Effect of the ant species complex on diaspore removal

Abstract

Diaspores of myrmecochorous plants are usually removed not by one but rather several different ant species. A. Beattie (1983) provided a list of 80 ant taxa, which were registered in the literature as seed dispersal agents. Ant individuals of the same species usually remove diaspores of different plant species at various rates, depending on the diaspore size and other characteristics of the myrmecochorous syndrome, as well as on the size of the ant individuals (Culver and Beattie, 1980; Nesom, 1981; Clay, 1983; Wein and Pickett, 1989; Higashi et al., 1989; Gorb and Gorb, 1995a; b; Gorb, 1998). Ant species can have different life histories and behaviour, which may influence diaspore removal rates, seed flow on ant territories, and seed concentration within ant nests to a different extent. Furthermore, foraging behaviour of the same ant species may change depending on the presence of other species in the ecosystem. It is suggested here that not just one species but rather it is myrmecocomplexes that have an effect on diaspore dispersal and on the distribution of seedlings. Such myrmecocomplexes also influence plant species complexes in the ecosystem. In this chapter, experimental results of seed removal of the violet Viola odorata by four ant species in three forest microsites, differing in ant species composition, are presented.