Palmarola, Alejandro

La distribución de las plantas epífitas está influenciada por las características de su forófito, que provee el sustrato necesario para el establecimiento. Encyclia pyriformis (Lindl.) Schltr. es una especie característica de las arenas blancas del Occidente de Cuba, con una distribución restringida, lo cual es un elemento clave para el manejo y mantenimiento de la población en el tiempo. El objetivo del trabajo es caracterizar el uso del microhábitat de E. pyriformis y analizar la relación entre las variables ambientales y morfológicas. El estudio se realizó en 39 parcelas (25 m2), en la Reserva Ecológica Los Pretiles. Se identificaron a los individuos de E. pyriformis, en los cuales se midieron seis variables ambientales y cuatro morfológicas. Los valores promedios de las variables ambientales fueron de 9.42 cm de diámetro del tronco, 66.58% de cobertura vegetal, 373 m de distancia a la costa, 0.84 m de altura sobre el suelo y 2.37 m de altura del forófito. Para las variables morfológicas los valores promedios fueron de 24.9 cm para altura del individuo, 1.87 cm de diámetro del pseudobulbo, 13.62 cm y 2.06 cm de largo y ancho de la hoja, respectivamente. No se encontró correlación entre las variables ambientales y morfológicas. La ausencia de correlación entre los dos grupos de variables parece indicar que la combinación de variables ambientales analizadas no tienen un efecto evidente sobre la morfología de los individuos de E. pyriformis. Entender los factores ambientales que limitan y afectan la distribución de las especies es crítico para el mantenimiento de la diversidad. Identificar los factores que limitan el potencial de colonización de las orquídeas permitiría predicciones certeras ante cambios futuros en la comunidad y el ecosistema, lo cual puede influir en las estrategias de manejo de la especie.

The Cuban ultramafic areas support the highest plant diversity and endemism of the island and are frequently damaged by human activities. In this work we hold up the importance of "El Tibisial" for conserving the ultramafic flora of Guamuhaya region. The 73.3 % of Guamuhaya ultramafic flora and 49 of the 55 endemic plants reported to this region occurs at "El Tibisial" area. In this area 67 species are useful for humans. This area supports two types of plant communities: the spiny xeromorphic thicket on serpentine soil and the secondary spiny xeromorphic thicket on serpentine soil.

The reduction of all genera of Magnolioideae (Magnoliaceae) to one single genus Magnolia s.l. is generally accepted by recent taxonomical treatments worldwide. As species of genus Talauma were designated under the genus Magnolia, the Cuban species of the genus Talauma were mechanically considered synonyms of Magnolia minor, the only Cuban Talauma with a valid name that fit into the new concept of the genus Magnolia. In this paper, we review the taxonomy and nomenclature of the genus Magnolia sect. Talauma in Cuba considering the literature, the protologue, type specimens and other specimens available. The section Talauma of the genus Magnolia in Cuba were described and the three Cuban species of this section: Magnolia minor and the two new combinations Magnolia oblongifolia and Magnolia orbiculata were presented and also prepare an identification key of the three species. The herbarium specimens available do not allow differentiating Talauma ophiticola from Magnolia oblongifolia. We also provide data on the distribution, conservation status, and ethnobotany of the three species.

Genetic data on threatened plant populations can facilitate the development of adequate conservation strategies to reduce extinction risk. Such data are particularly important for species affected by habitat fragmentation such as Magnolia cubensis subsp. acunae, a Critically Endangered magnolia subspecies endemic to Cuba. Using genetic data from 67 individuals, we aimed to evaluate the effect of habitat fragmentation on two subpopulations in the Guamuhaya mountain range, in Topes de Collantes Protected Natural Landscape and Lomas de Banao Ecological Reserve. We characterize the structure and genetic diversity of these subpopulations, with the objective of managing their conservation more effectively. We used Landsat satellite images to determine land-cover types at the two locations and calculated indices of habitat fragmentation. For genetic analyses, we extracted DNA from the leaf tissue of individuals from the two subpopulations and used 11 microsatellite markers to genotype them. We calculated heterozygosity, allelic richness and the F-statistics, to evaluate genetic variability. The montane rainforest in Topes de Collantes was most affected by habitat fragmentation, with smaller patches of more irregular shapes, compared to submontane forest at this location and both montane and submontane forests in Lomas de Banao. Genetic diversity was higher in Topes de Collantes, but we found no genetic differentiation between subpopulations. Our findings suggest the two subpopulations can be considered a single evolutionary unit and conservation entity. We propose to use individuals from both subpopulations for reinforcement to increase the overall genetic diversity of the subspecies.[ABSTRACT FROM AUTHOR]