Reduced damage and epiphyll cover of leaves ofKorthalsiarattans that hostCamponotusants in the rain forest of Malaysian Borneo

Abstract

Abstract:Many species of palm produce chambers called domatia that are used by ants as nesting spaces. However, the ecological nature of this association is not well understood, and the information on palm–ant interactions is primarily anecdotal. Here, we conducted a field study in the secondary forest of the Danum Valley Conservation Area, Malaysian Borneo, on 41 individuals of the rattanKorthalsia furtadoana. All studied plants showed signs of a past or present partnership with domatia-nesting ants, as indicated by entry holes in domatia. In 14 plants, our physical disturbance of a stem provoked the appearance of patrolling ants ofCamponotussp. We compared the leaf conditions of rattans with and without patrolling ants, testing whether the presence of ants is linked to improved leaf health. The leaflets of plants with patrolling ants were significantly less physically damaged and less covered by epiphylls. On average, 19% of the leaflets of plants with patrolling ants were damaged (52% in plants without patrolling ants), and the epiphyll cover of their leaflets was 0.2 on our scale of 0–4 (1.3 in plants without patrolling ants). Our results suggest that this poorly studied plant–ant association has a mutualistic character. It seems that the ants take advantage of the nesting space created by the plant partner, while the plants gain protection for their photosynthetic apparatus against herbivores and epiphylls.