FRUIT PRODUCTION BY ACACIA-ALBIDA TREES IN ZAMBEZI RIVERINE WOODLANDS

Fruit production by Acacia albida (Leguminosae: Mimosoideae) trees in Mana Pools National Park, Zimbabwe, was monitored over eight years. Timing of ripe fruit-fall varied between years, as did fruit production: production of ripe fruits by the same tree varied from 5.4 kg in 1983 to 290.1 kg in 1988. Baboons reduced fruit production by feeding on unripe fruits and the mass eaten each year was negatively correlated with rainfall. Potential fruit production (i.e. production in the absence of baboons) was high when the late wet season was wet or cool and when fruit production in the previous year was low. Late wet season rainfall and temperature probably determined the degree of defoliation by caterpillars: in 1983 and 1987, when the late wet season was hot and dry, the trees were almost completely defoliated. During the late dry season, A. albida fruits were an important component of the diets of waterbuck, eland, elephant, buffalo and kudu; they were seldom eaten by hippopotamus and were ignored by zebra and warthog.