Environmental Engineering Reference
In-Depth Information
temperature of only ~0.6°C, many species around the globe were found to
be making many significant changes (Root and Schneider, 2002; Parmesan
and Yohe, 2003; Root et al., 2003). Species primarily exhibit two different
types of changes: the timing of various temperature-related events, such as
blooming or egg laying; and shifting their ranges to formerly cooler regions,
such as poleward and up in elevation for terrestrial species and descend-
ing deeper in the oceans for marine species (Root and Schneider, 2002;
Parmesan and Yohe, 2003; Root et al., 2003; Root et al., 2005; Parmesan,
2006; Fox et al., 2009). Species are exhibiting other types of changes, but
they are not reported as often as these two changes. Included in this “other”
category are, for example, behavioral changes, changes in size and shape,
and genetic changes.
Change in Seasonal Timing
The timing of different seasonal activities (phenology) of many species is
shifting in concert with the changing climate. Common changes in the tim-
ing of spring activities include the timing of migration in various species such
as birds, mammals, fish, and insect species (e.g., MacMynowski and Root,
2007; Ogden et al., 2008) and in budding, blooming, and leafing in plants
(e.g., Menzel et al., 2006; Crimmins et al., 2009; Primack and Miller-Rush-
ing, 2009). For example, in the case of plants, several trees in an urban to
rural setting in Ohio exhibited an earlier trend in the leafing out in the spring
(Shustack et al., 2009). The same is true for the timing of cherry blossoms
in Japan, for which data exist from the ninth century (Primack et al., 2009).
Satellite data unequivocally confirm the earlier greening of the biosphere
(Myneni et al., 1998; White et al., 2009). Of course individual examples
are not sufficient to draw generalized conclusions, thus meta-analyses have
been performed to look for consistent patterns around the globe over a large
number of species that have been observed to have been changing. For all
Northern Hemisphere species reported in the literature with more than a
10 year record showing phenological changes in the spring, the average
number of days changed in the spring observed over the last 30 years of the
20th century was ~15.5 days or ~5 days per decade earlier timing for those
species showing a phenological change in the spring (Root et al., 2003).
When both the species changing and those not changing in the same areas
are included in the study calculation, then the number of days drops strongly
to ~2 days per decade (Parmesan and Yohe, 2003). The increase in global
average temperatures over that time period was ~0.4°C, although changes
in land temperatures, especially at higher latitudes, were some factor of two
larger (IPCC, 2007a).
