Introducing the bipartite Package: Analysing Ecological Networks

Interactions among species in ecological communities have long fascinated ecologists. Prominent recent examples include pollination webs (Memmott et al., 2004), species-rich predator-prey systems (Tylianakis et al., 2007) and seed dispersal mutualisms (all reviewed in Bluthgen et al., 2007). Many of the topological descriptors used in food webs since the 1960s have limited ecological meaning when only two trophic levels are investigated (for example chain length: Pimm, 1982/2002; Montoya et al., 2006). Here, the network becomes bipartite, i.e. every member of one trophic level is only connected to members of the other trophic level: direct interactions within trophic levels are regarded as unimportant. For…