Resumen

GARECA, Edgar E; MARTINEZ, Yvonne Y; SOLIS, Claudia  y  AGUIRRE, Luis F. Effects of exotic trees and maternal environment on seed production, germination and initial growth of Polylepis subtusalbida (Rosaceae) at the Parque Nacional Tunari, Bolivia. Ecol. austral [online]. 2018, vol.28, n.1, suppl.1, pp.262-277. ISSN 1667-782X.

Polylepis subtusalbida's woodlands at the Southern slope of Parque Nacional Tunari (Cochabamba, Bolivia) are key native vegetation remnants between 3200-3900 m.; they provide ecosystem services, specially to the city of Cochabamba. However, these woodlands are highly fragmented and coexist with exotic trees (Pinus radiata and Eucalyptus globulus). This work shows the effects of the exotic trees and the maternal environment on seed production, germination and initial growth of Polylepis. Three se􀄴ings for the exotic trees were studied: Polylepis woodlands a) surrounded by semi-natural grassland, b) surrounded by exotic trees and c) mixed with exotic trees. Fruits from 67 mother trees belonging to seven fragments were used. The percentage of fruits with full seeds was measured as an estimation of seed production. Germination and early growth were evaluated in a common garden with a complete randomized design (germination) and a complete randomized block design (early growth). Variables from the maternal environment were reduced via PCA and backward multiple regression followed by general mixed linear models which were performed to evaluate the effect of the exotic trees, maternal traits and maternal microsite on the seed production, germination and early growth. The percentage of fruits with full seeds diminished as bare soil under the maternal tree increased. Germination was high and it was not affected by the studied factors. Early growth of the progeny was affected by the presence of the exotic trees, bare soil, leaf cover and health of the maternal tree. Seed production was identified as a limiting stage for Polylepis regeneration, and the exotic trees and maternal environment affected early growth of the progeny in a common garden (maternal effects).

Palabras clave : Early growth; Maternal effects; Environmental maternal effects; Microsite; Resource availability; Seed provisioning; Regeneration.