Increased thorn length in Acacia depranolobium- an induced response to browsing

Summary. I report here longer thorns induced by large mammal herbivory on the tree Acacia depranolobium. I compared trees that had been browsed by domestic goats to trees protected from goat browsing. Thorns on browsed branches within the reach of goats (<125 cm above the ground) were significantly longer than thorns from higher branches on the same browsed trees, and significantly longer than branches at similar heights on unbrowsed trees. It appears that increased thorn length was an induced re-sponse to large mammal herbivory in Acacia depranolob-ium, both among and within individuai trees. Key words: Induced defense- Herbivory A growing body of descriptive and experimental evidence indicates that individual plants subjected to herbivory in-crease their defenses. Induced resistance to insect attac