Relationships between common
garden responses and climate in
big sagebrush
Bryce Richardson, USDA-FS, RMRS-Provo
Nancy Shaw, USDA-FS, RMRS-Boise
Matthew Germino, USGS, FRESC-Boise
Shannon Still, Chicago Botanic Garden
Outline
 Big sagebrush common garden study design and
climates
 Comparison of mortality among gardens and
subspecies
 Associate population mortality to climate of the seed
source (create a genetic model)
 Overlay genetic model onto a species distribution of
wyoming big sagebrush
 Discuss seed zone strategies
Common garden study design
 3 common gardens – planted spring 2010




Ephraim, UT (Snow Field Station)
Majors Flat, UT (Ephraim Canyon)
Orchard, ID (east of Boise)
50 source populations
 25 A. tridentata tridentata (2X and 4X)
 13 A. tridentata wyomingensis (4X)
 12 A. tridentata vaseyana (2X and 4X)
 ~10 plants per source at each garden (465 plants
per garden)
Common garden attributes: 3year climate averages 2011-2013
Garden
Elev (m)
MTCM
oC
MTWM
oC
MAP (in)
TDIFF
Ephraim, UT
1690
-9.7*
21.2
10.9
30.9
Majors, UT
2105
-4.7*
20.8
na
25.5
Orchard, ID
974
-2.9
25.0
10.1
27.9
Ephraim
Majors
Orchard
The influence of terrain on climate
Global Change Biology
Volume 17, Issue 2, pages 1022-1035, 24 MAY 2010 DOI: 10.1111/j.1365-2486.2010.02263.x
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2010.02263.x/full#f1
Ephraim and Majors climate comparison
Monthly moving average minimum temperatures (2011 to 2013) for
Ephraim and Majors, UT
 Bottom line: Ephraim experiences large swings
between summer and winter temperatures
Mortality among gardens
Fall 2013:
 Ephraim: 53%
 Majors: 3.6%
 Orchard: 14%
Mortality by subspecies
• Vasey has significantly higher mortality at each garden (p< 0.001)
• Ephraim: each subspecies had at least one population with 100% and
0% mortality
Mortality-climate analyses
 37 climate variables involving temperature, moisture or
interactions
 Climate variables derived source population locations
using a gridded (1 km) climate surfaces
 Regression analyses of mortality and climate performed
at the species and subspecies level
2013 Mortality-climate relationship
positively correlated with
warmer winter temperatures
( r = 0.41)
 Similar slopes, but different
intercepts among subspecies
Inc Mortality
 Species level: mortality
Warmer winters
Mortality-climate by subspecies
Subpecies
n
Climate model
Fit (r)
p-value
Basin
25
tdiff (mtwm-mtcm)
-0.54
0.005
Vasey
12
map x mtcm
0.91
<0.0001
Wyoming
13
dd5 x mtcm
0.73
0.005
Regression of climate and subspecies
mortality
Less temp extremes
Wyoming
Inc Mortality
Plants from more continental climates (greater
summer-winter temperature differences) had
increased survivorship at Ephraim
Focus on wyoming big sagebrush
• Management importance
•
•
•
•
Most abundant and widespread
Sage grouse habitat
Mitigate cheatgrass invasion
Greater impact from climate change
• More conducive to SDM
modeling
• Vasey dependent on slope and
aspect
• Basin dependent on soil depth
• Attributes not suitable to modeling
because variability below the 1km2
spatial scale
Wikipedia.org
Bioclimate model of
Wyoming big sagebrush
• Dark blue higher probability
• >100 presence points and >
1000 absences
• Blackbrush
• Mtn Mahogany
• Gamble Oak?
• CA chaparral community
• A work in progress
• Omission error in plains
• Comission in CA
-125°
-120°
-115°
-110°
-105°
50°
45°
45°
40°
40°
35°
35°
30°
55tga.me
Artemisia_tridentata_tetraploids.current.s61.55tga.me.tif
<VALUE>
0
110 220
440 Kilometers
0 - 0.087325081
0.087325081 - 0.258178501
-115°
-110°
0.258178501 - 0.463202605
-105°
0.463202605 - 0.691007165
0.691007165 - 0.964372637
-100°
Wyoming big sagebrush genetic
model
-130°
-125°
-120°
-115°
-110°
-105°
50°
45°
45°
40°
40°
35°
mortality = 0.98853 + (dd5mtcm * 0.04378)
35°
Blue: likely to survive at Ephraim
Orange to yellow: more likely to die
30°
0
105 210
-120°
420 Kilometers
-115°
-110°
-105°
Classifying zones
-110°
-105°
 Example: 3 Montana
population
 Color shades = intervals
of 10% predicted
mortality
 MTW-2: 0%
 MTW-1: 28%
 MTW-3: 50%
MTW-2
MTW-3
45°
MTW-1
45°
0 37.5 75
150 Kilometers
-110°
-105°
Preliminary zones – two strategies
 7 seed zones (~20%
 11 seed zones (~10%
mortality rate interval)
-125°
-120°
-115°
-110°
mortality rate interval)
-105°
-125°
-120°
-115°
-110°
50°
45°
-105°
50°
45°
45°
45°
40°
40°
40°
40°
35°
35°
5 seed zones
3 seed zones
In Great Basin
30° 0
-120°
95 190
30° 0
380 Kilometers
-115°
35°
35°
-110°
-105°
-120°
95 190
380 Kilometers
-115°
-110°
-105°
Caveats and other considerations
 Caveats:
 The common garden evaluated juvenile and adult
plant responses – not seed and seedling
establishment and viability
 Other traits not taken into account
 Flower phenology
 Growth
 Seed yield
Summary
 Adjacent Ephraim and Majors common gardens have
dramatically different climates
 These climates appear to have affected mortality rates
and the patterns among populations
 Regression of climate and mortality corroborates these
observations, suggesting big sagebrush is principally
adapted to the interaction between winter and summer
temperatures
 Seed zones: recommend the 11 zone model
 Analyze and incorporate the other common garden data
 Don’t move seed more that 5o in latitude.
Acknowledgements
 Technical assistance: Stephanie Carlson, Alexis
Malcomb, Matt Fisk, Erin Denney, Jan Gurr, Utah DNR,
and numerous plant material collectors,
 Funding: GBNPP, USFS National Fire Plan, Great
Basin LCC