Transcript Lecture 9 - Response of organisms to climate change

Global Warming – not an objective issue
Global Warming - Terminology
Phenotypic Plasticity – the ability of an organism with a given
genetic make-up (genotype) that can alter its development
or expression of a characteristic in response to the
environment the organism encounters.
Phenology – The study of the timing of natural events.
Examples include when birds return to nest, the flowering
of plants, and when lakes freeze over.
Poikilothermic – the internal temperature of an organism
varies with the temperature of the environment.
Coevolution – When two species evolve in tandem, with the
reciprocal changes in one species providing some basis
for the evolution in the other species.
Global Warming - Terminology
Phenotypic Plasticity – the ability of an organism with a given genetic makeup (genotype) that can alter its development or expression of a
characteristic in response to the environment the organism encounters.
Hydrangea flower color as a function of soil pH.
Global Warming - Terminology
Phenotypic Plasticity – the ability of an organism with a given genetic makeup (genotype) that can alter its development or expression of a
characteristic in response to the environment the organism encounters.
Phenotypic plasticity in a caterpillar feeding on oak.
Caterpillar fed leaves
Caterpillar fed flowers
Global Warming - Terminology
Poikilothermic – the internal temperature of an organism varies
with the temperature of the environment.
These are often ectotherms. Often mislabeled as “cold-blooded”
Global Warming – Major Trends
The phenology of organisms will change: How?
When leaves emerge (budburst) on trees
and shrubs in the spring? Earlier
When insects (poikilotherms) emerge in the
spring? Earlier
When birds return in the spring? Earlier
How far birds fly south for the winter? Not as far
Global Warming – Plant Budburst
The phenology of organisms will change: How?
3 factors control budburst:
1) Degree of winter chilling
2) Photoperiod (daylength
relative to night length)
3) Spring temperatures
Global Warming – Plant Budburst
The phenology of organisms will change: How?
Beech (Fagus) Oak and Hackberry exhibit
little plasticity. Budburst under genetic control.
Budburst largely controlled by photoperiod.
Native species such as hornbeam,
witchhazel, poplar, & birch only become
temperature sensitive after a winter chilling
requirement has been met.
Some introduced species are
photoperiod insensitive. Spring budburst
closely tracks temperature, such as in
lilac (Syringa) and cherry trees (which
are of central Asian descent)
Global Warming – Flowering time
This graph shows the
relationship between spring
temperature (Y-axis) and
mean first flowering date (Yaxis)
Plants flower earlier on average in warm years than in cool years, as indicated in this
graph of common spring wildflowers in Concord, Massachusetts. Many of the
observations from cool weather years were gathered by Thoreau. The flowering dates for plants in recordbreaking warm years of 2010 and 2012 were within the range of predicted values from earlier years. (Source: Ellwood et al. 2013. PLoS ONE
doi:10.1371/journal.pone.0053788). Unless specified otherwise, photographs are made available under an Attribution-Share Alike 2.0 License with date and
photographer as listed. 1. serviceberry (Amelanchier canadensis), © 2011 personal collection of R. Primack, 2. marsh marigold (Caltha palustris), © 2009 walker_bc,
3. pink lady slipper (Cypripedium acaule), © 2012 Graham Hunt, 4. rhodora (Rhododendron canadense), © 2012 Andrew Block, 5. nodding trillium (Trillium cernuum),
© 2008 Ed Post, and 6. highbush blueberry (Vaccinium corymbosum), © 2007 Anita363.
Global Warming – Insect emergence
Insects are poikilotherms – How will they be affected by warmer spring temperatures?
Cabbage whites emerge
earlier in Christchurch,
New Zealand.
http://jonsullivan.canterburynature.org/?p=429
Global Warming – Insect Emergence
Insects are poikilotherms – How will they be affected by warmer spring temperatures?
Some species are
emerging earlier in the
spring.
But butterflies in urban
areas are emerging later.
Too warm? Impacts
butterfly development.
Global Warming – Insect Emergence
Insects are poikilotherms – How will they be affected by warmer spring temperatures?
Some species are
emerging earlier in the
spring.
But butterflies in urban
areas are emerging later.
Too warm? Impacts
butterfly development.
Diamond et al. 2014
Global Warming – Mismatch #1
Will plant budburst and insect emergence (pollinators) be on the same schedule?
