Environmental Engineering Reference
In-Depth Information
FIGURE 5.18 Predicted impact of warming on the performance of animals with body temperatures equili-
brated to ambient (ectothermic or cold-blooded). On both panels the red line is the model output. On the
right panel the dots are the intrinsic growth rates for each insect species examined. On the left panel other
terrestrial ectotherms, including frogs, toads, lizards, and turtles are plotted. Source: Deutsch et al. (2008).
a while at least, will be within the variability of temperatures experienced.
Hence, tropical trees, and other studies will highly likely find the same to
be true for tropical animals and are at higher risk of not being resilient to
the incipient warming (Figure 5.18).
Using the A1B scenario from IPCC (2007a), Wright and co-authors
(2009) found that “75% of the tropical forests present in 2000 will experi-
ence mean annual temperatures in 2100 that are greater than the highest
mean annual temperature that supports closed-canopy forest today” (p.
1418). As long as there is a cool refuge within dispersal distance and as long
as dispersal is possible this increase may not be a big problem. The most
common cool refuges for plants are to migrate up in elevation. In the tropics,
however, such elevational relief is not available, making cooler refuges for
many plants and animals living in the tropics inaccessible. Around 1,200
mammals have ranges restricted to the low-latitude tropics with no easy
access to cooler refuges as the globe warms. Another group of mammals at
risk of extinction are those about 650 species that have ranges smaller than
