Abstract

Reproductive success (flowering, seeding and seedling) is a paramount process for tree regeneration and forest ecosystem conservation and management. In mixed forests, the impact of limiting (biotic and abiotic) factors on tree reproductive success regulates themaintenance of species in balanced proportions, or the conversion towards monospecific forests. We assessed tree reproductive phenology andsuccess in pure deciduous Notofagus pumilio (Np), pure evergreen Nothofagus betuloides (Nb), and compared it with mixed (M) forests,considering two geographical location (coast and mountain), during three years. Also we evaluated the incidence of different loss factors (e.g.,premature abortion, fruit and seed predation). Both deciduous and evergreen species have reproductive advantages in M compared to pureforests: (i) less abortions (flowers and fruits) of Nb in M than in pure forests (ii) M had twice male flowers of Nb than in the pure forests. Seedproduction was highly variable for both tree species in all sites. However, M was more similar to pure evergreen forests in their reproductive traits(e.g., amount of seed fall) as the potential seed production (number of possible propagules including lost structures) was more similar betweenNb and M. The main limiting factor was female flowers deriving in empty seeds for all forest types. We detected a strong effect of geographicallocation on seed production as well as on the losses factors during flowering and seeding stages. However, Np was less responsive togeographical locations, while the marine climate seems to be more favourable for Nb. This study contributes to understanding of the possibleroles of reproductive phenology for detecting shifts in forest communities between pure and mixed forests under natural dynamics and thecurrent climate regime.