Modeling subalpine conifer response to climate change with
data from a warming experiment
Mountain Climate Conference, September 16, 2014
Erin Conlisk, Cristina Castanha, Andrew Moyes, Matt Germino, Lara Kueppers
UC Berkeley, UC Merced, and Lawrence Berkeley Lab
1
Highest abundance is typically at the center of a species range
2
Climate change could change abundances, but not range
3
Climate change could change range, but not overall abundance
4
Questions
How will conifer populations – abundances and range –
change with climate change?
How can we scale short-term, local, experimental
observations to whole populations?
5
Outline
• Alpine Treeline Warming Experiment background and
update
6
Outline
• Alpine Treeline Warming Experiment background and
update
• Experimental results: Engelmann spruce and limber
pine seedling survival with warming
7
Outline
• Alpine Treeline Warming Experiment background and
update
• Experimental results: Engelmann spruce and limber
pine seedling survival with warming
• Model leverages experimental results to forecast
future populations
0
0
0
0
0
 n1 (t + 1)   s1,1 (t )
 n (t + 1)   s (t )
0
0
0
0
0
  2,1
 2
0
0
0
0
 n3 (t + 1)   0
s3, 2 (t )
 

0
0
0
0
s4,3 (t )
 n4 (t + 1)   0
 n5 (t + 1)   0
0
0
0
s5, 4 (t ) s5,5 (t )
 

0
0
0
s6,5 (t ) s6,6 (t )
 n6 (t + 1)   0
=
  0

0
0
0
0
s7 ,6 (t )

 






 ns15 (t + 1)  
 n (t + 1)  0
0
0
0
0
0
 
 a16
0
0
0
0
0
 na17 (t + 1)  0
  






 

na 50 (t + 1)  0
0
0
0
0
0
 f16 (t )
f17 (t )

0
0

0
0

0
0

0
0

0
0



 s16,16 (t )
0
 s17 ,16 (t ) s17 ,17 (t )

0
s18,17 (t )




0
0
 f 49 (t )
f 50 (t )   n1 (t ) 

0
0   n2 (t ) 



0
0   n3 (t ) 



0
0   n4 (t ) 

0
0   n5 (t ) 



0
0   n6 (t ) 


   



0
0   ns15 (t )

0
0   na16 (t )




   na17 (t )


 s49, 49 (t )
0   
 s50, 49 (t ) s50,50 (t ) na 50 (t )
8
Outline
• Alpine Treeline Warming Experiment background and
update
• Experimental results: Engelmann spruce and limber
pine seedling survival with warming
• Model leverages experimental results to forecast
future populations
• Future modeling
0
0
0
0
0
 n1 (t + 1)   s1,1 (t )
 n (t + 1)   s (t )
0
0
0
0
0
  2,1
 2
0
0
0
0
 n3 (t + 1)   0
s3, 2 (t )
 

0
0
0
0
s4,3 (t )
 n4 (t + 1)   0
 n5 (t + 1)   0
0
0
0
s5, 4 (t ) s5,5 (t )
 

0
0
0
s6,5 (t ) s6,6 (t )
 n6 (t + 1)   0
=
  0

0
0
0
0
s7 ,6 (t )

 






 ns15 (t + 1)  
 n (t + 1)  0
0
0
0
0
0
 
 a16
0
0
0
0
0
 na17 (t + 1)  0
  






 

na 50 (t + 1)  0
0
0
0
0
0
 f16 (t )
f17 (t )

0
0

0
0

0
0

0
0

0
0



 s16,16 (t )
0
 s17 ,16 (t ) s17 ,17 (t )

0
s18,17 (t )




0
0
 f 49 (t )
f 50 (t )   n1 (t ) 

0
0   n2 (t ) 



0
0   n3 (t ) 



0
0   n4 (t ) 

0
0   n5 (t ) 



0
0   n6 (t ) 


   



0
0   ns15 (t )

0
0   na16 (t )




   na17 (t )


 s49, 49 (t )
0   
 s50, 49 (t ) s50,50 (t ) na 50 (t )
9
Outline
• Alpine Treeline Warming Experiment background
and update
• Experimental results: Engelmann spruce and limber
pine seedling survival with warming
• Model leverages experimental results to forecast
future populations
• Future modeling
0
0
0
0
0
 n1 (t + 1)   s1,1 (t )
 n (t + 1)   s (t )
0
0
0
0
0
  2,1
 2
0
0
0
0
 n3 (t + 1)   0
s3, 2 (t )
 

0
0
0
0
s4,3 (t )
 n4 (t + 1)   0
 n5 (t + 1)   0
0
0
0
s5, 4 (t ) s5,5 (t )
 

0
0
0
s6,5 (t ) s6,6 (t )
 n6 (t + 1)   0
=
  0

0
0
0
0
s7 ,6 (t )

 






 ns15 (t + 1)  
 n (t + 1)  0
0
0
0
0
0
 
 a16
0
0
0
0
0
 na17 (t + 1)  0
  






 

na 50 (t + 1)  0
0
0
0
0
0
 f16 (t )
f17 (t )

