Guillermo Ibarra-Manríquez

Background: The role of topography in the spatial variation of tropical rainforest (TRF) community attributes remains insufficiently understood. We analyze community attributes in a newly-established 1-ha plot located in the 'Strongly dissected slopes' land unit in a Neotropical TRF and compare them with those assessed in an older 1-ha plot located in the 'Piedmont' land unit. Questions: What is the magnitude of topography-related spatial variation of TRF community attributes across a single locality? Does this variation influence the comparison of this TRF with similar forests worldwide? Study Site and Years: Los Tuxtlas Tropical Biology Station (Veracruz, southern Mexico); 2018-2019. Methods: We assessed community attributes (composition, structure, diversity) in the new plot by censusing all woody plants with DBH ≥ 1 cm. Results: We recorded 4,375 individuals (basal area, 43.35 m2), 188 species, and 58 families. Fifteen families, including Arecaceae, Moraceae, and Meliaceae, accounted for a large proportion of species (57 %), individuals (86 %), and basal area (79 %). Most recorded plants (90 %) had DBH ≤ 10 cm. The evenness factor indicated high dominance in the community. The plots differed primarily in species and family composition, individual density, and vertical structure. Conclusions: The community attributes of the TRF analyzed in plots located in different land units showed low variation. When compared with other TRFs worldwide, the Los Tuxtlas forest stands out for its low individual density and diversity but its higher basal area. Including the study site’s complex topography in this analysis did not significantly affect previous interregional comparisons.

Antecedentes: Morelia es el municipio de Michoacán mejor conocido florísticamente, debido a diversos trabajos florísticos y taxonómicos, así como a un alto número de especímenes de herbario. Sin embargo, es necesario integrar y actualizar esta información. Pregunta: ¿Cuál es la riqueza, endemismo y distribución geográfica de la flora vascular del municipio de Morelia? Especies estudiadas: Plantas vasculares. Sitio de estudio y fechas: Municipio de Morelia; 2007-2024. Métodos: Se elaboró una lista florística a partir de recolectar muestras botánicas, la consulta de ejemplares de herbario, la revisión de bases de datos y de literatura florístico-taxonómica. Resultados: Se enlistan 168 familias, 731 géneros, 1,867 especies y 113 taxa infraespecíficos de plantas vasculares. La mayor riqueza se registró en Asteraceae (321 especies), Poaceae (186) y Fabaceae (126), así como en los géneros Salvia (33), Euphorbia (30) y Muhlenbergia (27). Las hierbas fueron la forma de crecimiento más importante (80.6 %). La vegetación secundaria y los bosques de Quercus y de Pinus-Quercus destacan por su riqueza florística. El 35.7 % de los taxa son endémicos de México y el 23.4 % de las especies están clasificadas en alguna categoría de riesgo, de acuerdo con la NOM-059 y la Lista Roja de la IUCN. Conclusiones: Morelia alberga casi una tercera parte de la riqueza florística de Michoacán. La mayoría de las especies son nativas (93.5 %). Se espera que la información contenida en este trabajo contribuya al desarrollo de estudios biológicos y socioambientales realizados en el municipio y apoye la conservación de su flora.

Plant communities are unevenly distributed in space, shaped by both abiotic and biotic factors. Several methods have been developed for delineating their extent, including the spatial analysis of vegetation patterns using tools such as vegetation maps, climate-based simulations, and the use of characteristic species distribution. However, limited knowledge exists about which species are most suitable for this purpose. In this study, we aimed to delimit the seasonally dry tropical forest (SDTF) in Mexico based on the distribution area of vascular plant species endemic to Mexico and registered to this biome. Endemic species serve as key indicators for delineating biomes, highlighting regions with stable conditions and unique evolutionary and biological characteristics. The occurrence records of species were obtained from the Global Biodiversity Information Facility (GBIF) database, and ecological niche models were generated using the ENMTML package in R. The boundaries of the SDTF were delineated by stacking species distribution models, grouping endemic species according to the proportion of their occurrence records located within the SDTF: i ) ≥50% of records (SDTF 50%), ii ) ≥75% (SDTF 75%), and iii ) 100% (SDTF 100%). Model performance was evaluated using Kappa, sensitivity, and specificity metrics. We validated our results using Asteraceae points distributed across Mexico’s major biomes and analyzed confusion matrices. A total of 3,673 endemic species were registered, and 228 met the criteria for species distribution modeling. Of these, 96% yielded models with high predictive accuracy. Among the three approaches, the model based on high-affinity species (SDTF 75%) performed best in terms of all evaluation metrics, delineating approximately 14% of Mexico’s surface as SDTF. In conclusion, high-affinity species serve as reliable indicators for delineating plant communities with well-defined environmental characteristics, facilitating both the precise delineation of biomes and their application in conservation ecology and in other biomes.

