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Background: Heteroflorum (Fabaceae) is a monospecific genus endemic to western Mexico. Community attributes of the forest where H. sclerocarpum is found are scarcely known, as well as its similarity with other tropical seasonal forests. Question: What is the composition, structure, and diversity of the tropical deciduous forest where H. sclerocarpum is physiognomically dominant? Study site and date: The study was carried out in the buffer area of the Zicuirán-Infiernillo Biosphere Reserve, in the Churumuco municipality of Michoacán, Mexico (2014). Methods: In three 0.1-ha sites, we sampled trees with a diameter at breast height ≥ 1 cm and lianas whose rooted stem had a diameter of ≥ 1 cm. We calculated the density, biomass, rank-abundance, rank-basal area curves, and alpha and beta diversity measures for each site. Results: We recorded 64 species from 21 families in 0.3 ha. Fabaceae had the highest number of genera, species, individuals, and biomass in all sites sampled. The sites varied in richness (33-41 species), density (176-247 individuals), basal area (2-2.9 m2), and maximum height of trees (12-16 m). Rank-abundance curves differed significantly. Rarefaction curves showed that 0Dα and 1Dα did not differ among sites, while 2Dα separated one of the sites, which also showed a different diversity profile. Beta diversity did not show a strong species turnover among sites (0Dβ, 1.38-1.45; 2Dβ, 1.35-1.56). Conclusions: The composition of trees and shrubs in the forest sampled was similar to other seasonal forests, while the density and diversity were among the lowest values.

Vegetation is a key biosphere component to supporting biodiversity on Earth, and its maintenance and proper functioning are essential to guarantee the well-being of humankind. From a broad perspective, a fundamental goal of vegetation ecology is to understand the roles of abiotic and biotic factors that affect vegetation structure, distribution, diversity, and functioning, considering the relevant spatial and temporal scales. In this contribution, we reflect on the difficulties and opportunities to accomplish this grand objective by reviewing recent advances in the main areas of vegetation ecology. We highlight theoretical and methodological challenges and point to alternatives to overcome them. Our hope is that this contribution will motivate the development of future research efforts that will strengthen the field of vegetation ecology. Ultimately, vegetation science will continue to provide a strong knowledge basis and multiple theoretical and technological tools to better face the current global environmental crisis and to address the urgent need to sustainably conserve the vegetation cover of our planet in the Anthropocene.

Background: Lianas are an important woody component of tropical rain forests. We described and compared the composition, structure, and diversity of the liana community in one of the northernmost neotropical rain forests. Question: How much does this liana community differ in attributes with global patterns documented in other tropical and subtropical rain forests? Study site and dates: Los Tuxtlas Tropical Biology Station, Veracruz, Mexico. 2015-2018. Methods: We censused all lianas ≥ 1 cm in diameter in a 1-ha plot and determined dominant families and species, diametric distribution, and diversity of order q. Results: We recorded 396 liana stems, 42 species, and 20 families. Basal area was 6619.2 cm2. Order 1 and 2 diversity was 21.9 and 13.4, respectively. Apocynaceae, Bignoniaceae, Celastraceae, and Malpighiaceae accounted for about 60 % of abundance and basal area, and 45.2 % of species richness. The 10 most abundant species included more than 60 % of stems and basal area. Conclusions: Species richness, abundance, and basal area were low compared with other tropical and subtropical sites worldwide. It was noteworthy the coincidence of some dominant species and families across the Neotropics and the absence of Fabaceae among the most important families. Latitudinal location and some key climatic factors such annual average rainfall and dry season length may explain, in part, our findings.

Antecedentes: El género Ficus incluye aproximadamente 850 especies, distribuidas en zonas tropicales de todo el mundo y para un bajo número de ellas, se ha descrito el desarrollo del sicono. El presente estudio aborda este tópico, caracterizando los cambios morfo-anatómicos del sicono de F. tuerckheimii. Pregunta: ¿Las fases de desarrollo del sicono de F. tuerckheimii difieren en sus atributos morfo-anatómicos? Especies de estudio: F. tuerckheimii (Moraceae). Sitio y años de estudio: Veracruz, México (2018-2019). Métodos: Se recolectaron siconos para describir la morfología, anatomía, color y tamaño en las diferentes fenofases de su desarrollo. Los siconos se fijaron para ser procesados e incluidos en paraplast y descritos mediante microscopía de luz o microscopía electrónica de barrido. Resultados: Las fases de desarrollo difirieron en tamaño, así como en el color de la pared siconial y del ostíolo, particularmente en las fases más críticas de su interacción con polinizadores o dispersores (fases B, D y E). Las brácteas externas del ostíolo y el anillo ostiolar presentaron tricomoides; en la parte externa y basal del anillo ostiolar se registraron osmóforos. El registro de peines coxales y corbículas en la avispa hembra de Pegoscapus sp. indica que realiza una polinización activa. Conclusiones: Las características morfoanatómicas de las fases de desarrollo del sicono en F. tuerckheimii son similares a las documentadas en otras especies del género. Sin embargo, existen diversos aspectos que deben explorarse con más detalle, con el objeto de determinar su similitud con otras poblaciones en las que se distribuye la especie en México y Centroamérica.

