Introduction How do so many species coexist in nature? This long-lasting question in ecology (Hutchinson, 1959) was given a new direction by the theoretical prediction, derived using a mathematical model of random communities, that a more complex community network, characterized by higher species richness or more interspecific interactions, is less likely to be stable (May, 1972). The major issue that arose was why a complex community, which should be unstable according to ecological theory, can persist in real nature. An approach that has commonly been taken to tackle the issue was to change the assumption of random community (Lawlor, 1978). This approach seems to have been successful to some extent. Indeed, recent studies that looked into the real community network have identified structural non-randomness of community networks that can help the persistence of species in a community (Neutel et al., 2002; Emmerson and Raffaelli, 2004; Kondoh, 2008; Thébault and Fontaine, 2010; Stouffer and Bascompte, 2011). A number of studies were carried out to describe the detailed structure of real community networks, such as food web (de Ruiter et al., 2005) and mutualistic web (Bascompte and Jordano, 2013), and to find their structural patterns that may contribute to community stability. It is no doubt that analysis of those specific networks greatly contributed to our understanding of how ecological communities are organized and how their structure is related to community dynamics. However, at the same time, little is understood regarding the structural and dynamics properties of community networks with multiple interaction types. Actually, it is only recently that different interaction types have been put together in a single picture describing how diverse species and variety of interactions are built up into a complex network of ecological community (Ohgushi, 2005; Mélian et al., 2009; Thébault and Fontaine, 2010; Kéfi et al., 2012; Pocock et al., 2012; Toju et al., 2014). While a number of studies have been carried out to understand how species diversity contributes to population, community dynamics, and ecosystem processes (e.g., May, 1972; Hooper et al., 2005), it is only recently that the ecological consequence of interaction diversity has been theoretically explored (Allesina and Tang, 2012; Mougi and Kondoh, 2012, 2014a, b, c; Georgelin and Loeuille, 2014; Sanders et al., 2014; Rúa and Umbanhowar, 2015).
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Environmental Science(all)