|| 要旨トップ | 本企画の概要 |||日本生態学会第57回全国大会 (2010年3月，東京) 講演要旨|
Myrmecophytes are defined as plants that have symbioses with ants by providing nest spaces for the ants. Generally, the symbiotic ants protect the myrmecophytes from attacks by herbivores. Thus, the interactions between myrmecophyte and their symbiotic ants are usually mutualistic. Macaranga is a plant genus that includes more than 20 species of myrmecophytes. The myrmecophytes in this genus provide their symbiont ants with food as well as nest space. Several Macaranga myrmecophytes often coexist in the lowland of Bornean tropical rainforest area. Myrmecophytic traits are known to vary among coexisting species of Macaranga myrmecophytes (Itioka et al. 2000, Nomura et al. 2000 etc.). However, effects of the interspecific variation on the diversity of herbivores and those on the characteristics of the interactions in the community around the Macaranga myrmecophytes have not sufficiently investigated. In this paper, we will show advance in our investigations on the effects. Our results suggest that the variation in the balance between anti-herbivore defenses by ants and those by the other mechanisms (chemical and physical ones) among Macaranga myrmecophytes affects the difference in the species compositions among them. Effects of ontogenetic change in myrmecophytic traits on the herbivores will be discussed as well.