Effects of Climate Change on Species and
Ecosystems
Dr. David Karowe
Department of Biological Sciences
Some species are already responding to climate change
1. Geographic range shifts
2. Phenological shifts (seasonal timing)
3. Changes in population size
For plants, most documented range changes are
altitudinal shifts
e.g. the hardwood/conifer transition zone on Vermont
mountains moved upslope ~100 meters from 1962-2005
Some animals are expanding their ranges poleward
e.g. some North American birds
Golden-winged
warbler
Swainson’s
thrush
Black-billed
cuckoo
Many plant species now leaf out and flower
significantly earlier
In Ohio, budburst for white oak is now 23 days earlier
than around 1900
May 3 → April 10
For plants and animals, observed range and
phenological shifts provide a clear “climate signal”
However, most plants and animals have not yet displayed
any range shift…
e.g. 79% of North American birds
Black-capped chickadee
White-throated sparrow
… or phenological shift
e.g. 84% of British plants
Yellow sweet clover
Roundleaf geranium
Species that have not been tracking climate change are
already declining
- in Thoreau Woods over the last 150 years, major
declines for plant species with no phenological shift
Blueberry family
Rose family
Dogwood family
- European bird species that are not
migrating earlier are also declining
Pied flycatcher
What does the future hold?
It depends on the choices we make
What is the likely future fate of species?
Climate Envelope Modeling is used to predict
future changes in range and population size
General approach:
a. Determine the levels of important climate variables
(usually temperature and precipitation) that occur within
the species’ current geographic range
b. Use climate models to predict where those levels will exist
in the future
c. Make an assumption about dispersal (usually “full” or
“none”)
d. Compare current and future suitable area to infer
population increase or decrease
What is the fate of 26 species of European forest herbs?
- woodland horsetail is predicted to decline, due to
shrinking range
current
future
- wild peony is predicted to increase, due to increased range
current
future
- but fate of European cohosh is unclear, since it must
migrate to reach its future habitat
?
- even if suitable habitat exists,
species may not be able to
reach it in time
Australian Banksia are very dry-adapted species,
so will they be “climate winners”?
Typical result: many more climate losers than winners
Under 2o warming with full dispersal: 21 winners
80 losers (5 go extinct)
Under 4o warming with no dispersal:
0 winners
97 losers (24 go extinct)
Under 2o warming, huge losses are predicted for
5,200 African plant species
40% of species go extinct (full dispersal)
55% of species go extinct (no dispersal)
African mammals are likely to be adversely affected
For 275 species under 3.5o warming :
20% extinction (full dispersal)
40% extinction (no dispersal)
Which species are particularly vulnerable?
1.
2.
3.
4.
Species that have nowhere to go
Species that live in the tropics
Species that have specific timing requirements
Species that live in coral reefs
High latitude species may have nowhere to go
- most, but not all,
polar bear populations
are predicted to decline
drastically by 2050
Alaska
Seals also rely on sea ice, so are highly vulnerable too
Scandinavian bird species are predicted to lose 80%
of their suitable habitat by 2080
In Antarctica, Emperor and Adelie penguins need ice
but Chinstrap and Gentoo penguins nest on land
High altitude species may also have nowhere to go
Globally, 18% of Earth’s 1,009 montane bird species
are predicted to lose at least half of their range by 2100
Tropical species have low temperature ranges, and are
very likely to experience “disappearing climates”
Low
Moderate
Probability of disappearing climate
Therefore, tropical species are likely to be
particularly vulnerable
Where do most of Earth’s species live?
High
Migrating species are likely to be vulnerable because
of their specific timing requirements
- due to loss of synchrony at important stopover sites
- daylength and star patterns
vs. temperature
Coral reef species are likely to be particularly vulnerable
because both warming and ocean acidification can cause
bleaching
Even 2o warming is likely to cause a massive increase
in bleaching events
Acidification alone may make most or all of the ocean
unsuitable for corals
- 650 ppm CO2 may cause near total loss of coral reefs
Climate change has the potential to cause
Earth’s 6th mass extinction
What will climate change mean for Michigan species?
In Michigan, 22 tree species are predicted to decline by
50-100% by 2100, including:
sugar maple
balsam fir
American beech
big tooth and trembling aspen
northern white cedar
20 southern species are predicted to arrive in Michigan
loblolly pine
sweetgum
shortleaf pine
Virginia pine
sugarberry
50 Michigan bird species predicted to decline by 50-100%
Common loon
Evening
grosbeak
White-throated
sparrow
Red-breasted
nuthatch
Veery
Magnolia
warbler
Yellow-bellied
sapsucker
Blackburnian
warbler
15 new species are predicted to arrive in Michigan
northern
bobwhite
Mississippi
kite
yellow-billed
cuckoo
scissor-tailed
flycatcher
little blue
heron
painted
bunting
cattle egret
summer
tanager
Bottom Line:
1. We’re causing climate to change at an
alarming rate
2. If we continue on our current path, the future
is very likely to include unprecedented
hardships for all of Earth’s species, including
humans
3. Many of the worst scenarios can be avoided by
choices we have available today
Global Warming Train Ad included here; can be seen at
http://www.youtube.com/watch?v=s-_LBXWMCAM
Thank you for listening
Now please tell others