Influencia de variables climáticas, topográficas y edáficas sobre la composición florística, diversidad de especies y densidad en bosques montanos andinos, macizo del Cajas, provincia del Azuay

Abstract

Ecuador has numerous Andean ecosystems among which the native forests stand out. Unfortunately, these natural vegetation ecosystems are threatened by deforestation. Due to the lack of information of these forest ecosystems in the province of Azuay, it is necessary to carry out this work that serves as a starting point to assess these ecosystems regarding their taxonomic diversity. This investigation specifies information in twenty permanent sampling plots located on two altitude floors (Chaucha 2000 to 3000 m. a. s. l and San Gerardo > 3000 m. a. s. l). Here the floristic composition was determined, the diversity was quantified based on the richness and alpha diversity index. The density of the woody vegetation was also quantified and relations between the composition, diversity and density were established with variables of temperature, precipitation, altitude, slope, apparent density, organic matter, pH, texture and electrical conductivity of these Andean forests. As a result, it was determined that the floristic composition and richness was higher at the site of lower altitude (Chaucha) while the density was higher at the site of higher altitude (San Gerardo). Regarding the environmental variables, there were no differences (P <0.05) for slope and apparent density at a depth of 15 cm, nor for pH, nor electrical conductivity at both depths. The soil was characterized as silty loam in Chaucha and as silty loam and sandy loam in San Gerardo. In general, there were correlations between the vegetation variables and the environmental variables studied, thus presenting 9 correlations in woody biotypes ≥ 5 cm of DAP and 8 in biotypes ≥ 10 cm of DAP.