Genecology, Restoration, and
Adapting to Climate Change
Brad St.Clair
USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR
Workshop on Restoring and Sustaining Western Landscapes:
Interaction with Climate Change
2009 Ecological Society of America Annual Meeting, Albuquerque, NM
Photo: Berta Youtie
When considering ecosystem responses to
climate change, it is important to consider
genetics of adaptation and genetic variation in
adaptive traits.
Three reasons:
1. Plants are genetically adapted to their local
climates – populations, not species, are the
important biological unit of interest
2. Evolutionary adaptation will determine what
happens to plant populations given climate change
3. Management of genetic variation may positively
influence how plants respond and adapt to climate
change
Three questions:
1. How are plants adapted to their local
climates?
2. Will plants naturally adapt to future
climates?
3. What can we do to help plants adapt
to future climates?
Adaptation
“Evolutionary” adaptation”
The process whereby an organism becomes
better suited to its environment
2. A characteristic of an organism whose form is
the product of natural selection in a given
environment
1.
“Societal” Adaptation
The adjustment of natural or human systems to
new environments, which moderates harm or
exploits opportunities (IPCC 2001)
1. How are plants adapted to their local climates?
Evidence for adaptation:
1.
2.
3.
Correlation between a character and environmental
factors - the same form occurs in similar environments
Comparisons of naturally-occurring variants in
environments where they are hypothesized to function
as adaptations
Direct evidence from altering a character to see how it
affects function in a given environment
Evidence for adaptation comes from common
garden (provenance) studies
Genecology
• The study of interspecific genetic variation
of plants in relation to environments
(Turresson 1923)
• Seeks correlations between “plant type” and
“habitat type”
• Consistent correlations are taken to indicate
adaptive significance
Evidence for adaptation: Correlations between traits and
source environments - Douglas-fir Genecology Study
Grow families in a
common environment
Measure many
adaptive traits
Collect
seed
from
many
trees
GIS
Combination of Variables, Primarily Growth
Douglas-Fir of Western OR and WA
3
2
1
0
Traits vs
source
environment
-1
-2
-3
-4
-5
-10
-8
-6
-4
-2
0
2
December Minimum Temperature
4
6
Douglas-Fir Genecology Study
Fall cold damage
Bud-set
r = 0.79
Qst = 0.68
r = 0.76
Qst = 0.29
Biomass
Bud-burst
r = 0.52
Qst = 0.13
r = 0.60
Qst = 0.21
1. Populations differ
2. Traits are correlated with source environments
3. Different traits show different patterns and scales of adaptation
•
Ultimately interested in survival, growth and reproduction
Differences among species:
distance needed to detect genetic differences in
Northern Rockies (Rehfeldt 1994)
Species
Douglas-fir
Elev.
(m)
Frost- Evolutionary
free days
mode
Specialist
200
220
370
18
20
33
38
40
54
Intermediate
Western redcedar
420
450
600
Western white pine
none
90
Generalist
Lodgepole pine
Engelmann spruce
Ponderosa pine
Western larch
Specialist
Intermediate
Intermediate
Generalist
Bluebunch Wheatgrass Genecology Study
Collections from:
127 populations
2 families per population
5 cultivars
Planted at 3 common garden test sites in 2006:
Central Ferry, WA – warm, dry
Lucky Peak Nursery, ID – cooler, dry
Pullman, WA – cold, wet
Measured for 22 traits:
Size
Phenology
Morphology
Correlations of individual traits with climate
At Lucky Peak, 2008 data
Dry Wt
Inflor
No.
Heading
Date
Bloom Mature
Date
Date
Plant
Form
Leaf
Form
Awns
Jan Temp
0.12
0.11
0.02
0.17
0.15
-0.07
0.15
0.04
Aug Temp
-0.09
-0.01
-0.19
0.07
0.13
0.07
0.28
-0.33
Spring Frost Date
-0.03
-0.07
0.25
0.09
-0.07
0.04
-0.17
0.29
Fall Frost Date
-0.03
0.04
-0.21
-0.02
0.06
0.00
0.16
-0.26
Annual Precip
0.22
0.01
0.10
-0.03
0.02
-0.23
-0.28
0.27
Aug Precip
0.22
0.05
0.08
-0.17
-0.13
-0.21
-0.23
0.27
In general, correlations with climate are not strong.
