Assisted Migration: Noah’s Ark or
Pandora’s Box?
Hugh Safford
Regional Ecologist
Pacific SW Region
hughsafford@fs.fed.us
Problem statements
• The managed relocation (MR) of species is a
controversial management response to climate
change.
• Current consideration of MR emphasizes biological
concerns over difficult ethical, legal, and policy issues.
• Biological considerations have focused on the species
of concern and not the recipient ecosystems
• Ongoing managed relocation actions lack
transparency, and scientific and societal engagement.
• There are many, many cases of managed
relocation/assisted migration gone awry:
o animals in Hawaii, invasive annual plants in CA, tamarisk,
scotch broom, monterey pine…
Managed Relocation Working Group
• More than 30 scientists, scholars, and
policymakers met between 2008 and 2012 to
discuss implications and challenges of managed
relocation (assisted migration).
• Group included ecologists, economists, social
scientists, ethicists, legal experts, policy makers
and others, from management and regulatory
agencies, universities and research institutions,
and non-governmental organizations.
Purpose
• There is strong societal and scientific disagreement
about the wisdom of engaging in managed relocation
(MR) as an adaptation strategy; we sought to identify
and treat a series of fundamental questions related to
its potential use.
• Group included people initially strongly supportive of
managed relocation, and others who were strongly
opposed.
• Themes treated by the working group included (1)
basic goals of MR; (2) identification of trigger
conditions for the implementation of MR; (3) genetic
considerations; (4) legal, policy, and ethical questions;
(6) reconciling MR with existing conservation
strategies; and (7) how to deal with community- and
ecosystem-level interactions.
Key outcomes 1
• Managed relocation may prove to be necessary in
some cases, but a structured decision making
process is essential. It must integrate ethical,
legal, and scientific considerations in a way that is
both deliberative and publicly transparent.
• Resource managers need standards, protocols,
and guidelines for evaluating whether, when,
how, and for whose benefit managed relocation
might be implemented.
• Unanalyzed and unvetted MR should not be done
Key outcomes 2
• Working group publications:
– Safford et al. 2009. Eos 90
• Short summary of working group progress
– Richardson et al. 2009. Proc. Nat. Acad. Sci. 106
• Development of tool incorporating ecological and social
criteria in multidimensional framework for MR decision
making
– Schwartz et al. 2012. BioScience 62
• Calls for development of policy framework for MR, in light
of ongoing MR actions and lack of transparent
consideration of costs and benefits (biological, ecological,
legal, ethical, and political)
Key outcomes 2
• Other associated publications:
– Camacho et al. 2010. Issues in Sci. and Tech. 26
• Reassessing conservation goals in a changing climate.
– Camacho. 2010. Yale Journal on Regulation 27
• Assisted migration: Redefining nature and natural
resource law under climate change.
– Minteer and Collins. 2010. Ecol. Applications 20
• Move it or lose it? The ecological ethics of relocating
species under climate change.
Key outcomes 3
• Working group developed four broad criteria for
comparing strategies for conservation of a target
species:
– FOCAL IMPACT: the risk of negative impact of climate
change (or other anthropogenic disturbance) on the
species of interest;
– COLLATERAL IMPACT: the risk of collateral effects of
the strategy in consideration (e.g., on the recipient
ecosystem of the MR action),
– the FEASIBILITY of the strategy in question (“could we
do this?”), and
– the ACCEPTABILITY of the strategy (“should we do
this?”).
Considering MR? Basic questions to
answer
From Richardson et al. 2009. Schwartz et al. 2010 provides more info
on sources of info and ranking processes
Graphic method for comparing MR
proposals
Combines ranked scores from four criteria
Focal Impact
5
4
3
2
1
Acceptability
0
Collateral Impact
Feasibility
Graphed as the complement of CI (1-CI)
Example: the Pines
Why Pinus?
• “Pinus is without a doubt the most ecologically and
economically significant tree genus in the world.” (Richardson
and Rundel 1998)
• Pinus is the best-studied tree genus in the world, with respect
to current ecology and paleo-ecology, also with respect to
genetics and economic uses.
• Pines are among the most genetically diverse organisms (Ledig
1998)
• Very important economics and cultural links to human society.
Which pine spp. to use?
