Caracterización de elementos xilemáticos de conducción de 40 especies de El Dorado-Santa Elena de Uairén (Estado Bolívar, Venezuela)

Abstract

A study of xylematic conductive elements of 40 species in tropical wet forest and tropical premontane wet forest from El Dorado-Santa Elena de Uairen (Bolivar state, Venezuela), is presented. Histological slides and macerated tissue were prepared according xylematic microtechnique standards. Studied features were porosity, perforation plates type, intervessel pits type and size, vessel frecuency, vessel tangential diameter, vessel elements length, tracheids (vascular or vasicentric) presence and perforated ray cells presence. Vessel grouping, vulnerability and mesomorphy indexes are calculated. Results are compared with previous reports for other life zones in Venezuela. According vulnerability (Iv) and mesomorphic (Im) indexes, species show mesomorphic character. Only three species shows a xeromorphic character with Iv < 1. Species with perforated ray cells have low values in Iv. Comparations with previous reports, according Iv, shows similarities with premontane wet forest from La Mucuy, Merida state.