Functional attributes, environmental cues, and phylogeny interact with each other to shape the diversity of flowering patterns. Phenological differentiation among species groups revealed multiples strategies associated with growth form and pollination syndromes that can be important for understanding species coexistence in this highly diverse plant community.

ResumenDerivado del trabajo de campo realizado entre 2012 y 2016, se describen los 2 tipos de bosque tropical (caducifolio y subcaducifolio) y la flora vascular del ejido Llano de Ojo de Agua, ubicado en la Depresión del Balsas (Michoacán). Se registraron 466 especies (2 subespecies), que representan 303 géneros y 84 familias. Fabaceae (83 especies), Euphorbiaceae (34) y Asteraceae (32) destacaron por su riqueza, mientras que en la categoría de género, lo fueron Bursera, Ipomoea (cada uno con 14 especies) y Euphorbia (13). El endemismo de la flora a escala del país fue de 41.1% (192 especies), 4.1% (19) para la Depresión del Balsas, con 7 especies restringidas a Michoacán. Las hierbas fueron la forma de crecimiento más frecuente (216 especies, 46.3%), seguidas por los árboles (155, 33.2%). Un total de 98 especies se encuentran asignadas bajo alguna categoría de riesgo. Se confirma la importancia florística de la Depresión del Balsas y la pertinencia de continuar con su inventario en áreas poco exploradas.

Ficus (Moraceae) is one of the most diverse genera of tree species in the world. The subgenus Spherosuke, section Americanae, comprises several species complexes because its diagnostic structures are extremely variable. Currently, neither there is a phylogenetic hypothesis that can help solve the delimitation problems within these complexes nor has an integrative taxonomic approach been developed. In the present study, morphometric methods were applied to solve the taxonomic problems in the Ficus aurea complex. Morphometric variation of syconia and leaves was analyzed to find differences between four previously recognized forms (fo. aurea, fo. cookii, fo. isophlebia, and fo. tuerckheimii). Syconium characters were analyzed using traditional morphometrics, while leaf shape was evaluated with geometric morphometrics, encompassing 20 populations along two-thirds of the distribution range of the complex. Data sets from syconia and leaves were tested for possible associations with geographic and rainfall variables. There are significant differences between the four forms in syconium characters and leaf shape. Geography and rainfall variables show significant covariation related to the morphometric variation of syconia but not to leaf shape. Consequently, we propose that the four forms should be repositioned into the specific rank. Besides, F. tecolutensis is also recognized as a separated species from form aurea considering Principal Component Analysis, field observations, and herbarium specimens. An identification key, descriptions, as well as taxonomic comments of the species are provided.

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.

Background: Phenotypic and functional traits of plant populations vary with environmental conditions at local and regional scales. The analysis of these traits along environmental gradients provides information on the differential response of populations to climate changes. Objective: We analyzed the leaf morphological variation of an endemic oak to identify the degree of population differentiation along an environmental gradient. Study species: Quercus mexicana Bonpl. (Fagaceae). Study site and dates: Samples were collected from 39 populations in the Sierra Madre Oriental and east of the Trans-Mexican Volcanic Belt from 2014 to 2016. Methods: We measured eight macromorphological traits in 5,507 leaves and three micromorphological traits in 228 leaves. We performed univariate and multivariate statistical analyses to assess the morphological differentiation among populations, and the relationship between variation in leaf traits and environmental variables related to temperature and water availability. Results: Populations of Q. mexicana showed leaf morphological differentiation along its distribution. Significant linear correlations were found between leaf traits and environmental variables. Smaller and thicker leaves with lower density of trichomes and smaller stomata were found in populations located in more arid regions. In contrast, larger and thinner leaves with higher trichome density and larger stomata occurred in more humid places. Conclusions: Populations of Q. mexicana are adapted to a wide range of climatic conditions. Considering the predictive future climatic changes for the region (i.e., warmer and drier conditions), Q. mexicana populations with traits better adapted to a more humid and cooler environments could be negatively affected.