FRUIT AND SEED PRODUCTION IN BERBERIS-DARWINII HOOK, A SHRUB RECENTLY NATURALIZED IN NEW-ZEALAND

The fate of Berberis darwinii flowers and fruit was recorded in 1987 and 1989 near Dunedin, southern New Zealand, and seed germination was tested experimentally. Flower and fruit production were reduced by abortion of both whole inflorescences and individual flowers and fruit, by goat browsing, and by insect damage. Mature flower survival to produce ripe fruit (55% in 1987 and 44% in 1989) was high in relation to most species with similar reproductive ecology but growing within their natural range, as were the proportion of ripe fruit taken by birds (74%, 77%), ripe fruit production (> 4000/m2 of canopy projection) and seed germination rate (94%). Seed production and dispersal were subject to few constraints, as has also been shown of other naturalised woody species.