Influence of tree species and compass bearing on insect folivory of nine common tree species in the West African savanna

Abstract

Levels of leaf damage due to insect folivory have been investigated in forests of different latitudes all over the world, but most research has concentrated on a few common forest types. Most studies of insect herbivory were conducted in (sub)tropical rain forests (Barone 1998, Basset 1996, Coley 1983, Lowman 1985), or in temperate forests (Landsberg & Ohmart 1989, Lowman & Heatwole 1992). In contrast, little is known about insect folivory of woody plants in tropical savannas (Fowler & Duarte 1991, Marquis et al. 2001, Ribeiro 2003, Stanton 1975), and no such data are available for the West African savanna ecosystem (Andersen & Lonsdale 1990). Savannas cover about 40% of the land surface of Africa and 20% of the world (Scholes & Walker 1993), and savanna trees may host considerable numbers of insects, including many herbivores (Grant & Moran 1986, Mody et al. 2003). Therefore, insect herbivory can be considered a potentially important aspect of plant–animal interactions for vast areas of tropical ecosystems, where it has been studied remarkably rarely so far.