Relative to trees, no strong local adaptation.
• Larger plants are from wetter areas.
• Plants with later heading dates are from areas with later spring frost
and earlier fall frost
• Plants with upright form are from areas with less precipitation.
• Plants with narrow leaves are from hot, dry areas.
• Plants with longer awns are from areas with later spring frost, earlier
fall frosts, cooler summers, and more precipitation.
California/Mountain Brome (Bromus carinatus)
Two studies:
1. Blue Mountains - USFS R6/ARS Erickson/Johnson
– 209 sources + Bromar at 2 sites
2. Willamette Valley – USFS Doede
– 107 sources at 2 sites
Conclusions:
• Considerable population variation in growth, form,
and phenology
• Considerable differences between regions
• But weakly associated with climate (r<0.5)
Mather
El. 1,400 m
Native to
three different elevations
planted at three different
elevations
(Clausen, Keck & Hiesey 1940)
Stanford
El. 35 m
Potentilla glandulosa from
Timberline
El. 3,030 m
Evidence for adaptation: Comparisons of naturally-occurring
variants in native environments – reciprocal transplant studies
Stanford
El. 35 m
Mather
Timberline
El. 1,400 m El. 3,030 m
Grown at
Response functions derived from lodgepole pine provenance tests
in British Columbia
What about genetic variation at the level of DNA?
Patterns of Adaptive Molecular Genetic Diversity
Eckhart, Neale, et al. 2009
Neutral Genotype
Phenotype
Genotype - Non-neutral and
associated with phenotype
2. Will plants naturally adapt to future climates?
Three possibilities when environments change:
1.
•
Move
Migrate to new habitats where suited
2. Stay
•
•
Acclimate by modifying individuals to new
environment (phenotypic plasticity)
Evolve, primarily through natural selection of
better suited individuals
3. Disappear
•
Extinction of local population
What is the potential for migration?
• Evidence for range expansion northward
and up in elevation
• Estimates of past migration rates vary
– Davis and Shaw 2001: 200-400 m per yr
– Aitken et al 2007: 100- 200 m per yr
• But current rates of climate change
would require 3-5 km per yr
What is the potential for evolution
through natural selection?
Important factors include:
• Phenotypic variation
• Heritabilities
• Intensity of selection/fecundity
What is the potential for evolution
through natural selection?
Important factors include:
•
•
•
•
Phenotypic variation
Heritabilities
Intensity of selection/fecundity
Generation turnover
Lenoir et al. 2008. A significant upward shift in plant species optimum
elevation during the 20th century. Science 320: 1768-1771.
Optimum elevation = maximum probability of presence
Avg optimum elevation shift = 29 m per decade
Much quicker for grassy species compared to woody species:
grassy species: ~ 90 m shift between 1986-2005 compared to 1905-1985
woody species: ~30 m shift
What is the potential for evolution
through natural selection?
Important factors include:
•
•
•
•
•
•
•
Phenotypic variation
Heritabilities
Intensity of selection/fecundity
Generation turnover
Levels of gene flow
Mating system
Structure of genetic variation/steepness of clines
What is the potential for evolution
through natural selection?
Important factors include:
•
•
•
•
•
•
•
•
•
Phenotypic variation
Heritabilities
Intensity of selection/fecundity
Generation turnover
Levels of gene flow
Mating system
Structure of genetic variation
Central vs peripheral populations
Trailing edge vs leading edge
What is the potential for evolution
through natural selection?
