Environmental Engineering Reference
In-Depth Information
20 km
Extinct
Persist
Expand
Fig. 11.4 Results of a bioclimatic model for the plant Protea lacticolor in the Cape Floristic
Region of South Africa. Its current distribution is represented by red and green squares on
the map. According to the modeled climate change scenario, the species is predicted to
persist in the green areas in 2050 but will be extinct in the red areas, because here the
future patterns of temperature and water availability will be beyond the plant's climatic
envelope. Blue squares represent new areas that could be inhabited by the plant provided
their dispersal capabilities (or action by conservation managers) can get them there. (From
Hannah et al., 2005.) (This fi gure also reproduced as color plate 11.4.)
11.2 Climate change
predictions based
on the ecology of
individual organisms
Mirroring the logical organization of Chapters 2-4, in this section I present exam-
ples of climate change predictions that rely on theories of the niche, life history and
dispersal.
11.2.1 Niche theory
and conservation -
what a shame
mountains are
conical
A remarkably diverse vegetation type occurs around South Africa's Cape of Good
Hope. The 'fynbos' is characterized in particular by Protea species such as the one
shown in Figure 11.4, signifi cant both from a biodiversity point of view and because
of their economic importance in the fl oral trade. Extinction risk as a result of habitat
loss is already high in the Cape Region, and global climate change makes the fate
of many of the species even more precarious. Bioclimatic niche modeling is feasible
for these species because their distributions are well studied, fi ne-scaled current
bioclimatic data are available (together with other important environmental data
such as soil type) and future climate modeling is in an advanced state.
Figure 11.4 illustrates how individual species can be expected to make both gains
and losses in habitable area so that, in theory, the effect of climate change might be
neutral. However, such a benign outcome is not very likely where suitable habitat
has been reduced and fragmented by land-use development. A crucial question then
is whether or not future habitat substantially overlaps with nature reserves. In
Search WWH ::




Custom Search