.
Global Warming – Mismatch #1
Will plant budburst and insect emergence (pollinators) be on the same schedule?
Studies are limited. Some models of the outcome.
.
Hegland et al. 2009
Global Warming – Mismatch #1
Will plant budburst and insect emergence (pollinators) be on the same schedule?
Studies are limited. Some models of the outcome.
.
ancestral
shifted
Memmot et al. 2007
Global Warming – Mismatch #1
Will plant budburst and insect emergence (pollinators) be on the same schedule?
.
PLATE 1. Overwintered queen bee (Bombus hypocrita
sapporoensis) visiting Corydalis ambigua flowers. Photo
credit: G. Kudo.
Global Warming – Mismatch #1
Will plant budburst and insect emergence (pollinators) be on the same schedule?
.
Least amount of mismatch
FIG. 1. Relationship between phenological mismatch between plants
and pollinators (flowering-onset date and bee detection date) and
flowering-onset date in three populations of Corydalis
ambigua (Papaveraceae) in three natural deciduous forests in
Hokkaido, Japan. The extent of phenological mismatch is simply
determined by the time of flowering irrespective of populations.
Global Warming – Mismatch #1
Will plant budburst and insect emergence (pollinators) be on the same schedule?
.
Later flowering data seems to bring
more seed-set.
But mismatch (+ or - ) between
flowering time and bumblebee
presences reduces seed set.
Least amount of mismatch
FIG. 4. (a) Relationships between seed-set success (seed/ovule
ratio) and flowering-onset date, and (b) relationships between seedset success and phenological mismatch across three populations
of Corydalis ambigua. The effect of flowering time on seed-set
success is consistent among populations, whereas the effect of
phenological mismatch on seed-set success varies between
populations. Refer to Table 3 for statistical results.
Global Warming – Trends in Birds
The phenology of organisms will change: How?
Global Warming – Trends in Birds
The phenology of organisms will change: How?
If birds do not travel
as far south for the
winter…
…will they return
earlier in the spring?
Global Warming – Trends in Birds
Birds are arriving in
Oxforshire 8 days
earier in the spring.
Why? Warmer
temperatures in their
sub-Saharan African
wintering grounds.
But they are also
leaving 8 days earlier
in the fall.
Why? Warmer
summer temperatures
in Oxfordshire.
Global Warming – Trends in Birds
Leave date has become
earlier over time.
Arrival date has become
earlier over time.
Fig. 2.Linear regressions on the arrival date (filled circles, solid line) and departure date (open circles, dashed line) of Northern House Martins, Delichon
urbica, in Oxfordshire, from 1971 to 2000. Arrival date: slope = –0.671, r2 = 0.243, P < 0.08. Departure date: slope =–0.647, r2 = 0.207, P < 0.02. There
is no significant difference between the two slopes (t = 0.101, d.f. = 54, P > 0.05).
Global Warming – Trends in Birds
Spring arrival dates for the redeyed vireo.
What is the trend?
The red-eyed vireo (Vireo olivaceus) is one of the most common long distance migrants of eastern North America and therefore has the most
geographically complete coverage in the dataset. Like all species examined (see all maps in Appendix S1), the red-eyed vireo demonstrates a strong
latitudinal gradient in arrival date. In 2010, birds first arrived in Georgia in the first week of April, but did not arrive in the northeastern and north-central
U.S. until mid- to late May (Figure 2).
Global Warming – Trends in Birds
For some species, as temperature
has increased, so has the mean
arrival date.
Global Warming – Mismatch # 2
Will returning birds and emerging insects be on the same schedule?
Global Warming – Mismatch # 2
Will returning birds and emerging insects be on the same schedule?
Global Warming – Mismatch # 2
Parus major
32-year Dutch study with warming spring
temperatures:
- Timing of caterpillar advanced.
- Phenology of birds has not changed.
Peak of caterpillar abundance coincides
with egg laying date – when need for
caterpillars is low.
Are Dutch Great tits displaying plasticity?
Global Warming – Mismatch # 2
Parus major
47-year English study with warming spring
temperatures:
- Timing of caterpillar advanced.
- Phenology of birds advanced.
Peak of caterpillar abundance coincides
with chicks in nest – when need for
caterpillars is greatest.
Are English Great tits displaying plasticity?