Important factors include:
•
•
•
•
•
•
•
•
•
•
Phenotypic variation
Heritabilities
Intensity of selection/fecundity
Generation turnover
Levels of gene flow
Mating system
Structure of genetic variation
Central vs peripheral populations
Trailing edge vs leading edge
Population size
What is the potential for evolution
through natural selection?
Important factors include:
•
•
•
•
•
•
•
•
•
•
•
Phenotypic variation
Heritabilities
Intensity of selection/fecundity
Generation turnover
Levels of gene flow
Mating system
Structure of genetic variation
Central vs peripheral populations
Trailing edge vs leading edge
Population size
Biotic interactions
What is the potential for evolution
through natural selection?
Important factors include:
•
•
•
•
•
•
•
•
•
•
•
•
Phenotypic variation
Heritabilities
Intensity of selection/fecundity
Generation turnover
Levels of gene flow
Mating system
Structure of genetic variation
Central vs peripheral populations
Trailing edge vs leading edge
Population size
Biotic interactions
Genetic correlations
Species and populations most
threatened by climate change:
•
•
•
•
•
Long-lived species
Inbreeding species
Small populations
Fragmented, disjunct populations
Populations at the trailing edge of climate
change (southern, low elevation)
• Species or populations with low genetic
variation
• Rare species
• Populations threatened from habitat loss, fire,
disease, insects
What about phenotypic plasticity?
• Phenotypic plasticity = the ability of an individual to change its
characteristics (phenotype) in response to changes in the
environment
• Phenotypic plasticity is common in plants
– Plants modify their phenology and growth in response to changes in
environments
•
•
•
•
Bud-set
Bud-burst
Flowering
Acclimation to drought
• However, patterns of genetic variation in adaptive
characteristics associated with environmental variation suggest
that phenotypic plasticity is insufficient
– No single phenotypically plastic genotype is optimal in all
environments
3. What can we do to help plants
adapt to future climates?
3. What can we do to help plants
adapt to future climates?
1.
Deploy populations adapted to future climates
Seed zones and breeding zones are
used to ensure adaptability
USDA Plant Hardiness Zones
Randall and Berrang
(2002) WA Dept Nat
Resources
Seed zones and
breeding zones are
largely delineated
based on climate
Randall (1996) OR Dept of Forestry
Recently, efforts to develop seed
zones for native restoration species
Recommended four seed zones for
the Blue Mountains, oriented eastwest
But, seed zones and seed transfer rules
developed for today‟s climates may not be
appropriate for future climates.
Assisted migration = Movement of species,
provenances, or breeding populations to „new‟
sites where they are expected to be better
adapted in the future
Present
2030
2060
2090
Douglas-fir
Seed zone #4
0-1000 ft
Seed zone
Figures by Lauren Magalska, OSU
Present
2030
2060
2090
Douglas-fir
Seed zone #4
0-1000 ft
Seed zone
Climate
Figures by Lauren Magalska, OSU
Present
2030
2060
Douglas-fir
Seed zone #4
0-1000 ft
Seed zone
Climate
2090
Present
2030
2060
Douglas-fir
Seed zone #4
0-1000 ft
Seed zone
Climate
2090
Present
2030
2060
Douglas-fir
Seed zone #4
0-1000 ft
Seed zone
Climate
2090
Assisted Migration for Douglas-Fir
Corresponds to a temperature change of 2.5 to 6.2ºC
Climate change and assisted
migration of lodgepole pine
Lodgepole pine provenance test in B.C.
Change in productivity (m 3/ha)
70
50
30
10
-10
— Optimized sources
— Local sources
-30
-50
-70
0
140 populations
60 test sites
2012
|
1
2038
|
2
2063
|
3
2088
|
4
2114
|
5
2139
6
MAT increase (°C)
Wang et al. (2006) Global Change Biol. 12:2404.
 Local = productivity increased by 7% up to 1.5ºC (2030), but decreased above 2ºC.
 Optimal = productivity increased by 14-36%.
