the mechanism of competition, or the competitive
hierarchy among these species, is not so easy. The
other important feature that is missing from most
food webs is the network of mutualistic interactions,
such as those described in Chapters 2 and 13. Here,
the inclusion of mutualistically linked species is rela-
tively straightforward, as is the possibility that mu-
tualists may compete with one another, or may
consume or be consumed by other species. The
main limitation is that for most networks we have
relatively little information about the structure of
competitive or mutualistic interactions.
Once these more interactively complete ecological
networks have been realized, we can begin to ask
fundamental questions about their topology and
functional attributes that we currently cannot do
with the fragmented information that we have
about networks of predators and prey, competitors
and mutualists. As a first pass, it would be interesting
to evaluate the relative frequency of consumer, com-
petition and mutualistic links in webs, to assess the
potential relative importance of these different inter-
actions in networks of different provenance. Similar-
ly, the relative contribution of links/interactions of
different sorts to overall community stability could
be inferred by modelling their respective impacts on
inferred network stability. There may also be inter-
esting differences in those portions of total interac-
tive connectance associated with three fundamental
kinds of interspecific interactions. These are ideas
that we can only begin to explore as we obtain more
complete information about the range of interactions
that occur across a broad range of communities. It
also behooves ecologists not to focus exclusively on
the topology of these systems, as the real goal here is
to explore the extent to which interactions confer
structure on the many kinds of communities that
fascinate us (Ingset al. 2009).EMERGING FRONTIERS OF COMMUNITY ECOLOGY 201