Regeneración de árboles en ecosistemas naturales y plantaciones de pinus patula (Pinaceae) dentro de un gradiente altitudinal andino (Azuay, Ecuador)

Andean forests and paramo have high species richness, but constantly they are threatened by deforestation. Natural arboreal regeneration of these ecosystems will conditiotheir structure and functionality in the future, but now it has been poorly evaluated. In the Andes of SoutherEcuador, there are also abandoned Pinus patula (pine) forest plantations, which could be scenarios to promotnatural regeneration. In an Andean altitudinal gradient, we evaluated floristically parameters of tree regeneratiobetween two study scenarios: natural ecosystems (herbaceous paramos and natural forests) and pine plantationFor this, the diversity of regeneration was described by species richness, Shannon index and floristic compostion. Abundance with the number of individuals; these parameters were compared between two scenarios. Wdetermined also that environmental variables or predictors of: canopy cover, soil, tree structure, horizontal distance and physiographic explained the variation in the parameters of regeneration with greater magnitude. Fothis, a partition analysis of the variation was carried out. Richness and diversity of species were greater in naturaecosystems, whereas floristic composition was different and its abundance was similar. In natural ecosystembasal area and tree density explained mainly the variation in wealth, diversity and abundance. Not so in pinplantations where horizontal distance to the native forests was the predictor that mostly explained. The greatesdiversity of regeneration in natural ecosystems (forests) is associated with the existence of arboreal, shrub anseed biotypes. It is adding to this, efficiency in dispersion processes at the micro-habitat level. These aspectare limiting in plantations of pine, in which the dispersion or availability of seeds depends on the proximity tnatural ecosystems.