Extensive pollen flow may counteract the effects of landscape fragmentation

MARCHELLI, P; MORENO, C; GALLO, L A

Bariloche, Argentina

Workshop; Understanding Biodiversity Loss: A Workshop on Forest Fragmentation in South America; 2006

IALE

Pollen flow might constitute a fundamental factor in balancing some of the negativeeffects of forest fragmentation. Wind pollinated species in Patagonia can overcomethe isolation of populations by mechanisms of extensive pollen flow favored by thestrong directional winds of the region.Several species of Patagonia have passed through a fragmentation process. Inorder to evaluate the degree of connectivity between populations and therefore theeffect of fragmentation, pollen flow studies are being conducted in Nothofagusnervosa, Austrocedrus chilensis and Araucaria araucana.In N. nervosa, we began with an intrapopulation pollen flow study in order toestablish the pollen dispersal curve (and the effective pollination distance). Wecollected buds and seeds from 25 mother trees and we are analysing between 10 to20 seedlings per mother. For A. chilensis and A. araucana we have recently beguna project in order to study pollen flow in fragmented populations in the steppe. Forthat purpose we have sampled mothers and seeds from different locations with aspatially explicit design (total of 140 mothers and 30 seeds/ mother). We areanalyzing the material with microsatellites markers and applying the TWOGENERmethod.Preliminary results, problems and perspectives of both studies are presented anddiscussed.