El objetivo principal del presente trabajo es actualizar la nomenclatura y el inventario de las especies registradas en la Estación de Biología Tropical Los Tuxtlas (ELT), localizada en el estado de Veracruz, con base en la consulta de literatura florístico-taxonómica, ejemplares de herbario, bases de datos electrónicas y taxónomos. Se registran 934 especies, 571 géneros y 139 familias. Las 20 familias con mayor número de especies abarcan 58.8% de la flora, destacando Orchidaceae (108 especies), Asteraceae (61) y Fabaceae (58); los géneros más relevantes fueron Epidendrum (16), Piper (14) y Ficus (10). Un total de 48 familias (34.5%) y 410 géneros (71.8%) están representados por una especie. Las formas de crecimiento más frecuentes son las hierbas (453 especies, 48.5%) y árboles (259, 27.7%). Noventa y tres especies (10%) son endémicas de México. Las especies de la ELT que se comparten exclusivamente con Centroamérica son las más frecuentes (29.8%), seguidas por las que se registran conjuntamente en Centroamérica, Antillas y Sudamérica (23.2%). Se enfatiza la importancia de continuar con el inventario de esta reserva ubicada en una de las regiones con mayor tasa de deforestación en México.

Determining species' maximum sizes provides valuable insights into their ecology, natural history, and potential ecosystem contributions. Using both plot‐based and forest‐wide surveys on six continents, we document the largest “Champion” liana ever recorded (866 mm diameter) from an African forest, as well as continental Champions Lianas from around the world.

Las semillas de chía son consideradas un súper alimento por su alto contenido de proteínas, ácidos grasos, vitaminas y minerales. Pero, ¿sabías que la chía es en realidad una especie de Salvia, pariente cercana de la albahaca, la menta, el tomillo y el toronjil? En este artículo descubrirás la gran diversidad de salvias que crecen en México, aprenderás a reconocerlas y conocerás dónde se encuentran en estado silvestre o cómo cultivarlas. Además, exploraremos otros usos de las salvias más allá de las semillas de chía, desde sus propiedades medicinales hasta su valor ornamental. Más que sólo plantas bonitas o nutritivas, las salvias son parte vital de nuestros ecosistemas y culturas. Entenderlas es el primer paso para valorarlas y conservarlas, porque proteger nuestra biodiversidad comienza por conocerla.

The mutualism between Ficus species (Moraceae) and their pollinating wasps (Agaonidae) is a widely recognized coevolutionary model. In Ficus species from the Paleotropic, it has been determined that the ostiole acts as a morphological filter that affects the head dimensions of pollinating female wasps. Here, for the first time, the allometric relationship between ostiole size (diameter and length) and the shape of the head (length/width) of pollinating wasps is quantitatively explored in 6 Neotropical Ficus species (3 sect. Americanae and 3 sect. Pharmacosycea). In the case of sect. Americanae, wasp head shape was significantly correlated only with ostiole length, while in sect. Pharmacosycea both ostiole variables were correlated with head shape. The ordination analysis (NMDS) clearly reflected associations of these traits in species for both sections. The results support what has been interpreted in previous studies as reciprocal evolution between the analyzed traits, which contribute, along with other morphological and ecological traits, to the specificity between Ficus species and their pollinating wasps.