Estructura poblacional de Tabebuia lepidophylla (Bignoniaceae) en el bosque de pinos sobre arenas cuarcíticas de la Reserva Ecológica Los Pretiles, Pinar del Río, Cuba

The areas characterized by soils derived from quartz rocks are among those that have contributed the most to the endemism of the Cuban flora. In western Cuba sandy-quartzite soils are restricted to few outcrops that support pine forests. Tabebuia lepidophylla is an endemic species of this vegetation, both in plains and heights slate. Particularly in the first, the conditions imposed by the nutrient-poor substrate are critical in the development of populations. In the present study, the population structure of T. lepidophylla in the pine forest on quartzite sands of the Ecological Reserve Los Pretiles is characterized. Twenty plots of 25 m2 were established, 10 parallel to the coastline and 10 were set into the pine forest, to assess the influence of the gradient in the structure of the population. The population is stable with a predominance of individuals in the first two height classes, with lower frequencies to the higher. This structure is an indicator of the optimal condition of the population and of its capacity to sustain itself. The density values varied between areas, with higher values far to the coast. The spatial distribution pattern of the population was clustered both at the population level and between areas. The distance to shore conditions and influences the structure of the individuals of the population.