One main message of community ecology to its
applied end-users and stakeholders is that many
local problems can have remote causes. Whether
this concerns local overgrazing, aboveground
pests or biological invasions, the problems quite
often originate at a different place from where the
problems occur. Community ecology could pro-
vide help in solving these applied problems by
analysis of the complex interactions in which
many species are involved. In some cases, such as
ecosystem restoration, original key interactions
need to be determined and the key players need
to be brought into contact. Restoration ecology still
makes very little use of community ecological in-
sights, except the use of large herbivores. Major
omissions concern the involvement of inverte-
brates, of soil communities and of interactions of
plant communities with above- and belowground
organisms.
Biological invasions are a global problem. In-
creasing globalization of the economy, international
tourism and enhanced emigration–immigration en-
sure that more and more non-native species will
move to novel areas where they could become in-
vasive. Predictive systems are necessary to forecast
whether certain species have the potential to be-
come invasive in their new habitat and, when so,
to identify these species for import limitation. The
main problem is twofold. First, only a minor frac-
tion of all introduced species become invasive, so
that the predictions need to detect0.1% of all
species as possible invaders. Usually, this is a
range where statistics are uncertain. Second, the
current rapid climate warming may change local
conditions to become favourable for new intro-
duced exotic species. This, together with range
shifts due to climate warming, may elevate the
future incidence of biological invasions. Especially
when range shifts release plant species from below-
ground (van Grunsvenet al. 2007) or belowground
and aboveground enemy attack (Engelkeset al.
2008). The same has been shown for higher trophic
level interactions, such as between insects and their
enemies (Menendez et al. 2008). These future
changes will require considerable attention from
community ecologists.
The most striking examples of remote causes for
local problems are definitely those where species
move over large distances, such as the geese that
migrate from mid-west USA to the Arctic zone. To
solve these and to prevent other problems, it is
crucial to thoroughly analyse all consequences so
as to not create additional problems while attempt-
ing to solve an initial one. Community ecology
should be at the forefront in these analyses, given
the complexities involved. Interestingly, these ap-
plied questions could also be used as learning op-
portunities, because the shortcomings of the
predictions will reveal the limits of our knowledge.
Therefore, community ecologists should take an
active role in analysing causes of environmental
and biotic change and in forecasting consequences
of new policy and management strategies. The
challenge is huge, and includes biobased economy,
biofuels, sustainable agriculture, biodiversity
restoration and conservation, climate warming,
and the consequences of genetically modified
organisms.APPLICATIONS OF COMMUNITY ECOLOGY APPROACHES 93