COMMERCIAL PICKING OF BANKSIA-HOOKERIANA IN THE WILD REDUCES SUBSEQUENT SHOOT, FLOWER AND SEED PRODUCTION

1. The impact of bloom picking on subsequent flower and cone productio n, seed bank dynamics and plant architecture was studied in three pick ed and three unpicked 13-year-old populations of Banksia hookeriana, a canopy seed-storing, fire-sensitive shrub, growing on infertile sands in dry-mediterranean scrub-heath near Eneabba, Western Australia. 2. Since reaching reproductive maturity at 4 years, bloom picking over th e subsequent 9 years reduced plant canopy area and volume by 37% and 4 4% respectively, with a 56% reduction in the number of 1-year-old stem s, compared with the unpicked plants. 3. A total of 13255 blooms ha-1 was picked over the 9 years, accounting for 29% of total production. C ockatoos removed a further 2477 blooms ha-1 (5% of the total), but rem oved over 3 times as many blooms in the unpicked plants (7562 ha-1, 7% of the total). 4. Resprouting was much more likely from cockatoo-dama ged stems than from picked stems. 5. Picked plants produced 35% fewer blooms than unpicked plants, but percentage cone fertility and the num ber of follicles per fertile cone did not differ significantly. 6. See d production and storage per individual plant were 50% and 57% lower r espectively in the picked plants. 7. There was a slight increase in to tal insect-eaten seeds (4%), and a slight decrease in viable seeds (9% ), in picked plants; but there were no significant differences in the fractions of seeds released, aborted or non-viable. 8. The reduced see d store following picking could adversely affect post-fire regeneratio n, particularly if fires were at short intervals followed by an unusua lly severe summer drought. 9. The study shows the usefulness of demogr aphic studies in guiding management to resolve the conflict between co mmercial exploitation and the conservation of rare plant species.