CHAPTER 5
Increasing spatio-temporal scales:
metacommunity ecology
Jonathan M. Chase and Janne Bengtsson
5.1 Introduction
Community ecology is a dynamic and rapidly
changing field. While community ecology in the
1980s and 1990s focused primarily on how local
environmental conditions, and species interac-
tions within those localities, influenced patterns
of coexistence and relative species abundances at
the local scale, more recent years have seen an
increasing recognition (or rediscovery) of the im-
portant role of space and time (Ricklefs 1987, 2004;
Ricklefs and Schluter 1993; Hubbell 2001; Leibold
et al. 2004; Holyoaket al. 2005). We refer to the
implicit recognition (and study) of the important
role of spatio-temporal dynamics as metacommu-
nity ecology.
By analogy with a metapopulation, which refers
to a series of populations interconnected by dis-
persal among patches, a metacommunity refers to
a collection of communities of potentially interact-
ing species that are interconnected by dispersal
(Leiboldet al. 2004; Holyoaket al.2005).Accord-
ingly, the simplest model of a metacommunity is
one of several non-interacting species each exist-
ing in co-occurring metapopulations. In practice,
however, the symmetry between metapopulations
and metacommunities is loose at best. Although
population biologists often make great efforts to
define the scope of a metapopulation, the scales
under consideration can be highly variable within
the context of metacommunities. Spatial scales can
range from small-scale environmental gradients or
patches in which species colonize or go extinct, to
large-scale biogeographic studies across provinces
and continents. Furthermore, temporal scales
under consideration within the metacommunity
context range from seasonal or yearly fluctuations
to eons of global climate change and phylogenetic
inertia. Individual species in a metacommunity
respond to scale differentially. Finally, among spe-
cies in a metacommunity, there are often large
differences in movements and dispersal, and
rates of reproduction and mortality, which depend
on several factors, including behaviour, body size
and trophic level. Thus, rather than trying to de-
fine the range of a metacommunity, we instead
focus on the concept of metacommunities as incor-
porating aspects of community ecology at larger
spatio-temporal scales. These can range from as
small a scale as considering the variation of plant
species that occur on different aspects of a hillside
slope to as large a scale as considering the varia-
tion in plant species composition across biogeo-
graphic provinces. When setting out to test a
given metacommunity model, it is important to
recognize the constraints on those models, and to
address their predictions at appropriate spatio-
temporal scales. It would, for example, be rather
silly to test the predictive ability of a ‘mass effects’
metacommunity model, which inherently assumes
spatially heterogeneous environments (e.g. Mou-
quet and Loreau 2003), at a scale so small that the
landscape is essentially homogeneous.
Throughout this chapter, we will intermingle dis-
cussions of more historical perspectives of meta-
community ecology into the contemporary
perspective. We do this because we feel that in57