Transcript Dec 2, 2011 Bigeographical Aspects of Global Wa..

The Biogeography of Global Warming
Shows the predicted warming over the 21st century due to business as usual greenhouse gas emissions as
reported by the HadCM3 climate model.
Robert A. Rohde
Plant and Animal Responses
1. Migrate
2. Adapt
3. Go extinct
Two Likely Candidates for Extinction
The American Pika (Ochotona princeps)
Evidence of Past Warming Episodes:
Arctic and Alpine Treelines
Bristlecone Pine (Pinus longaeva)
LaMarche (1973)
Variations in needle length of bristlecone pine at the upper tree line
related to temperatures in the summer, in which needle elongation takes place.
Large fluctuations in the total photosynthetic area of a tree could be produced
by sequences of unusually cool or unusually warm summers. Temperature data
are July-August mean maximum temperatures,1958 to 1971.
LaMarche (1974, Figure 3)
LaMarche (1974)
LaMarche (1974)
High Resolution Records of Recent Migration
The Speckled Wood Butterfly (Pararge aegeria)
Mean global temperatures have risen this century, and further warming is predicted to
continue for the next 50–100 years. Some migratory species can respond rapidly to
yearly climate variation by altering the timing or destination of migration, but most
wildlife is sedentary and so is incapable of such a rapid response. For these species,
responses to the warming trend should be slower, reflected in poleward shifts of the
range. Such changes in distribution would occur at the level of the population,
stemming not from changes in the pattern of individuals' movements, but from
changes in the ratios of extinctions to colonizations at the northern and southern
boundaries of the range. A northward range shift therefore occurs when there is net
extinction at the southern boundary or net colonization at the northern boundary.
However, previous evidence has been limited to a single specie or to only a portion of
the species' range. Here we provide the first large-scale evidence of poleward shifts in
entire species' ranges. In a sample of 35 non-migratory European butterflies, 63%
have ranges that have shifted to the north by 35–240 km during this century, and only
3% have shifted to the south.
Camille Parmesan et al.
Poleward shifts in geographical ranges of butterfly species
associated with regional warming
Nature 399, 579-583(10 June 1999)
A coloured grid cell indicates
more than one population in
1915–1939 (black), 1940–
1969 (red) or 1970–1997
(blue).
FIGURE 1. Twentieth-century changes in the range of Pararge aegeria in Great
Britain, plotted by presence in Ordnance Survey 10 × 10 km grid squares.
J. Lenoir, et al.
A Significant Upward Shift in Plant Species Optimum Elevation
During the 20th Century
Science 320, 1768 (2008);
Abstract
Spatial fingerprints of climate change on biotic communities are usually
associated with changes in the distribution of species at their latitudinal
or altitudinal extremes. By comparing the altitudinal distribution of 171
forest plant species between 1905 and 1985 and 1986 and 2005 along
the entire elevation range (0 to 2600 meters above sea level) in west
Europe, we show that climate warming has resulted in a significant
upward shift in species optimum elevation averaging 29 meters per
decade. The shift is larger for species restricted to mountain habitats and
for grassy species, which are characterized by faster population turnover.
Fig. 3B illustrates a larger shift for the
small grassy (associated with a fast breeding rate)
Galium rotundifolium than for the large woody
(associated with a slow breeding rate) Sorbus
aria
Modelling Potential Future Changes in Distribution