Caracterización florística y estructura de un parche de bmh-PM, en la quebrada Agua Blanca, Yopal, Casanare

Abstract

The floristic and structural characterization of the woody vegetation was made in a fragment of very humid premontane forest (bmh-PM) of 130 ha, located in the upper part of the Agua Blanca stream (Cravo sur watershed), Marroquín-Yopal, Casanare department; within which there have been sightings of individuals of Ateles belzebuth É. Geoffryoy (Spider Monkey) known by the inhabitants of the region as "Zambo", a species that according to the IUCN (2008) is within the primate species in threat category EN (Endangered). Six permanent vegetation plots of 0.1 ha each (20x50 m) were established; Within which data were taken from individuals with reference diameter (DBH) greater than or equal to 2.5 cm (Gentry, 1988). The majority of the registered individuals were latizales (890), followed by fustales (345) and in smaller proportion bushes, lianas and palms. A total of 60 botanical families represented in 117 genera and 173 species were found. The most representative families were Lauraceae (6g-20sp); Leguminosae (6g-11sp), Rubiaceae (9g-10sp), Sapindaceae (6g-8sp), Annonaceae (4g-7sp), Moraceae and Euphorbiaceae (4g-7sp), and Melastomataceae and Myrtaceae (3g-7sp). The families with the highest Importance Value Index (IVI) were Rubiaceae (16.3%), Sapindaceae (8.1), Euphorbiaceae (6.5%), Meliaceae (5.6%) and Lauraceae (5.3%). The five most important species at the ecological level (IVI) were Simira cf. cordifolia (6.74%), Pogonopus cf. tubulosus (4.32%), Matayba cf. guianensis (4.14%), Trichilia cf. pleeana (3.93%) and Simira cf. maxonii (3.67%). Taking into account the species accumulation curve and the non-parametric Chao 1 and ACE estimators, which take into account the rare species, the sampling efficiency was high (82.77% with Chao 1 and 84.58% with ACE) and the variability of the study area was largely covered. According to the obtained Ogawa diagrams, an absence of defined strata is detected for the forest patch of the study area, on the contrary, there is usually a formation in comet tail relatively defined in the 6 plots; which indicates that the study area is apparently a heterogeneous and mature forest ecosystem. The diametric distribution showed a characteristic behavior of inverted J associated with forests with significant levels of maturity characteristic of heterogeneous forest ecosystems or with a high tendency to heterogeneity (Melo, 2000, cited by Melo & Vargas, 2003). The study area presents in general significant levels of richness and diversity, however, depending on the diversity index, it differs to a greater or lesser extent with those obtained in studies of areas with the same or similar life zone; The foregoing can be explained by the levels of anthropic and natural disturbance that occurred in the past in the study area. The present study is given within the framework of the conservation strategy of the Spider Monkey (A. belzebuth) and the forest of the Aguablanca micro-watershed, "Una casa para Zambo"; implemented by the Asociación de Becarios del Casanare (ABC).