POLLEN DISPERSAL CAPACITY AND POLLEN VIABILITY OF ABIES PINSAPO BOISS

Fresh- and stored-pollen viability, duration of pollen shedding, and p ollen dispersal capacity were studied in a natural Abies pinsapo fores t located in Sierra de Grazalema (southern Spain). Pollen viability in the fertilization period was high (near 100 %) but was lost after 6 m onths storage from shedding. Pollen liberation and seed cone receptivi ty were synchronized within a tree. Total duration of pollen liberatio n in the forest was 1 month, and in a determinate tree was 6 days. Win d-borne pollen density was studied by means of pollen-traps in 2 neigh bouring pinsapo populations with markedly different stand densities. A ir pollen density in open forest was remarkably lower than in closed f orest. Nearness of same pollen-traps (placed in open for est) to close d forest, and the lower pollen quantities recorded in them, could deno te a short-distance pollen dispersal. The results are discussed in rel ation to the high proportion of empty seeds in some pinsapo population s.