Ecological suitability and tree seedling survival in the Bolivian altiplano

Abstract

Tree seedling survival rates are low in the dry, harsh climate of the Bolivian altiplano. We tested two species, Polylepsis tarapacana and Cupressus macrocarpa, using four microcatchment planting methods and a control to determine if species survival could be improved. The control improved surface infiltration rates but provided no protection from wind and cold. The four sub-surface planting methods increased soil moisture and mitigated cold, desiccating winds. The native species, P. tarapacana, showed better survival than the non-native one. All planting methods showed excellent survival rates for P. tarapacana, as all methods improve rainfall infiltration in relatively poor soil. Pit planting proved to be more successful for C. macrocarpa than other planting methods, probably due to the protection it provides from climatic stress during the winter months and the increased soil moisture. While modifying the local micro-ecological conditions improves seedling survival, selecting ecologically suitable species is a more successful strategy for tree planting.