The endemic New Zealand mistletoe Fuchsia persuades, which has ornithophilous flowers, may be prone to pollinator limitation on the New Zealand mainland where pollinating birds are often scarce. To investigate this possibility, we hand-pollinated flowers on plants at two sites on the Banks Peninsula and compared their reproductive success with unmanipulated flowers on the same plants. In the 1999 season at Buckleys Bay, fruit initiation was 3.3 times higher on hand-pollinated flowers (66.6% of flowers) than unmanipulated flowers (20.0%), and fruit set was 2.7 times higher (47.9% versus 18.0%, respectively). In developed fruit, seed set per fruit was higher for hand-pollinated (70.9% of ovules) than unmanipulated flowers (48.0%). The results indicate that 34% of ovules from hand-pollinated flowers, but 9% of ovules from unmanipulated flowers, set seed. Germination rates did not vary significantly among treatments. In the 2000 season, at both sites, fruit set of hand-pollinated flowers was at least 1.7 times higher than unmanipulated flowers (P = 0.028), and the fruit set of unmanipulated flowers did not differ significantly from that of bagged flowers from which all pollinators were excluded (P = 0.98). These results agree with other studies of ornithophilous plants on the New Zealand mainland and suggest that pollinator limitation is a frequent consequence of the rarity of honeyeater birds.
Pollinator limitation of seed set in Fuchsia Perscandens (Onagraceae) on Banks Peninsula, south Island, New Zealand
Year: 2010