Choices based on
(1) systematics/classification (representation of each of the subgenera,
sections and subsections present in North America)
(2) ecology (representation of each of McCune’s 1988 groups of ecological
syndromes in pines)
(3) geographic and climatic distribution (east, west, north, south;
mountains, lowlands; Mediterranean, semiarid (dry continental), arid
with monsoonal moisture, wet and warm, wet continental (cold winters)…
(4) feasibility of analysis (availability of sufficient data to carry out a
meaningful analysis – thanks to Steve Jackson and Dave Richardson)
(5) Economic or cultural importance
(6) Conservation status
(7) personal communications with Steve Jackson and Dave Richardson
aided in developing the rationale
Subgenus Pinus
– Section Pinus
• Subsection Pinus
Pinus resinosa (red pine)
• Subsection Australes
Pinus elliotii and Pinus palustris (slash pine, longleaf pine)
• Subsection Contortae
Pinus banksiana (jack pine)
• Subsection Ponderosae
Pinus ponderosa (ponderosa pine)
• “Sabinianae Group”
Pinus torreyana (Torrey pine)
• Subsection Attenuatae
Pinus radiata (Monterey pine)
Subgenus Strobus
– Section Parrya
• Subsection Balfourianae
Pinus longaeva (Great Basin bristlecone pine)
• Subsection Cembroides
Pinus edulis (piñon pine)
– Section Strobus
• Subsection Strobi
Pinus strobus (eastern white pine)
• Subsection Cembrae
Pinus albicaulis (whitebark pine)
Background data: Biology
Common Name
Whitebark pine
Jack pine
Pinyon pine
Slash pine
Bristlecone pine
Longleaf pine
Ponderosa pine
Monterey pine
Red pine
Eastern white pine
Torrey pine
Source
Fire
N
Begin
Yrs
toleranc
oConser
seed
betwee e (bark Shade
t vation
McCune bearing n cone thicknes toleranc
estatus Rarity Group (yr)
crops
s rating) e
3
3 20
3-5
0
very low
1
43
3-4
0
very low
1
3 25
2-5
1
low
3
58
3
2
low-int
had
VU to use data4from aristata
3 20sensu lato
4-7in some
1 cases very low
2
1 20
5-7
1
very low
1
1 10 or 15? 2-5
2
low
EN/LR
8
45
1
2
int
2
outlier 20
3-7
2
low
2
25
3-10
1
int
EN
8
1 12
1
2
low
1, 9
1,9, 10
9
14
Degree
of
serotiny
1
2.5
1
1
1
1
1
3
1
1
2
9
Common Name
Whitebark pine
Jack pine
Pinyon pine
Slash pine
Bristlecone pine
Longleaf pine
Ponderosa pine
Monterey pine
Red pine
Eastern white pine
Torrey pine
Source
Floweri
ng
Jul
May-Jun
Jun
Jan-Feb
Jul-Aug
Feb-Mar
May-Jun
Jan-Feb
Apr-Jun
May-Jun
Feb-Mar
Cone
ripenin
g
Aug-Sep
Sep
Sep
Sep-Oct
Aug-Sep
Sep-Oct
Aug-Sep
Nov
Aug-Oct
Aug-Sep
Jun-Jul
1
1
Seeds
x1000
per kg
(mean)
5.7
289
4.2
30
40
10.8
29
29
115
58
1.1
Mean
seed
mass
(g)
0.175
0.003
0.238
0.033
0.025
0.093
0.034
0.034
0.009
0.017
0.910
Mean
seed
mass
(mg)
174.000
3.000
300.000
34.000
25.000
93.000
38.000
34.000
9.000
17.000
910.000
1
1
1
* = CLOSED CONE SPP
1
9
Seed
dispers
al
not shed
Sep*
Sep-Oct
Oct
Sep-Oct
Oct-Nov
Sep-Jan
Jan-Mar*
Oct-Nov
Aug-Sep
Sep-Dec
Seeds
x1000
per kg
(range)
4.8-6.6
156-551
3.3-5.5
21-43
39-42
6.6-15.4
22-34
23-35
66-166
39-117
0.9-1.8
Seedwing
loading
index
(mg/mm)
165
2
162
11
14
18
11
11
5
5
190
Germinat
Dispersal ion rate
agent
(lab)
B, R
30
W
77
B, R
96
W
86
W, B
88
W
95
W, B
70
W, B, R
74
W
79
W
96
R
81
9 11, 12, 13
1
mean of tests
Common Name
Whitebark pine
Jack pine
Pinyon pine
Slash pine
Bristlecone pine
Longleaf pine
Ponderosa pine
Monterey pine
Red pine
Eastern white pine
Torrey pine
Mean
longevity
(yr)
450
80
275
200
723
300?