Background: Knowing the floristic composition of the Monarch Butterfly Reserve is a critical piece of information necessary for its conservation. Question/Hypothesis: i) How many plant species (total and endemic to Mexico) are found in the core zones of the Monarch Butterfly Biosphere Reserve (MBBR)? ii) What are the most frequent growth forms found in this reserve? iii) What is the species diversity for the different types of vegetation? and iv) What is the floristic similarity among the core zones? Studied species/ Data description/ Mathematical model: Ferns, Gimnosperms and Angiosperms. Study site and years of study: The three core zone (Cerro Altamirano, Cerro Pelón and Chincua-Campanario-Chivati) of the MBBR were studied from 2000 to 2006. Methods: A total of 49 field trips were conducted over three years (2004 to 2006) to the core zones, and previously collected specimens (2000-2003) were revised in the IEB herbarium. Beta diversity among the core zones was estimated by calculating Jaccard index (JI). Results: A total of 97 families, 337 genera, 694 species and 20 infraspecific categories were inventoried. Asteraceae (147 species) and Fabaceae (37), as well as Salvia (23), Quercus (12) and Stevia (12) were the most diverse taxa. Herbaceous plants were the predominant growth form (ca. 75 %). The vegetation types with the greatest number of species were forests dominated by Quercus (427) and by Abies (329). About 38 % of species documented are endemic to Mexico. The core zones show high beta diversity values (Jaccard index 0.03 to 0.11); more of the half of the total number of species documented (66.3 %) was found exclusively in one core zone. Conclusions: The core zones are complementary in terms of plant conservation purposes and require similar conservation resources in order to secure important long-term maintenance of the biodiversity and forest cover that serve as winter refuges of the migrant Monarch butterfly populations.

Mediante una revisión de información bibliográfica y de herbario, se analizó el espectro de dispersión de árboles y lianas de localidades con bosque tropical caducifolio en América, con el objetivo de determinar si este atributo se modifica al considerar diferentes conjuntos florísticos, como floras leñosas regionales o parcelas de muestreo de 0.1 ha. Para estas últimas, se cuantificó el grado de similitud del espectro de dispersión, obtenido mediante el conteo de especies o por el número de individuos. A una escala local, las proporciones de los síndromes de dispersión fueron similares entre la flora y lo obtenido en los muestreos, pero los síndromes de dispersión difirieron entre sí de manera significativa. A nivel Neotropical, el análisis entre tres floras también varió significativamente entre síndromes. Las comparaciones entre parcelas mostraron que existen diferencias significativas entre localidades, tanto entre síndromes de dispersión como entre la interacción síndrome-localidad. Este resultado persiste al analizar formas de crecimiento de manera independiente o considerando su abundancia. Las divergencias encontradas entre localidades no fueron explicadas por la latitud o variables climáticas; pero tanto a nivel local como Neotropical, estas son más claras para las formas de crecimiento, ya que la zoocoria es más importante para árboles y la anemocoria para lianas. Los resultados constatan la complejidad del fenómeno de la dispersión de especies leñosas del bosque tropical caducifolio, por lo que futuros estudios deberán indagar con más detalle la influencia de la escala espacial, así como factores proximales e históricos.

Background and AimsWhen ecologically important plant traits are correlated they may be said to constitute an ecological ‘strategy’ dimension. Through identifying these dimensions and understanding their inter-relationships we gain insight into why particular trait combinations are favoured over others and into the implications of trait differences among species. Here we investigated relationships among several traits, and thus the strategy dimensions they represented, across 2134 woody species from seven Neotropical forests.MethodsSix traits were studied: specific leaf area (SLA), the average size of leaves, seed and fruit, typical maximum plant height, and wood density (WD). Trait relationships were quantified across species at each individual forest as well as across the dataset as a whole. ‘Phylogenetic’ analyses were used to test for correlations among evolutionary trait-divergences and to ascertain whether interspecific relationships were biased by strong taxonomic patterning in the traits.Key ResultsThe interspecific and phylogenetic analyses yielded congruent results. Seed and fruit size were expected, and confirmed, to be tightly related. As expected, plant height was correlated with each of seed and fruit size, albeit weakly. Weak support was found for an expected positive relationship between leaf and fruit size. The prediction that SLA and WD would be negatively correlated was not supported. Otherwise the traits were predicted to be largely unrelated, being representatives of putatively independent strategy dimensions. This was indeed the case, although WD was consistently, negatively related to leaf size.ConclusionsThe dimensions represented by SLA, seed/fruit size and leaf size were essentially independent and thus conveyed largely independent information about plant strategies. To a lesser extent the same was true for plant height and WD. Our tentative explanation for negative WD–leaf size relationships, now also known from other habitats, is that the traits are indirectly linked via plant hydraulics. [ABSTRACT FROM AUTHOR]