em 24 e 48 horas da DL50 é de 371,48 e 302µg/mL de óleo essencial sendo considerados moderadamente tóxicos e em 72 horas a DL 50 é de 33,11µg/mL considerado altamente tóxico. Os dados alcançados são promissores, uma vez que o óleo essencial de P. bahianum demostrou atividade antimicrobiana para bactérias Gram positiva e negativa e para fungos. Os dados obtidos de toxicidade em A. salina para o óleo essencial poderá ser testado em diferentes linhagens tumorais. farmacêutica estética modo Bahia Brasil (OEPb P dágua. dágua d água. água d'água H1 H analisando 1,1difenil2picrilhidrazil. 11difenil2picrilhidrazil difenilpicrilhidrazil 1,1 difenil 2 picrilhidrazil . 1 1,1-difenil-2-picrilhidrazil) disco realizouse realizou se monoterpenos linalol sequisterpenos 1803 18 03 18,0 253 2,5 5 12 mL /mL aureus subtilis cereus luteus coli niger 10mgmL mgmL 10mg mg 10mg/mL 100 25 500µgmL µgmL 500µg 500µg/mL 4 DL5 37148 371 371,4 302µgmL 302µg 7 3311µgmL 33 11µg promissores fungos tumorais 1difenil2picrilhidrazil 1,1difenil2picrilhidrazil 11 1, 1,1-difenil-2-picrilhidrazil 180 0 18, 2, 3714 37 371, 3

Abstract The study investigated ash development in an arid region, focusing on its invasive spread mechanisms at organismic and ecosystem levels under varying moisture conditions. Conducted in the Northern Caspian region’s Volga-Urals interfluve, it examined the effects of arid climate, soil salinity, and limited moisture on plant communities. The features of ash functioning at the organismal and ecosystem levels with permanent and partial deficiency of productive moisture in the soil, as well as with its optimal availability, were investigated. It is shown that on automorphic soil types, ash cultures, subject to appropriate forestry technologies, can exist for many decades even during periodic soil droughts due to premature harmless dumping of leaf mass. In hydromorphic floodplain conditions, ash is not only well preserved in cultures, but also effectively introduced into meadow and forest ecosystems by lowering the relief. Trees in a new place, especially in meadows, begin to bear fruit after 6-10 years and spread the seeds to other territories. Such a nomadic strategy of stepwise dispersed multiple dispersal of ash contributes to the rapid formation of its secondary invasive areas and eliminates the possibility of effective control against it. Therefore, the use of ash in industrial plantings in floodplains is highly inadvisible. region conditions regions s VolgaUrals Volga Urals interfluve climate salinity communities availability types cultures technologies mass relief place meadows 610 6 10 6-1 territories Therefore inadvisible 61 1 6-

Resumo O presente estudo investigou o desenvolvimento do freixo da Pensilvânia em uma região árida, concentrando-se nos mecanismos de sua propagação invasiva a nível organísmico e ecossistêmico, sob condições variáveis de umidade. Realizado no interflúvio Volga-Urais da região norte do Cáspio, foram examinados os efeitos do clima árido, da salinidade do solo e da umidade limitada nas comunidades vegetais. As características do funcionamento do freixo a nível de organismo e de ecossistema foram investigadas tanto em relação à deficiência permanente e parcial de umidade produtiva no solo, quanto a sua disponibilidade ideal. Foi possível observar que culturas de freixo sujeitas a tecnologias florestais apropriadas podem existir por muitas décadas em solos não-hidromórficos, mesmo durante secas periódicas, devido ao seu processo de desfolha precoce e inofensiva. Além de apresentar uma boa adaptação em culturas com condições de solos hidromórficos em planícies aluviais, a introdução do freixo em ecossistemas de prados e florestas é igualmente bem-sucedida após a nivelação do relevo. Árvores plantadas em um novo local, especialmente em prados, começam a frutificar após 6-10 anos e assim disseminam suas sementes para outros territórios. Tal estratégia nômade de dispersão múltipla e gradual contribui para a sua rápida invasão de áreas secundárias e elimina a possibilidade de um controle eficaz contra o freixo. Portanto, o plantio de freixo em cultivos para fins industriais em planícies aluviais é altamente desaconselhável. árida concentrandose concentrando se ecossistêmico VolgaUrais Volga Urais Cáspio árido vegetais ideal nãohidromórficos, nãohidromórficos não hidromórficos, não-hidromórficos periódicas inofensiva bemsucedida bem sucedida relevo local 610 6 10 6-1 territórios Portanto desaconselhável 61 1 6-