Efecto de la altitud y el micrositio sobre plántulas reforestadas de Polylepis lanata (Rosaceae) en el noroeste de Cochabamba, Bolivia: implicaciones para su restauración ecológica

Abstract

The reforestation of Polylepis lanata (Rosaceae) seedlings is limited by the poor knowledge about the environmental conditions that needs to survive and grow. The objective of the study was to determine how altitude and microsite affect seedlings survival and growth. An experiment was implemented with seedlings gathered from the forest and planted on 15 plots distributed in five altitudes (2,690–3,900 m; three replicates per altitude). In each plot, seedlings were planted in heterogeneous microsites. The study was carried out in the community Pajchanti in Northwestern Cochabamba, Bolivia. Survival and growth were assessed 14 and 51 months after planting. We measured altitude of plots and microsites around of each plant (cover shrubs, stones, moss, herbs, grassland, depth of humus and slope). The data analysis was conducted through the fit of generalized linear models, model selection and inference multi-model based in Akaike Information Criteria. The altitude and shrub cover had a positive effect on seedlings increasing their probability of survival; both were the most important variables. The humus, cover of stones and shrubs around the seedlings also improved the growth rates. The reforestations should be carried out in middle altitudes, 3,000 to 3,600 m, but in safe microsites which protect to the seedlings from a possible environmental stress outside of the forest, due to human disturbance of soil and vegetation.