Amazon rainforests face intensifying water stress due to increases in vapour pressure deficit and changing hydrological regimes. Embolism resistance (Ψ50) is a critical metric of tree survival under drought conditions, it is defined as a plant's capacity to resist disruption of xylem water flow due to air bubble formation from water stress. However, measurements of Ψ50 are only available for a limited number of Amazon locations and species. Conversely, data on forest taxonomic composition are abundant across Amazonia, and if Ψ50 is conserved phylogenetically, these data could provide a way to scale-up drought resistance patterns. Here we evaluate Ψ50 measurements across non-flooded Amazonian tree taxa and reveal a moderate phylogenetic signal, with phylogenetic conservatism evident at the family-level. Notably, Fabaceae is amongst the most embolism-resistant tree families in Amazonia. Leveraging the phylogenetic signal we use species composition and tree size data from 448 forest plots across Amazonia to produce a macroecological assessment of Amazonian vulnerability to embolism. The resulting estimate spatial pattern reveals that forests in the Brazilian and Guiana Shield regions, where Fabaceae abundance is high, show strong resistance to embolism. In contrast, tree communities in Western Amazonia appear more vulnerable to embolism, suggesting a reduced capacity to withstand future drought conditions.
La presente investigación evalúa la fenomenología de la Isla de Calor Urbana (ICU) en la parroquia Universidad de Ciudad Guayana mediante el uso de sensores remotos y sistemas de información geográfica (SIG). El objetivo consistió en determinar la correlación espacial entre la Temperatura Superficial Terrestre (TST), el Índice de Vegetación de Diferencia Normalizada (NDVI) y la configuración del relieve. Se aplicó una metodología de diseño documental-tecnológico procesando imágenes satelitales Landsat 8 y 9 (OLI/TIRS) bajo el sistema UTM Zona 20N. Los resultados revelan un gradiente térmico crítico con máximos de 47,8 °C en zonas de alta densidad constructiva, como el Guayana Country Club y Alta Vista, contrastando con un NDVI mínimo de -0,04 que evidencia la pérdida de biomasa reguladora. El análisis de orientación de laderas (Aspect) y sombreado (Hillshade) confirmó una exposición solar ininterrumpida que potencia la acumulación calórica en el tejido urbano consolidado. Se concluye que el sellado del suelo y la geometría urbana actúan como determinantes de anomalías térmicas, sugiriendo la implementación de infraestructuras verdes como estrategia de mitigación bioclimática.
We provide a comprehensive examination of agent-based approaches that codify the principles and linkages underlying multi-agent systems, simulations, and information systems. Based on two decades of study, this paper confirms a framework intended as a formal specification for geosimulation platforms. Our findings show that large language models (LLMs) can be effectively incorporated as agent components if they follow a structured architecture specific to fundamental agent activities such as perception, memory, planning, and action. This integration is precisely consistent with the architecture that we formalize, providing a solid platform for next-generation geosimulation systems.
El presente estudio analiza el impacto de la violencia sexual en universidades ecuatorianas, considerando estudiantes, docentes y personal administrativo femenino. La investigación tiene como objetivo identificar la prevalencia de esta problemática, su efecto en el desempeño académico y profesional, y evaluar la respuesta institucional. Utilizando un diseño mixto, con encuestas y entrevistas a 40 estudiantes y 40 trabajadoras universitarias, se identificó que el 68.5% de las participantes han experimentado acoso sexual y el 32.5% violencia sexual directa. Además, el 82.5% considera inadecuada la respuesta institucional y solo el 27.5% conoce los protocolos de denuncia. Los resultados reflejan consecuencias graves, incluyendo impactos psicológicos como ansiedad y dificultades interpersonales, y un deterioro en el desempeño académico y profesional. El estudio concluye que las universidades carecen de políticas efectivas para abordar esta problemática y resalta la necesidad urgente de implementar estrategias integrales de prevención y atención. Este trabajo contribuye al entendimiento de la violencia de género en contextos educativos, sentando las bases para investigaciones y acciones futuras.
Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.
