Biology Reference
In-Depth Information
and phenological shifts by plant and animal species showed that more
than 80% of the species involved have extended their temporal or spatial
activities in the direction expected by known physiological limitations
(Root et al. 2003). In the temperate zone and subarctic, various species of
plants and animals have extended their ranges to higher elevations and
higher latitudes. Butterflies, in particular, have proven to be sensitive indi-
cators of shifts in climatic zones. In a study of range limits of 35 species
of nonmigratory butterflies in Europe and North America, Parmesan et
al. (1999) found that 22 species extended their ranges northward by
35-240 km during the twentieth century. Only one species had expanded
southward to a significant degree. In western North America, where tem-
perature isotherms have shifted north about 105 km, the mean latitude of
populations of Edith's checkerspot (
Euphydryas editha
) has shifted north-
ward 92 km (Parmesan 1996). The sachem skipper (
Atalopedes campestris
)
has spread northward in the Pacific states by about 700 km over the past
35 yr (Crozier 2002).This butterfly, a member of a tropical genus, is intol-
erant of severe winter cold, so warming of winter temperature has prob-
ably contributed to its expansion into Oregon and Washington State. In
southeastern Arizona, several formerly common animal species disap-
peared and one new rodent species appeared (Brown et al. 1997).
In some mountainous areas, plant species have moved upward in ele-
vation as the climate has warmed. In the Scandes Mountains of Sweden,
for example, the limits of several species of evergreen and deciduous trees
and shrubs have risen by 120-375 m (Kullman 2002). In Austria, Grab-
herr et al. (1994) collected data on increased elevational limits of nine
plant species. In this region, the increase in temperature has been about
0.7°C over the past 70-100 yr. This change should correspond to an
increase of 8-10 m per decade in climate zones. Plant distribution limits,
however, increased much less, with the maximum approaching 4 m per
decade. Clearly, even over short distances, plant migration is lagging
behind the rate of climate change.
Wa r m-water marine invertebrates and fish have expanded their ranges
northward in Europe and North America. In the North Atlantic, for
example, marine copepod assemblages typical of warmer waters have
spread northward more than 10° of latitude (Beaugrand et al. 2002).
Climatic change thus is shifting the location of climatic zones to
which many species are adapted, as well as creating new climatic patterns.
At a given location, conditions change so that some species native to that
region are likely to disappear and others, native to adjacent regions, are
likely to invade. Under this scenario, the distinction between natives and
