Epilithic diatoms (Bacillariophyta) from cloud forest and alpine streams in Bolivia, South America II: A preliminary report on the diatoms from Sorata, Department of La Paz

Abstract

Un total de siete muestras de epiliton fueron colectadas en ríos dentro de un gradiente altitudinal en el bosque nublado de Bolivia, cerca de la capital La Paz. La flora diatomológica es diversa y no se encontraron patrones altitudinales claros. Tal flora está compuesta por especies cosmopolitas y taxa restringidos a los Andes con los géneros Gomphonema, Nitzschia, Encyonopsis y Encyonema agrupando al mayor número de especies e individuos con mayores frecuencias. La flora está también representada por varios taxa alcalifilos y alcalibiontes, reflejando los altos valores de pH de los ríos. Las características de los sitios muestreados, así como una lista de taxa y figuras representativas se presentan en este trabajo.A total of seven epilithic samples were collected from streams along an altitudinal gradient within the Bolivian Cloud Forest region near the capital La Paz. The diatom flora is diverse and no clear altitudinal trends were found. The flora is composed of cosmopolitan species and taxa restricted in distribution to the Andes with the genera Gomphonema, Nitzschia, Encyonopsis, and Encyonema containing the greatest number of species and individuals with higher frequencies in samples. Diatoms from this region are also represented by several alkaliphilous and alkalibiont taxa reflecting the high pH of the streams. General characteristics of the sampled sites as well as a list of taxa and figures of representative taxa are presented herein.