Varying temporal scale of climate control of flowering
at high elevation in the Colorado Rocky Mountains
The Rocky Mountain Biological Laboratory
Mean snowfall (since 1975) = 10.9 m
Range = 4.7 – 16.4 m
1800
Winter Snowfall in Gothic
1600
Snowfall (cm)
1400
1200
1000
800
600
400
200
0
1975
1980
1985
1990
1995
2000
2005
2010
Mean minimum April temperature (°F)
26
24
22
20
18
16
14
12
10
r2 = .178, p = .007
8
1975
1980
1985
1990
1995
2000
2005
2010
Was also forecast for:
Montrose, CO
Grand Junction, CO
Gunnison, CO
Aspen, CO
Telluride, CO
Rifle, CO
Cahone, CO
Dove Creek, CO
Cisco, UT
Thompson, UT
Moab, UT
Bluff, UT
Mexican Water, AZ
First Date of Bare Ground (Day of Year)
180
Gothic Snow Data (from billy barr)
6/19/95
170
160
150
140
130
120
110
4/26/77
1975
1980
4/25/02
1985
1990
1995
2000
2005
4/23/12
2010
2015
Day of year of peak flow, East River at Almont
29 June
180
170
160
150
140
130
7 May
120
1940
1960
1980
2000
170
Mean day of year of first flower
r2 = .681
p < .001
Claytonia lanceolata
14 June
160
150
140
130
120
24 April
110
20 April 110
120
130
140
150
Day of year of bare ground
160
170
19 June
200
Date of first flower
190
180
170
160
Cardamine cordifolia
150
140
1970
1980
1990
2000
2010
Number of flowers and plants in bloom
30
Summer rain can produce a second flowering period
Androsace septentrionalis, plot WM5, 1997
25
20
15
10
5
0
6/16
Date vs. Flowers
Date vs. Plants
6/30
7/14
7/28
Date
8/11
8/25
Frasera speciosa (Gentianaceae)
Frasera
speciosa
(Gentianaceae)
being visited
by Bombus
flavifrons.
Cumberland Pass, 12,300 ft.
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
Rec.
G
G
2
2
2
2
2
2
2
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2
2
2
2
2
2
2
2
2
2
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2
4
2
2
2
2
2
2
2
2
2012
2013
2014
2015
2016
2017
?
4
2018
2019
2020
2021
The history of Frasera plant #911
Frasera plant #911 in 2011; a seedling in 1982
Frasera speciosa flowering in the East River Valley
18000
Number of flowering plants
16000
14000
12000
10000
?
?
?
8000
6000
4000
2000
0
1970
1980
1990
2000
2010
What triggers the mast flowering events in Frasera speciosa?
Frasera speciosa flowering in East River valley
N = 8 years with > 1,700 flower stalks (1980-2010)
0.8
r
2
0.6
0.4
0.2
0.0
0
1
2
3
4
5
6
Number of years lag for precipitation before mast flowering
7
East River valley Frasera speciosa
Number of flowering plants
20000
2
r = .747
P < .003
18000
16000
14000
1961
1969
12000
10000
1973
8000
1951
6000
4000
1977
2000
0
4
6
8
10
12
14
16
July + August precipitation 4 years previous (cm)
18
Where else did Frasera speciosa flower in 2010?
Wasatch Mountains in Utah (Tony Frates, Jonathan Coop, Zak Gezon, and
Wayne Padgett, pers. comm.)
San Pitch Mountains in Utah (Matthew Meccariello, pers. comm.)
Colorado Plateau in southern Utah (Ben Everitt, pers. comm.)
Sandia Mountains in New Mexico (Dana M. Price, George Miller, and Vera
Norwood, pers. comm.)
Lemhi Mountain Range in Idaho (Wendy Jo Hoffman, pers. comm.)
San Juan Mountains in Colorado (Al Schneider, Amanda Kuenzi, Steve
Traudt, Joe Ceredini, and Priscilla Sherman, pers. comm.)
East River valley Frasera flowering
Years with > 1,000 flower stalks
20000
r2 = .747, p = .003
Number of flowering plants
18000
1996
2010
1988
16000
14000
1969
1961
12000
10000
2003
2005
1990
2014
8000
1973
1980
2016
6000
4000
1977
2000
1983
1992
0
6
8
10
12
14
16
July + August rain, four years before flowering (cm)
18
East River valley Frasera flowering
Years with > 1,000 flower stalks
20000
r2 = .717, p = .004
Number of flowering plants
18000
1996
2010
1988
16000
14000
1969
1961
12000
10000
2003
2005
1990
2014
8000
1973
1980
2016
6000
4000
1977
2014
2000
1983
1992
0
6
8
10
12
14
16
July + August rain, four years before flowering (cm)
18
Polygonum
viviparum
Veratrum tenuipetalum (Melanthiaceae)
Ramets flowering (of 1,000 counted)
Is there an environmental cue that triggers Veratrum flowering?
600
500
East side plot
400
West side plot
300
* = watered
200
100
0
1985
1990
1995 * * 2000
2005
2010
Yes!
A cool summer: mean 49.8° in June 2009 (mean = 51.3°)
mean 56.5° in July 2009 (mean = 57.0°)
Wait another year for preformation: 2010
Then a flowering year: 2011
Is there an effect of climate change?
Environmental conditions were conducive to flowering
in 21.6% of the years from 1928-1983 compared to
14.8% from 1984 to 2010.
Helianthella quinquenervis
13 June 2001
21.55 (F)
-5.81 (C)
11 June 2004
25.07° F, -3.9° C
Number of aspen sunflower heads
3500
lower plot
upper plot
3000
2500
2000
1500
1000
500
0
1976 1980 1984 1988 1992 1996 2000 2004 2008 2012
6-year running segments
Peak flow in East River at Almont (cfs)
4000
3500
3000
2500
2000
1500
1000
500
0
1940
1950
1960
1970
1980
1990
2000
2010
Peak flow in East River at Almont (cfs)
6000
5000
4000
3000
2000
1000
0
1940
1950
1960
1970
1980
1990
2000
2010
Evolution of decadal and multidecadal
signals in precipitation (thick lines) in
(a) northern California (winter), (b) the
central Rocky Mountains (autumn), (c)
Minnesota (winter), and (d) eastern
Québec (annual). The thin lines
illustrate the original seasonal
precipitation record for each region.
The decadal component of autumn
precipitation over the central Rocky
Mountains operates on a 12–14-yr time
scale. Over the last 40 yr, this
component has been roughly in phase
with the northern California pattern but
this correspondence was not present
before 1960.
Ault & St. George 2010
Delphinium nuttallianum - 8 yr intervals
Mean day of year of first flower
190
180
170
160
150
140
130
1975
1980
1985
1990
1995
2000
2005
2010
7-year running intervals, Delphinium nuttallianum
Peak number of flowers
1000
800
600
400
200
0
1970
1975
1980
1985
1990
1995
2000
2005
2010
This summer – radio transmitters on hummingbirds
Conclusions
• Mountain environment is highly variable and changing
• Snowmelt dates are earlier, but frost dates are not
• Climate effects on phenology are driven almost entirely
by snowmelt date
• Flowering abundance can be driven by climate effects
with no lag, 2-year lag, or 4-year lag
• Unknown climate drivers are generating decadal cycles,
necessitating decades-long studies to study their effects