425
85
350
325
200
Source
4, 5, 6, 7
Net
Rel
assimilat Leaf
Lead
Specific
growth
ion rate area
mass
leaf area
Invasive Rate
(mg/sq
ratio (sq ratio (g- (sq cm/g- RGR
ness (Z) (mg/g/d) cm/d)
cm/g)
leaf/g)
leaf)
max
-10.31 (from12.8
P. cembra)
(cembra)
.36 (cembra)
35.2 (cembra)
.581 (cembra)
60.6 (cembra)
22 (cembra)
8.85
38.6
0.57
77.7
0.588
132.3 no data
-8.94
4.33
31.6
0.51
66.4
0.588
114 no data
<-12.4
very slow
very slow
-6.36
32.3
0.67
58.5
0.787
74.5
34.2
0.29
30
0.58
59.1
0.612
96.6
41.7
9.27
45.8
0.61
79.8
0.676
118.1
71.1
-1.78
27.7
0.46
74
0.723
102.3
56
3.46
28.7
0.43
80.3
0.679
118.4
38.7
-7.62
18.6
0.48
40.2
0.545
73.7 no data
8
10
10
10
10
10
10
Rejmanek &
Richardson 1996
Ecology
Grotkopp et al. 2002 AmNat
Genetics
Common Name
Whitebark pine
Jack pine
Pinyon pine
Slash pine
Bristlecone pine
Longleaf pine
Ponderosa pine
Monterey pine
Red pine
Eastern white pine
Torrey pine
Notes
low pollen dispersal
distance and low
neighborhood size
high gene flow,
large neighborhood
size
1-Fst
evidence of "recent"
genetic bottleneck,
surprisingly low
inbreeding
depression
following selfing
fixed at all of 59
studied loci
sd
He
sd
1-Gst
0.204
0.143 0.0315
95.63
2.81
0.179
97.95
1.202
0.048
0.327
96.2
0.1275 0.0318 96.6 (95.9 according
1.702 to S&H but the numbe
0.1901 0.0714
95.2
4.97
0.122 0.022
89.1 6.605
0.0023 0.0033
0.1865 0.1389
0
95.1
0
4.313
Physical habitat
Native
Range
Common Name (sq km)
Whitebark pine
Jack pine
Pinyon pine
Slash pine
Bristlecone pine
Longleaf pine
Ponderosa pine
Monterey pine
16,000
(originally
360,000?
Most common soils
Inceptisols, Entisols, coarsegrained
Sandy Spodosols and
Entisols
Various, often rocky
Spodosols, Ultisols,
Entisols, needs water, int.
drainage
Rocky, often carbonates
Sandy, acidic, relatively
infertile, but occurs on many
soils
Various
Deep sandy loams, high
organics, acidic to very
acidic, clay pan beneath
65
83,000
(originally Sandy soils, mostly Entisols
Red pine
395,500) and Spodosols
Well-drained, sandy, low-to
Eastern white pine
medium quality
Torrey pine
EM
le
ea
v nAnnual
a mmean T
Mean
Jan
M
e
a
n
mMean Jul Abs min
Warm
season
(Apr-Sep) Snowfall
Abs max Ppt (mm) ppt (%)
(cm)
AET/PET
-5 to 8 -19 to -2
7 to 18 -20 to -50
26-30 300-1800
-8 to 7-30 to -4.5
-0.6 to 15 -11 to 6
11 to 22 -21 to -46
11 to 28
-35
29-38 250-1400
44 150-700
18 to 24
-2 to 14
8 to 19
-12 to 0
27 to 28
7 to 24
15-23 4 to 17
5-10 -15 to 15
25 to 28
8 to 26
-40
9 to 11
16 to 18
-5
-1 to 11 -22 to -1
-0.5 to 18
17.3
B&H
-18
14 to 24 -23 to -40
40-60
35-65
0.34 to 1
0.37 to 1
low 0.17 to 0.92
41 1100-1600
150-800
0.9 to 1
0.21 to 0.75
1100-1700
43 200-1100
30-75
41
380-890
10-30
none
0.538
32-38 500-1500
50-75
100-300
0.74 to 1
500-2300
251
50-70
15
13-254
none
0.62 to 1
0.318
-21 to 3
14 to 27
14 25 (26 Aug
22 and Sep)-2
B&H, USGS
B&H, USGS
B&H
10-60? 460-1270
42
B&H
B&H, USGS
B&H
0.87 to 1
0.21 to 0.99
B&H
USGS
Economics
Species
albicaulis
Variety
Common Name
Whitebark pine
banksiana
Jack pine
edulis
Pinyon pine
elliottii
longaeva
palustris
elliottii
Slash pine
Bristlecone pine
Longleaf pine
ponderosa scopulorumPonderosa pine
radiata
resinosa
Monterey pine
Red pine
strobus
torreyana
Eastern white pine
Torrey pine
Notes
Food
Timber
Other
not important
very important pulpwood,
increasingly used as construction
timber
important
firewood source
for native
Pine nuts not important
americans
fast growing, replacing
major world
longleaf pine due to
source of resin
economics
important, mostly pulp
and turpentine
not important
high quality
most important species in N.