Web-based Seed Transfer
Decision-Support Tool
• Will help select appropriate
seedlots for planting or
target proper markets with
specific seedlots
• Will work for multiple
species using multiple
climatic variables and various
climate change scenarios
Developed by Ron Beloin, Glenn Howe, Brad St.Clair
Center for Forest Provenance Data
Objectives:
1.
Archive data from long-term
provenance tests and
seedling genecology tests
2.
Make datasets available to
researchers through the web
May eventually include species other than trees
3. What can we do to help plants
adapt to future climates?
1.
Deploy populations adapted to future climates
(assisted migration)
2. Promote natural migration and gene flow
Avoid fragmentation and maintain corridors for gene flow
But,
• Seed migration may not be
sufficient
• Pollen flow may be limited
by temperature-associated
flowering phenology
3. What can we do to help plants
adapt to future climates?
1.
Deploy populations adapted to future climates
(assisted migration)
2. Promote natural migration and gene flow
3. Enhance genetic diversity
•
•
•
Deploy provenance mixtures within sites or across
landscapes
Maintain diversity within provenances
Establish genetic outposts for facilitating gene
flow into adjacent native stands – small number
may be effective
3. What can we do to help plants
adapt to future climates?
1.
Deploy populations adapted to future climates
(assisted migration)
2. Promote natural migration and gene flow
3. Enhance genetic diversity
4. Conserve genetic diversity
Conserving Genetic Diversity
In situ conservation
• Locate reserves in areas of high environmental and
genetic diversity
• Reduce disturbance probability and intensity
– thinning, prescribed fire, fuels reduction, insect traps
• Supplement existing variation with genetic outposts
Ex situ conservation
• Seed collections becomes more
important with increasing threats
to in situ reserves
• Assisted migration (plantings) may
also be considered a form of ex
situ conservation
Priorities for Conservation
•
•
•
•
•
•
•
Long-lived species
Picea mexicana
Rare species
Rare, valuable variants
Low genetic variation
Small population sizes
Fragmented, disjunct populations
Populations at the trailing edge of
climate change (southern, low elevation)
• Threatened from habitat loss, fire,
disease, insects
3. What can we do to help plants
adapt to future climates?
1.
2.
3.
4.
5.
Deploy populations adapted to future climates
(assisted migration)
Promote natural migration and gene flow
Enhance genetic diversity
Conserve genetic diversity
Practice selection and breeding for adaptive
characteristics
Selection and Breeding
Breed for drought hardiness and growth phenology
Tests have been developed to assess cold and drought hardiness.
Breeding per se is generally not needed – assisted migration already
available.
Breed for resistance or tolerance to pests
A long-term, expensive, difficult prospect.
Key pests are being addressed – Which others will become problematic?
Biotech approaches may be the most effective (e.g., Bt insect toxins).
Breed for broad adaptation
Testing for
drought
hardiness
Xylem
cavitation
3-cm
stem
section
Imposed drought
Cavitated cell
Summary
1. How are plants adapted to their local
climates?
2. Will plants naturally adapt to future
climates?
3. What can we do to help plants adapt
to future climates?
Acknowledgements
•
•
•
•
•
Glenn Howe – Oregon State University
Daniel Chmura – Oregon State University
RC Johnson – ARS, Pullman, WA
Vicky Erickson – USFS, Region 6
Nancy Shaw – USFS Rocky Mtn Research Station
Final model fit data well from 3 trials
Critical CU minimal CU needed
(below that level,
forcing will not
result in budburst)
Optimal CU - level
at which additional
chilling will not
reduce the minimal
time need for
forcing
Date of Spring Budburst Observed (squares) or
Predicted from Historical Records (points)
Historical data
Blue=Oly Pink=Corv
Experimental data
indicates that some
winter warming will
hasten date of spring
budburst but more
warming will delay it
as chilling is not
satisfied.
• Population variation in phenology, crown
size, fecundity associated with aridity
and temperature (r=0.55-0.71)
Lodgepole pine transfer functions for six sites in British Columbia