Assisted Migration for
Forest Regeneration
Examples from Canada
and a bit on USFS policy
Connie Millar
USDA Forest Service
Pacific Southwest Research Station
Albany, California USA
cmillar@fs.fed.us
Adaptation Options in the
Face of Ongoing Change
- Promote Resistance (short term)
- Increase Resilience (short term)
- Assist Ecosystems to Respond
- Realign Altered Ecosystems
Millar et al. 2007
Assisted Migration as an Adaptation Tool
(proactive/response)
Assumption: the rate of climate change is
estimated to exceed [in some places and for
some species] the potential adaptation rates
and migration speeds of forest tree species
Canadian Council of Forest Ministers, 2008:
“…ensure all disturbed or harvested forests are promptly
reforested with species and seed sources that are adapted
to predicted future climates, using assisted migration”
Ste-Marie et al. 2011
Also called “Assisted Gene Flow”
In other words…
What is moved?
-genetic populations
-species
-species assemblages
Why is it moved? -optimize health & productivity
-promote ecosystem function
(biodiversity, watershed, disturbance, carbon)
Where is it moved? -within current range
-just outside range
-far outside current range
How is it moved? -traditional regeneration
(nursery stock; seedlings)
Ste-Marie et al. 2011
Implementation (Pedlar et al. 2011 )
Step 1: Selecting Species
Vulnerability Assessments
Sensitivity, Adaptive Capacity, Exposure
genetic diversity; dispersal capacity;
phenotypic plasticity; timescale (rotation length)
Target species projected to have most declines in productivity
provenance tests; genecology modeling
Risk Assessments
Probability of success in new location
EM fungi; insects & pathogens; herbivory; maladaptation
Risk to ecosystem at new location
invasiveness; genetic contamination; introduced diseases
Framework to inform decision-making for assisted
migration in Canada (Fig 1., Winder et al. 2011)
Vulnerability Assessment Tools for AM
(refs in Beardmore and Winder 2011)
-NatureServe Climate Change Vulnerability Index, vs 2.1
-System for Assessing Vulnerability of Species to Climate Change, vs 2.0
-Forest Tree Genetic Risk Assessment Systems, vs 2.0
-Index for Predicting Tree Species Vulnerability
-Torreya Guardians
-Seeds of Success Program
Factors: Species analyzed; Integration of climate projection
models; Total number of factors in assessment; Uncertain
analyses; Species assessment output
Step 2: Determining Migration Distance
A. Use Current and Projected Climate – Provenance Data Not
Available
Climate similarity between future climate for
North Bay and current climate at all points
North Bay
-Find matches between current
climate (seed source) and
projected future climate
(planting site)
-Target climate at 1/3 the
rotation time in future
Climate similarity between
current climate for North Bay
and future climate at all points
Tools: Seedwhere
McKenney et al. 1999
Warm colors = closer match
B. Use Provenance Data
Transfer functions determined from provenance studies
Sudbury (current)
Critical Seed Transfer
Distance:
Maximum geographic,
climatic, or adaptive
genetic distance that
seed can be transferred
and retain acceptable
level of growth and
adaptation
Migrated seedprocurement area
for Sudbury
Pedlar et al. 2011
Migrated seeddeployment area
for Sudbury
Step 3: Incorporating Uncertainty
Into Seed Transfer Decisions
1. Locate the planting site or seed source in the
overlap of zones from multiple climate projections
(“ensemble approach”)
2. Plant a site using multiple seed sources, each from
slightly different climate zones (“bet hedging”,
“composite provenancing”, “portfolio approach”)
Practice Adaptive Management:
Learn and Adjust As You Go
Step 4: Procuring Seed
Use standard procedures for seed
collection (wild), seed production (seed
orchards), storage, and long-term banking
Step 5: Selecting Planting Sites
* Determine specific planting sites within new zone
from fine-scale features (land cover, soil,
topography) relevant to species’ site requirements
* Multiple sites recommended – conduct as
experiment
Step 6: Establishment Considerations
Use standard procedures and guidelines for
planting, with some extra considerations:
* Added incentive to optimize genetic diversity
(e.g., Ne) and use best cultural practices
* If Portfolio Approach used, consider value of
random vs. blocked design in plantations
Conduct projects as experiments
Step 7: Post-Establishment
Considerations
Use standard procedures but extra incentive
to attribute success or failure:
* Water, weed, control pests & predators
* Monitor survival & health conditions in early years
* Measure growth & adaptive traits
(compare to no-climate-change “control”)
* Monitor impacts to native ecosystem
(Naturalizing? Effects on native spp?)
Conduct projects as experiments!
