genecology, restoration, and adapting to climate change · different traits show different patterns...

Brad St.ClairUSDA Forest Service, Pacific Northwest Research Station, Corvallis, OR

Genecology, Restoration, and Adapting to Climate Change

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

1. 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

“Evolutionary” adaptation”

“Societal” Adaptation

The adjustment of natural or human systems to new environments, which moderates harm or exploits opportunities (IPCC 2001)


1. Correlation between a character and environmental factors - the same form occurs in similar environments

2. Comparisons of naturally-occurring variants in environments where they are hypothesized to function as adaptations

3. 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

Evidence for adaptation:

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

Collect seed from many trees

Grow families in a common environment

Measure many adaptive traits

Traits vs source

environment

Douglas-Fir of Western OR and WA

December Minimum Temperature

-10 -8 -6 -4 -2 0 2 4 6

Co

mb

ina

tio

n o

f V

ari

ab

les,

Pri

ma

rily

Gro

wth

-5

-4

-3

-2

-1

0

1

2

3

GIS

Evidence for adaptation: Correlations between traits and source environments - Douglas-fir Genecology Study

1. Populations differ2. Traits are correlated with source environments3. Different traits show different patterns and scales of adaptation

• Ultimately interested in survival, growth and reproduction

Bud-set

r = 0.76Qst = 0.29

Biomass

r = 0.52Qst = 0.13

Bud-burst

r = 0.60 Qst = 0.21

Fall cold damage

r = 0.79Qst = 0.68

Douglas-Fir Genecology Study

Differences among species: distance needed to detect genetic differences in

Northern Rockies (Rehfeldt 1994)

Species

Elev.

(m)

Frost-

free days

Evolutionary

mode

Douglas-fir 200 18 Specialist

Lodgepole pine 220 20 Specialist

Engelmann spruce 370 33 Intermediate

Ponderosa pine 420 38 Intermediate

Western larch 450 40 Intermediate

Western redcedar 600 54 Generalist

Western white pine none 90 Generalist

Collections from: 127 populations2 families per population5 cultivars

Planted at 3 common garden test sites in 2006:Central Ferry, WA – warm, dryLucky Peak Nursery, ID – cooler, dryPullman, WA – cold, wet

Measured for 22 traits:SizePhenologyMorphology

Bluebunch Wheatgrass Genecology Study

Correlations of individual traits with climate

Dry Wt Inflor

No.

Heading

Date

Bloom

Date

Mature

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

At Lucky Peak, 2008 data

• 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.

In general, correlations with climate are not strong. Relative to trees, no strong local adaptation.

Two studies:1. Blue Mountains - USFS R6/ARS Erickson/Johnson

– 209 sources + Bromar at 2 sites2. Willamette Valley – USFS Doede

– 107 sources at 2 sitesConclusions:• Considerable population variation in growth, form,

and phenology• Considerable differences between regions• But weakly associated with climate (r<0.5)

California/Mountain Brome (Bromus carinatus)

Nat

ive

to

Grown at

TimberlineEl. 3,030 m

StanfordEl. 35 m

MatherEl. 1,400 m

Sta

nfor

dEl. 3

5 m

Math

er

El. 1

,400 m

Tim

berline

El. 3

,030 m

Potentilla glandulosa from three different elevations planted at three different elevations(Clausen, Keck & Hiesey 1940)

Evidence for adaptation: Comparisons of naturally-occurring variants in native environments – reciprocal transplant studies

Response functions derived from lodgepole pine provenance tests in British Columbia

Patterns of Adaptive Molecular Genetic Diversity

Neutral Genotype Phenotype Genotype - Non-neutral and associated with phenotype

What about genetic variation at the level of DNA?

Eckhart, Neale, et al. 2009

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

Three possibilities when environments change:


• 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 migration?

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 1905-1985woody species: ~30 m shift

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



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



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



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



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


1. Deploy populations adapted to future climates

Seed zones and breeding zones are used to ensure adaptability

Seed zones and

breeding zones are

largely delineated

based on climateRandall (1996) OR Dept of Forestry

Randall and Berrang

(2002) WA Dept Nat

Resources

USDA Plant Hardiness Zones

Recently, efforts to develop seed zones for native restoration species

Recommended four seed zones for

the Blue Mountains, oriented east-

west

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

2030 2060 2090

Douglas-fir

Seed zone #4

0-1000 ft

Seed zone

Present

Figures by Lauren Magalska, OSU

2030 2060 2090

Douglas-fir

Seed zone #4

0-1000 ft

Seed zone Climate

Present

Figures by Lauren Magalska, OSU

Present 2060 2090

Douglas-fir

Seed zone #4

0-1000 ft

Seed zone Climate

2030

Present 2030 2090

Douglas-fir

Seed zone #4

0-1000 ft

Seed zone Climate

2060

Present 2030 2060

Douglas-fir

Seed zone #4

0-1000 ft

Seed zone Climate

2090

Corresponds to a temperature change of 2.5 to 6.2ºC

Assisted Migration for Douglas-Fir

Local = productivity increased by 7% up to 1.5ºC (2030), but decreased above 2ºC.

Optimal = productivity increased by 14-36%.

Climate change and assisted

migration of lodgepole pine

-70

-50

-30

-10

10

30

50

70

0

2012

|

1

2038

|

2

2063

|

3

2088

|

4

2114

|

5

2139

6

MAT increase (°C)

Change in p

roductivity (

m3/h

a)

— Optimized sources

— Local sources

-70

-50

-30

-10

10

30

50

70

0

2012

|

1

2038

|

2

2063

|

3

2088

|

4

2114

|

5

2139

6

MAT increase (°C)

Change in p

roductivity (

m3/h

a)

— Optimized sources

— Local sources

Lodgepole pine provenance test in B.C.

Wang et al. (2006) Global Change Biol. 12:2404.

140 populations 60 test sites

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


1. Deploy populations adapted to future climates (assisted migration)

2. Promote natural migration and gene flowAvoid fragmentation and maintain corridors for gene flow

But, • Seed migration may not be

sufficient• Pollen flow may be limited

by temperature-associatedflowering phenology



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. 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• 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

Picea mexicana




3. Enhance genetic diversity

4. Conserve genetic diversity

5. Practice selection and breeding for adaptive characteristics

Breed for drought hardiness and growth phenologyTests 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 pestsA 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

Selection and Breeding

Imposed drought

3-cm

stem

section

Cavitated cell

Xylem

cavitation

Testing for drought hardiness




Summary

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

Experimental data

indicates that some

winter warming will

hasten date of spring

budburst but more

warming will delay it

as chilling is not

satisfied.

Historical data

Blue=Oly Pink=Corv

Date of Spring Budburst Observed (squares) or

Predicted from Historical Records (points)

• 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

genecology, restoration, and adapting to climate change · different traits show different patterns...

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