America
most widely planted
pine in the world
very important outside of US, pulp
important (timber, pulpwood)
In1600s-1800s, highly
sought after for ship
building and
construction lumber
plantation tree in E US
not important
Where planted?
Aus, NZ, China, SA,
southern US
Aus, NZ, China, SA
Aus, NZ
Aus, NZ, SA, Spain, S.
America
N. USA and Canada
Europe
Social criteria
• Difficult to assess, requires direct interaction
with the public
• Surveying, polling, workshops
– Expensive, time-consuming and difficult to carry
out, but important!
• We are considering focusing on a group of
California conifers to make the pilot project
easier
Common Name
Whitebark pine
Jack pine
Pinyon pine
Slash pine
Bristlecone pine
Longleaf pine
Ponderosa pine
Assessment: Focal Impact
Split into empirical and normative scores
N
o
t Prob
Prob of
eextinction geog.
s(x3)
decline
6
1
1
1
5
3
1
P
r
o
b
e
x
t
i
Monterey pine
9
Red pine
MN state tree
1
Eastern white pine
4
Torrey pine
9
Indirect
Prob of
effect of
abunda
loss on
Empirical
nce
Financial community UniqueRevers Score
decline loss (x2) (x2)
ness (x3) ability (x2)
2
9
10
3.5
6
7
2
1.75
6
8
4
2.15
8
3
7
2.3
4
5
10
3.15
7
8
7
3
10
6
6
2.65
9
2
7
8
2
1
3
6
1
7
10
7
10
2.7
2.65
3.05
3.15
Equity
Cultural of
importan impac
ce of sp t
5
5
10
5
7
7
7
7
7
7
7
Violati
on of
biol.
Integrit
y
Bioce
ntric
consi
derati
ons
Normati
ve
Score
(x1)
Total
2.5 3.17
2.5 2.00
5 3.10
2.5 2.37
3.5 3.27
3.5 3.17
3.5 2.93
3.5
3.5
3.5
3.5
2.97
2.93
3.20
3.27
Normative issues add variance to the
assessment!
Theoretical differences between two
different groups of stakeholders
Assessment: Collateral Impact
Common Name
Whitebark pine
Jack pine
Pinyon pine
Slash pine
Bristlecone pine
Longleaf pine
Ponderosa pine
Monterey pine
Red pine
Eastern white pine
Torrey pine
Prob of
decline Prob of Empirical
of native loss of
Score
spp
ecol fx
(x2)
4
2
1.5
7
8
3.75
6
6
3
7
7
3.5
1
1
0.5
3
7
2.5
3
7
2.5
8
9
4.25
4
7
2.75
5
6
2.75
6
9
3.75
Societal/Cu
ltural
values
ranking
Prob of
direct
human
impact
Others?
1
1
1
1
1
1
1
1
1
1
1
Normative
Score (x1) Total 1-CI
1 1.33
3.67
1 2.83
2.17
1 2.33
2.67
1 2.67
2.33
1 0.67
4.33
1 2.00
3.00
1 2.00
3.00
1 3.17
1.83
1 2.17
2.83
1 2.17
2.83
1 2.83
2.17
Assessment: Feasibility
Sustainability
Availability
of MR
Ease of
of
Legal/re (necessity for
propagation appropriate Cost of gulatory long-term
Empirical
Common Name
/monitoring sites for MR MR
obstacles engagement) Score (x2)
Whitebark pine
2
7
10
3.17
Jack pine
9
10
10
4.83
Pinyon pine
3
10
10
3.83
Slash pine
8
8
10
4.33
Bristlecone pine
1
5
7
2.17
Longleaf pine
4
10
10
4.00
Ponderosa pine
6
10
10
4.33
Monterey pine
10
10
5
4.17
Red pine
5
10
10
4.17
Eastern white pine
7
10
10
4.50
Torrey pine
2
5
3
1.67
Spread of
collateral
impact
question
responses ?
