Environmental Engineering Reference
In-Depth Information
American pika (
Ochotona princeps
) (Moritz et al., 2008). In 1917 Grinnell
found it up to 2,400 m (Grinnel, 1917), but in 2004 it was recorded up to
2,900 m. The same type of analysis with similar results has also been done
on birds (Tingley et al., 2009). Changes in the species are consistent with
an increase in minimum January temperature by about 3°C.
In prehistoric times many species communities were composed of
species that today are not found together (Overpeck et al., 1992). These
so-called no analog communities foreshadowed what we are now observ-
ing; many species are moving differentially, which means the various biotic
interactions existing within some species communities are changing. For
example, the predator-prey cycle will be broken if one species moves into
areas where the other does not occur. A situation that could cause concern is
if the prey is a pest on our crops or a disease vector, and they no longer are
held in check by the predator. Even if mutalistic interactions are disrupted,
such as an insect that commonly pollinates a crop shifts, another insect
pollinator most likely will move in, but perhaps not immediately. In several
locations around China people are having to hand pollinate apple and pear
trees to counter the loss of productivity due to a significant decline in the
abundance of natural pollinators (Partap et al., 2001).
Changes in Size and Shape, Genetics, and Behavior,
As Earth has warmed many species are showing different types of con-
current changes. Hadly (1997) documented body size changes of a small
mammal during historical (natural) climate shifts. Temporal fluctuations of
body size in woodrats are so precise that Smith and Betancourt (1998) la-
beled them “paleo-thermometers.” Indeed, two rodent species in southern
New Mexico captured from 1991 to 1998 had multiple structures, such
as hind leg, ear, and body length, showing strong correlation with a time-
appropriate climate variable (Wolf et al., 2009).
Few studies have found a change in genetics with climate change.
This could be that relatively few scientists have looked for such a change.
Bradshaw and Holzapfel (2008), however, have examined the pitcher-plant
mosquito (
Wyeomyia smithii
), and they did find genetic change (Bradshaw
et al., 2006).
Species most affected by reductions in Arctic sea-ice extent are those
with limited distributions and specialized feeding habits that depend on ice
for foraging, reproduction, and predator avoidance, including the ivory gull
(
Pagophila eburnean
), Pacific walrus (
Odobenus rosmarus divergens
), ringed
seal, hooded seal (
Cystophora cristata
), narwhal (
Monodon monoceros
), and
polar bear (
Ursus maritimus
); see Post et al. (2009) and Gilg et al. (2009).