0
0

0
0

0
0

0
0

0
0



 s16,16 (t )
0
 s17 ,16 (t ) s17 ,17 (t )

0
s18,17 (t )




0
0
 f 49 (t )
f 50 (t )   n1 (t ) 

0
0   n2 (t ) 



0
0   n3 (t ) 



0
0   n4 (t ) 

0
0   n5 (t ) 



0
0   n6 (t ) 


   



0
0   ns15 (t )

0
0   na16 (t )




   na17 (t )


 s49, 49 (t )
0   
 s50, 49 (t ) s50,50 (t ) na 50 (t )
10
Alpine, 3540 m
Treeline, 3430 m
Forest, 3060 m
Figure: Andrew Moyes
11
Alpine, 3540 m
Treeline, 3430 m
Control
Heated
Watered (2.5 mm/wk)
Heated-Watered
Forest, 3060 m
Figure: Andrew Moyes
12
3m
2m
Alpine, 3540 m
IR Heater
Treeline, 3430 m
Control
Heated
Watered (2.5 mm/wk)
Heated-Watered
Forest, 3060 m
Figure: Andrew Moyes
13
3m
Engel. Engel.
spruce spruce
2m
Limber Limber
pine
pine
Alpine, 3540 m
IR Heater
Soil moist. and temp.
Treeline, 3430 m
Control
Heated
Watered (2.5 mm/wk)
Heated-Watered
First seeds were sown in Fall 2009.
Forest, 3060 m
Figure: Andrew Moyes
14
Alpine, 3540 m
Treeline, 3430 m
Photos: Andrew Moyes
Subalpine forest, 3060 m
15
Plot difference in
temperature compared to
daily control average (oC)
Experimental treatments: temperature and moisture
Alpine, Control
More observations
Fewer observations
Plot difference in
volumetric water
content compared to
daily control average
Figure: Andrew Moyes
16
Plot difference in
temperature compared to
daily control average (oC)
Experimental treatments: temperature and moisture
Alpine, Control
More observations
Fewer observations
Plot difference in
volumetric water
content compared to
daily control average
Figure: Andrew Moyes
17
Plot difference in temperature compared to
daily control average (oC)
Control plots show no moisture or temperature differences
More observations
Alpine
Fewer observations
Treeline
Forest
Plot difference in volumetric water content
compared to daily control average
Figure: Andrew Moyes
18
Alpine
Plot difference in temperature compared to
daily control average (oC)
Heating treatments are strongest at forested site
Treeline
Forest
Plot difference in volumetric water content compared to daily control average
Figure: Andrew Moyes
19
Photo: Cristina Castanha
20
Observed changes in Engelmann spruce and
limber pine recruitment with experimental warming
21
At forest site, heating is particularly detrimental
Engelmann spruce
Roughly 29,000 seeds were sown from 2009-2013
Germination and First-Year Survival
0.05
0.025
Forest
Photo: Glenn F. Cowan
9 weeks
0
1 cm
Photo: Cristina Castanha
Control Water
Heat
Heatwater
22
At all sites, watering is beneficial
0.025
0
0.05
Treeline
0.025
0
0.05
Forest
9 weeks
Alpine
Photo: Glenn F. Cowan
Roughly 29,000 seeds were sown from 2009-2013
Germination and First-Year Survival
Engelmann spruce
0.05
0.025
0
1 cm
Photo: Cristina Castanha
Control Water
Heat
Heatwater
23
After first year, year-to-year survival is less sensitive
1
Engelmann spruce
0.8
Alpine
0.6
0.4
0
1
0.8
Treeline
Annual Survival
0.2
0.6
0.4
0.2
0
1
0.8
Photo: Glenn F. Cowan
9 weeks
0.6
0.4
0.2
Forest
Year 0-1
Year 1-2
Year 2-3
0
1 cm
Photo: Cristina Castanha
Control Water
Heat
Heatwater
24
Limber pine shows similar results to spruce
0.2
Roughly 16,000 seeds were sown from 2009-2013
Alpine
0.1
0
0.3
Treeline
0.2
0.1
0
0.2
Forest
Germination and First-Year Survival
Limber pine
0.1
9 weeks
1 cm
0
Photo: Cristina Castanha
Control Water
Heat
Heatwater
25
Overall higher survival in limber pine than spruce
1
Limber pine
0.8
Alpine
0.6
0.4
0
1
0.8
Treeline
Annual Survival
0.2
0.6
0.4
0.2
0
1
0.6
Forest
0.8
Year 0-1
Year 1-2
Year 2-3
0.4
0.2
9 weeks
0
1 cm
Photo: Cristina Castanha
Control Water
Heat
Heatwater
26
Models forecasting populations using the experimental
recruitment changes under climate manipulations
27
Photo: Jeffry Mitton
Population model
Alpine
6 ha
Initially no individuals,
relies on dispersal from
treeline site
Treeline
Initially few adult trees,
mostly large saplings
Forest
Initially many adult trees
28
Vital rates: only ATWE data changes between sites
Stage-based matrix model
0
0
0
0
0
 n1 (t + 1)   s1,1 (t )
 n (t + 1)   s (t )
0
0
0
0
0
 2
  2,1
 n3 (t + 1)   0
0
0
0
0
s3, 2 (t )

