Dealing with global climate change - Ecological Applications: Toward a Sustainable World - page 325

also modify the interactions among species that infl uence the course of succession.
And fi nally, climate change is predicted to affect successional end points or, in other
words, the characteristic biome of the area in question.
Climate change may affect particular species and these, because of their commu-
nity role, can produce ramifi cations that spread through the food web. Some species
are more vulnerable because they are affected both directly by climate change and
indirectly through interactions with their prey, predators or mutualists (which
themselves will be infl uenced in diverse ways by climate change). The predicted
spread of human disease will sometimes depend on the consequences of climate
change for the distribution of insects that act as disease vectors.
Climate change can also be expected to impact on a variety of ecosystem services,
including the provision of suffi cient water, productive soils, fl ood control and rec-
reational opportunities such as skiing.

Climate change predictions based on landscape ecology
When considering the effects of climate change, a landscape perspective is generally
appropriate because managers need to envision how global climate change will
reorganize regional landscapes. A prediction based on island biogeography theory
is that smaller areas contain fewer species. Extinction risk of endemic species due
to climate change can be estimated in terms of loss in area of key habitats. A large
proportion of the world's biota seems at risk but suitable choice of protected areas
can minimize the predicted losses. In some cases, current nature reserves will prove
to be in the wrong places - climate change models can assist managers to plan future
reserve networks.

The fi nal word

Valerie the anthropologist can see the parallels between human populations losing
their habitat on low-lying Pacifi c islands and the many examples where the distribu-
tions of plants and animals are predicted to change. ' It occurred to me that the average
effects of global climate change might, in theory, be neutral - with some species benefi ting
and others losing out. But this isn't the case for biodiversity, is it? With global warming
the ranges of species must generally shift towards the poles and up in elevation. And
doesn't this mean that species ranges will tend to contract into smaller areas, with con-
sequent losses to biodiversity? '
Imagine the world is faced by global cooling rather than global warming. Outline
the patterns of change that you would expect in species ranges, biodiversity, har-
vests, human disease and pest control under a global cooling, as opposed to global
warming, scenario.

References

Barlein, F. & Huppop, O. (2004) Migratory fuelling and global climate change. Advances in
Ecological Research 35, 33-47.
Beaumont, L.J. & Hughes, L. (2002) Potential changes in the distributions of latitudinally
restricted Australian butterfl y species in response to climate change. Global Change Biology
8, 954-971.
Begon, M., Townsend, C.R. & Harper, J.L. (2006) Ecology: from individuals to ecosystems , 4th
edn. Blackwell Publishing, Oxford.
Bryden, H.L., Longworth, H.R. & Cunningham, S.A. (2005) Slowing of the Atlantic meridi-
onal overturning circulation at 25˚N. Nature 438, 655-657.