Normative
Score (x1) Total
3.17
4.83
3.83
4.33
2.17
4.00
4.33
4.17
4.17
4.50
1.67
Assessment: Acceptability
Common Name
Whitebark pine
Jack pine
Pinyon pine
Slash pine
Bristlecone pine
Longleaf pine
Ponderosa pine
Monterey pine
Red pine
Eastern white pine
Torrey pine
concerns
degree
aesthetic re. land
willingness
willingness to societal of trust in /cultural/ use
to create
suffer
recogniti scientific moral
restrictions new
potentially
on of
opinion attitudes in
legal/regula
irreversible
need for re. need toward
recipient tory
Normative
consequences action
for MR
MR sp
area
framework Score
Total
7
3
2
2
7
7
5
9
7
6
10
Questions related to acceptability are all normative,
and will have high variance in the responses
3.5
1.5
1
1
3.5
3.5
2.5
4.5
3.5
3
5
California examples
Torrey pine
Focal Impact
5
4
3
2
1
Acceptability
0
Collateral Impact
Feasibility
Ponderosa pine
Focal Impact
5
4
3
2
1
Acceptability
0
Collateral Impact
Feasibility
Monterey pine
Focal Impact
5
4
3
2
1
Acceptability
0
Collateral Impact
Feasibility
Pinyon pine
Focal Impact
5
4
3
2
1
Acceptability
0
Collateral Impact
Feasibility
Whitebark pine
Focal Impact
5
4
3
2
1
Acceptability
0
Collateral Impact
Feasibility
Final thoughts
• From the biological side, invasiveness is a
major factor
• Predicted invasiveness is now available for
many tree taxa beyond the pines
• Taxa with high documented or predicted
invasiveness should probably not be relocated
outside of their range, and certainly not
without major analysis and safeguards
Predicted invasiveness, from discriminant function
based on seed mass, interval between large seed
crops, and minimum juvenile period
Richardson &
Rejmanek 2004
Diversity & Dists
Final thoughts
• Lack of sufficient biological and ecological
information is a major problem for most taxa
– We must be VERY careful with taxa we don’t
sufficiently understand
• But lack of information relating to ethical,
legal, policy, etc. issues is just as important
• Policy is needed to provide framework for
making MR decisions transparent and for
assessing public input, opinions, and other
normative questions
Key ecological ethics questions
• What is the most scientifically valid and ethically
defensible process for choosing candidate populations
for relocation (and selecting the recipient ecosystems)?
• Who should make MR decisions and carry out
particular managed relocations?
• How should we weigh the risks of accelerating
ecological harm or conducting unnecessary relocations
against the best available knowledge of present and
future conservation status?
• How should societal values surrounding particular
species and landscapes factor into the determination
of "objective need" under scientific MR assessments?
Minteer and Collins 2010 Ecol. Apps.
Key ecological ethics questions
• How can we ensure MR efforts do not undermine the
longstanding policy commitment to preserve ecological
integrity? Should integrity of ecosystems always be
prioritized over survival of individual species when
these goals conflict?
• Should we be concerned that MR, as an adaptive policy
response to climate change, will weaken our ethical
resolve to address root causes of climate change via
mitigation efforts (e.g., reducing global greenhouse gas
emissions)?
• Does a policy of MR demonstrate proper respect for
vulnerable species and ecosystems, or does it convey
an attitude of domination and control that clashes with
core conservation values, such as Aldo Leopold's (1949)
land ethic?
The final word
“The precautionary principle has been historically useful in
guiding conservation management, but global environmental
change presents a different sort of problem. There are real risks
of harm to biodiversity through inaction as well as action. The
only way forward to confront unprecedented problems such as
global anthropogenic climate change is careful risk analysis,
including an honest evaluation of uncertainty and potential harm,
along with broad public debate beyond the technical expertise of
scientists and managers. We must engage in careful study of
ethical, legal and biological issues surrounding the idea of
managed relocation even if the ultimate conclusion is that it is the
wrong approach to managing a difficult problem.”
Schwartz et al. TREE 2009