Projects and Examples in Canada
Amendments to Seed Transfer Policy (Pedlar et al. 2011):
*2009: BC Forest Policy amended
to increase upper elevation limits
of orchard seed zones and seed
transfer distances by 200 m
*2010: BC Forest Policy amended
to permit western larch to be
moved outside its existing native
range to climatically suitable areas
Development of a Climate-Based Seed Transfer
System (Leech et al. 2011; O’Neill et al. 2008, in press)
*Initiative to convert BC’s geographic-based seed transfer system
into a climate-based system
Goals
1) Ensure that each plantation
receives seed sources best
adapted to the climate of
the site
2) Maximize the area each
seed source can be used
3) Facilitate assisted migration
Assisted Migration
Adaptation Trial (AMAT)
*48 seed sources
*48 test sites
*15 species
*Est 2008
BC Ministry of Forests, contact: Greg O’Neill
2013
No specific USFS policy yet
on Assisted Migration
Relevant USFS Policy:
• Reforestation Policy
FSM 2472.03
• Genetic Resources Management
FSM 2475.03
• Native Plant Material Policy
FSM 2070.3
The Current Bottom Line on USFS Policy
(Johnson et al. 2013)
“In general, these statements imply that the only instance
one should engage in assisted migration on an operational
basis is when past scientific research supports success.”
“Untested assisted migration can take place if it is part of a
research or administrative study.”
“In all cases, monitoring is required.”
 Report recommends establishing
common-garden tests for lesser
known species and assisted
migration trials
References:
AMAT: www.for.gov.bc.ca/hre/forgen/interior/AMAT.htm
Beardmore and Winder. 2011. Forestry Chronicle: 745-754
Erickson, et al. 2012. Washington D.C. USDA FS, Forest Management: 1-19
Johnson et al. 2013. Proceed. 60th Annual W Intntl Forest Disease Work Conf
2012, Tahoe City, CA (Brown and Palacious, Editors): 35-41
Leech et al, 2011. BC Journal Ecosystems & Mgmt 12: 18-34
Millar, et al. 2007. Ecological Applications 17: 2145-2151
O’Neill et al. 2008. BC Ministry For, Range, Res. Tech Rpt 048
Pedlar et al. 2011. Forestry Chronicle 87: 766-842.
Pedlar et al. 2012. BioScience 62: 835-842
Ste-Marie et al. 2011. Forestry Chronicle 87: 724-730
Winder et al. 2011. Forestry Chronicle 87: 731-744
Refugia for Climate Adaptation:
“Areas that are relatively buffered from modern
climate change so as to increase persistence
of valued physical, ecological, and sociocultural resources”
Climatic buffering can result from:
--Locally decoupled climatic processes
--Complex topography
Sierra Bighorn Sheep
(Ovis canadensis sierrae)
A De-Facto Assisted
Migration Strategy
P Yeager
ESA Listed, 2000
Recovery Plan, 2007
Few et al. 2015
Extensive Assessments
Risk Analysis:
-climate resilient
-source pop’n PVA
-sensitive species
-predation/disease
-recipient pop’n PVA
Few et al. 2015
Cathedral Range: A New Herd Unit
“Refugium”, Yosemite NP
Translocations
happened
last week!
J Kim
S Bumgardner
Few et al. 2015
American Pika (Ochotona princeps)
A Shcherbina
American Pika (Ochotona princeps)
-Talus matrices thermally buffered: Summer cool, winter warm
-Thermal processes partially decoupled from free air
-Matrix lapse rates -3.2 °C/km (= ½ free air value)
-Persistent springs support “stable” wetlands
Temp °C
Millar et al. 2010, 2013, 2014
matrix
10/09
10/10
surface
10/11
10/12
10/13
10/14
J. Holmquist
J Spaedtke
A Smith
Options for Pikas
1. Proactive: Delineate & Improve
Areas with Good Habitat with Healthy Populations
A Smith
Mono Basin pika range: 2190—3980 m; 1800 m elev span
Abundant, high-quality habitat;
High connectivity;
Large elevation span;
Saturated pika populations
AM Options: Expand dispersal opportunities
Trail wall
Building foundation
Mine equip
Mining ore dump
Highway rip-rap
Refugia Options for Pikas
2. Reactive: Realign declining populations
Nevada
Combine Adaptation Tools:
Assisted Migration with Refugia
Assess:
Site Selection: climate-resilient; elevation
gradients; abundant, high quality habitat (seasonal);
connectivity; predator/disease; historic habitat
Recipient Ecosystem: sensitive spp; community
dynamics; predator-prey relations
Source population: viability, genetic
diversity, demography, impacts to
source ecosystem
*
Millar and Grayson in prep
Potential Refugia/Assisted Migration Location: Snake Range, NV
Temp °C
NB: I am not advocating this action. Many more assessments
would be needed, even if reintroduction were deemed appropriate
matrix
10/1/12
surface
10/1/13
8/1/14