Flowering and seeding patterns in primary, secondary and silvopastoral managed Nothofagus antarctica forests in South Patagonia

SOLER ESTEBAN, ROSINA MATILDE; MARTÍNEZ PASTUR, GUILLERMO; LENCINAS, MARIA VANESSA; PERI, PABLO LUIS

New Zealand Journal of Botany

RSNZ PUBLISHING

Lugar: London, UK; Año: 2010 vol. 48 p. 63 - 73

0028-825X

The success of the reproductive process in trees depends on abiotic and biotic factors, that determine the final outcome of the natural regeneration. Silviculture alters biotic and abiotic factors and results in secondary forest structures. To effectively manage these forests, it is necessary to understand the bottlenecks of reproductive stages using a whole cycle approach study. The aim was to analyse flowering and seeding patterns in primary, secondary, and silvopastoral managed Nothofagus antarctica forests, including investigating the pre-dispersion foraging of insects and birds, as well as the abscised biomass production. A high percentage of female flowers produced fruits (95-96%), where the main loss factor before seeding was the abscission of immature fruits (11-14%). Seeding was greater in secondary forests (11.4 million.ha-1), but managed stands presented a higher percentage of flowers resulting in seeds (82%). However, secondary forests had a better seed quality (17% viable seeds), where the main loss factor was empty seeds in all treatments (39-50%). Biotic factors (foraging by insects and birds) were higher in disturbed than primary forests. Nothofagus antarctica produce large quantities of seeds, but abscised immature fruits and empty seeds due to self-incompatibility mechanisms appeared as the major loss factors.