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 make-up (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 make-up (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?

When insects (poikilotherms) emerge in the spring?

When birds return in the spring?

How far birds fly south for the winter?

Earlier

Earlier

Earlier

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

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 record-

breaking 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.

This graph shows the relationship between spring temperature (Y-axis) and mean first flowering date (Y-axis)

Global Warming – Insect emergenceInsects are poikilotherms – How will they be affected by warmer spring temperatures?

http://jonsullivan.canterburynature.org/?p=429

Cabbage whites emerge earlier in Christchurch, New Zealand.

Global Warming – Insect EmergenceInsects 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 EmergenceInsects 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 #1Will plant budburst and insect emergence (pollinators) be on the same schedule?

.

Global Warming – Mismatch #1Will 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 #1Will plant budburst and insect emergence (pollinators) be on the same schedule?

.

Studies are limited. Some models of the outcome.

Memmot et al. 2007

ancestral

shifted

Global Warming – Mismatch #1Will 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 #1Will plant budburst and insect emergence (pollinators) be on the same schedule?

.

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.

Least amount of mismatch

Global Warming – Mismatch #1Will plant budburst and insect emergence (pollinators) be on the same schedule?

.

FIG. 4. (a) Relationships between seed-set success (seed/ovule ratio) and flowering-onset date, and (b) relationships between seed-set 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.

Least amount of mismatch

Later flowering data seems to bring more seed-set.

But mismatch (+ or - ) between flowering time and bumblebee presences reduces seed set.

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

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).

Leave date has become earlier over time.

Global Warming – Trends in Birds

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).

Spring arrival dates for the red-eyed vireo.

What is the trend?

Global Warming – Trends in Birds

For some species, as temperature has increased, so has the mean arrival date.

Global Warming – Mismatch # 2Will returning birds and emerging insects be on the same schedule?

Global Warming – Mismatch # 2Will returning birds and emerging insects be on the same schedule?

Global Warming – Mismatch # 2

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?

Parus major

Global Warming – Mismatch # 2

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?

Parus major