 
0
0
0
0
s4,3 (t )
 n4 (t + 1)   0
 n5 (t + 1)   0
0
0
0
s5, 4 (t ) s5,5 (t )

 
0
0
0
s6,5 (t ) s6, 6 (t )
 n6 (t + 1)   0
=


0
0
0
0
0
s7 , 6 (t )


 





 ns15 (t + 1)  
 n (t + 1)  0
0
0
0
0
0
 a16
 
0
0
0
0
0
 na17 (t + 1)  0

 






  
na 50 (t + 1)  0
0
0
0
0
0
ATWE Data
f17 (t )
0


f16 (t )
0

f 49 (t )
0

0
0

0

0
0

0



0
0
0
0

0




 s16,16 (t )
0
 s17 ,16 (t ) s17 ,17 (t )

0
s18,17 (t )




0
Literature
0




0

0
0

 s49, 49 (t )
 s50, 49 (t )
f 50 (t )   n1 (t ) 
0   n2 (t ) 


0   n3 (t ) 


0   n4 (t ) 
0   n5 (t ) 


0   n6 (t ) 
   


0   ns15 (t )
0   na16 (t )


   na17 (t )


0   
s50,50 (t ) na 50 (t )
Smith and Veblen
Ave. annual
survival
1
0.995
Eng. spruce
Limber pine
0.99
0.985
4
14
24
dbh (cm)
34
44
Above this
dbh all trees
are in the
upper canopy
29
Population model results – Engelmann spruce
Abundance of trees dbh≥4cm in 6 ha
30,000
Treeline – Engelmann spruce
20,000
10,000
0
0
100
200
300
Time (years)
400
500
30
Population model results – Engelmann spruce
Abundance of trees dbh≥4cm in 6 ha
30,000
Treeline – Engelmann spruce
20,000
Heating is phased
in over 100 years
10,000
0
0
100
200
300
Time (years)
400
500
31
Population model results – Engelmann spruce
Abundance of trees dbh≥4cm in 6 ha
30,000
Treeline – Engelmann spruce
20,000
10,000
0
0
100
200
300
Time (years)
400
500
32
Population model results – Engelmann spruce
Abundance of trees dbh≥4 cm in 6 ha
1,200
Forest – Engelmann spruce
1,000
Population is almost
entirely old growth trees.
800
600
400
200
0
0
100
200
300
Time (years)
400
500
33
Population model results – Engelmann spruce
Abundance of trees dbh≥4 cm in 6 ha
0.4
Alpine – Engelmann spruce –
dispersal = 0.1%
0.3
0.2
0.1
0
0
100
200
300
Time (years)
400
500
34
Population model results – Limber pine
Abundance of trees dbh ≥ 4 cm in 6 ha
20,000
Treeline – Limber Pine
15,000
10,000
5,000
0
0
100
200
300
Time (years)
400
500
35
Population model results – Limber pine
6,000
Abundance of trees dbh ≥ 4 cm in 6 ha
Forest – Limber Pine
4,000
2,000
0
0
100
200
300
Time (years)
400
500
36
Population model results – Limber pine
Abundance of trees dbh ≥ 4 cm in 6 ha
2.5
Alpine – Limber pine – dispersal =
0.1%
2
1.5
1
0.5
0
0
100
200
300
Time (years)
400
500
37
Conclusions
• Heating is overall bad at all sites, especially for first
year of a tree’s life
38
Conclusions
• Heating is overall bad at all sites, especially for first
year of a tree’s life
39
Conclusions
• Heating is overall bad at all sites, especially for first
year of a tree’s life
• Watering is overall good at all sites
• Lots of inter-annual variability
• Differences among treatments and sites were sufficient
to cause big changes in overall population size
• Dispersal from adjacent sites can mitigate the impact
of declining populations
• Future modeling should consider regional changes
40
Future Models
Photo: Jeffry Mitton
41
Next steps
• Ignore treatments, instead record climate in each plot
• Find a relationship between survival and climate
Survival (year 0-1)
0.3
0.75
Engelmann spruce
Control
Watered
Heated
Heat-watered
0.2
0.5
0.1
0.25
0
0
100
150
200
250
Limber pine
300
100
150
Growing season length (days)
200
250
300
42
Next steps
• Ignore treatments, instead record climate in each plot
• Find a relationship between survival and climate
• Using climate predictions, create a regional population model
Survival (year 0-1)
0.3
Engelmann spruce
Control
Watered
Heated
Heat-watered
0.2
0.1
0
100
150
200
250
300
Growing season length (days)
43
Thanks
• All field crews 2008-2014
• Jeremy Smith and Thomas Veblen for sharing tree data
• Department of Energy Program Office of Science,
Terrestrial Ecosystems Science Program
• University of Colorado Mountain Research Station
• Niwot Ridge LTER
44