Influencia del micrositio y el ambiente en la instalación de Polylepis tarapacana en los Altos Andes

Abstract

Of the total numbers of microsites present in an environment, only a fraction presents adequate conditions to ensure the regeneration of the forest. This study analyzes the facilitation given by the environment and the microsites in the P. tarapacana regeneration in the High Andes. We worked with 21 forests in Jujuy, Argentina, registering variables of forest structure, soil moisture and the offer of microsites. Pearson correlation analyses were done between environmental variables and forest structure of seedling and trees and shrubs. In addition, a simple ANOVA were performed using 8 categories of microsites as the main factor to analyze soil moisture and the density of seedling. The density of seedling represents 36.8% of the density of trees and shrubs. At greater slopes, the presence of seedling decreases, but no significant differences were found with altitude. A higher seedling density (201.2 and 279.5 ind. ha −1 ) was found in microsites under the influence of rocks that coincide with higher soil moisture, but not in microsites with litter, with the same moisture content. There was a varied offer of microsites that could be found in the study area, where the density of the seedling was positively related to the offer of microsites under the influence of rocks and was associated with their relative humidity. These results define microsites favorable for regenerating P. tarapacana which can be used to identify the most suitable areas for restoration and preservation of this species. RESUMEN

Characterization of Polylepis tarapacana Life Forms in the Highest-Elevation Altiplano in South America: Influence of the Topography, Climate and Human Uses

“…Moderate to steep slopes are environments where this species presents its greatest development [19,23], because these landscapes provide safe and suitable sites for seed survival, germination and development of individuals, provided by, among other factors, the higher soil moisture and proportion of daytime with shade offered by rocks that reduce soil evaporation, as well as the smaller temperature fluctuations moderating competition for water with herbaceous vegetation [69]. We observed that the frequency of Ar decreases with the slope, while the Bt form increases its frequency considerably, mainly due to the instability of the soil, which produces the banded shape for this species, and the damages caused by this movement of gravel and soil reduces the frequency of Ar forms.…”