Above-treeline Linanthus pungens shrub-chronologies on the eastern Sierra Nevada
crest, Mono Co., California contain records of precipitation and temperature
Rebecca Franklin, Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, USA
4. Barney Lake Chronology Description
6. Climate-Growth Response
10 mi.
Barney Lake Linanthus pungens
chronology
N
A. BLRG Residual EPS, SSS value, .85 cut-off and sample depth
1
100
0.9
0.8
Here I present the first shrub-ring chronology
for L. pungens in North America. In panel B is
the L. pungens residual index values in black
with the +/- 1 SD levels shaded in gray. EPS
values for the Barney Lake site chronology
reach 0.85 (for a sample depth of 16) only after
1952 so I truncate the chronology there and
use only 1952-2007 index values in my
correlations and response functions.
To study recent (past 100 years) climate
and ecological change in the alpine Eastern
Sierra Nevada I utilize the ring width
patterns archived in the taproots of woody
shrubs growing above treeline.
~37.5N lat., 119W long.
14
250
60
0.5
BLRG res SSS
0.4
0.3
BLRG res EPS
0.2
6
150
4
2
100
0
0.1
50
2
1940
1.8
1950
1960
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
1980
1990
2000
0.4
0
1930
1940
1950
1960
1970
1980
1990
2000
Barney Lake Rock Glacier
Non-Rock
Glacier site
By Aspect
BLRG Site
Chronology
2. Barney Lake Rock Glacier Botany and Wood Anatomy
Average
Maximum Age
Species
Asteraceae
Antennaria
rosea
Asteraceae
Circium
scaciosum
Asteraceae
Ericameria
discoidea
70 years
Asteraceae
Ericameria
suffruticosa
70 years
Asteraceae
Erigeron
pygmaus
Asteraceae
Erigeron
compositus
Asteraceae
Solidago
multiradiata
Brassicaceae
Arabis
lemmonnii
Brassicaceae
Erysimum
capitatum var. perenne
Caryophyllaceae
Arenaria
kingii
Caryophyllaceae
Silene
sargentia
Grossulariaceae
Ribes
cereum
Hydrophyllaceae
Phacelia
hastata ssp. compacta
Lamiaceae
Monardella
odoratissima
Onagraceae
Castilleja
nana
Onagraceae
Castilleja
appellgatia
Polemoniaceae
Linanthus
pungens
120 years
Polemoniaceae
Phlox
diffusa
40 years
Polygonaceae
Eriogonum
ovalafolium
Polygonaceae
Eriogonum
incanum
Primulaceae
Primula
suffretescens
Pteridaceae
Athyrium
alpestre
Pteridaceae
Pellaea
brewerii
Ranunculaceae
Aquilegia
pubescens
Rosaceae
Holodiscus
microphyllus
Salicaceae
Salix
spp
Selaginellaceae
Selaginella
watsonii
90
60
20
Level ground
230
Chronology length
1895-2007
1931-2007
1934-2007
1928-2007
1930-2007
1895-2007
Number of Years
112
76
73
79
77
112
Year EPS > 0.85
1954
1948
1986
1962
1963
1959
Average sample length
49
49
43
46
45
71
Sample size (# plants)
95
39
22
27
19
9
Mean Ring Width (mm)
0.093
0.087
0.101
0.093
0.087
0.108
Standard Deviation
0.18
0.15
0.16
0.17
0.29
0.26
Mean
0.979
0.992
0.985
0.973
0.9853
0.992
Standard deviation
0.138
0.148
0.163
0.167
0.2529
0.256
Signal to Noise Ratio
7.049
6.642
2.862
2.361
2.111
4.685
RBAR
0.234
0.315
0.156
0.239
0.258
0.539
Mean Sensitivity
0.160
0.140
0.152
0.140
0.2048
0.202
Auto-correlation
0.296
0.221
0.283
0.398
0.4848
0.561
Standardized Chronology
14 years
10 years
Thin section images of the five most common woody shrubs at BLRG site. Scale is 1 mm.
a) Ericameria discolor, b) Linanthus pungens, c) Monardella odoritissima, d) Phlox diffusa, e) Salix
spp. These species are long lived and due to completely lignified taproots have potential for high
elevation dendrochronological studies. Linanthus pungens, is particularly long-lived, does not
suffer from root-rot and has exceptionally clearly demarcated growth rings.
BLRG Chronology
Statistics.
0
Residual
Standardized
Ring Width
-0.29
-0.23
-0.35
50
50
50
< 0.05
< 0.10
< 0.02
-0.2
-0.4
Residual
Standardized
Ring Width
-0.25
-0.25
-0.18
54
54
54
< 0.10
< 0.10
< 0.20
SWE
-0.6
-0.8
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
April SWE relative value (deciles) 1927 - 2007
Drought and snowpack variability as controls on Barney Lake L. pungens chronologies.
Initial correlations with a drought metric (Palmer Drought Severity Index, PDSI) and snowpack metric (April Snow Water
Equivalent) were significant but did not prove to be stable predictors of growth over time.
To account for this relationship between shrub ring growth and snowpack I sorted years of April SWE (Tioga Pass) into deciles
and regressed each of the ten deciles against ring width growth for the same years (Figure A). Both the highest deciles for SWE
and the lowest decile for SWE were highly (r= .9 - .8) negatively correlated with ring width growth for those years (p < 0.05).
C
B
For all raw ring width chronologies there is
an increasing trend in ring width I the latter
half of the 20th century. This is likely due to
the occurrence of younger individuals later
in the chronology as the trend is not seen
in the standardized chronology
25 years
Photo: C. Millar, 2007
Photo: C. Millar, 2007
1983 +1986:
record snowpack
5. Climate Station and Data Issues
A. Stability of Climate relationships over time
Climate Station
N
Bodie
Lee Vining
Gem Lake
Mammoth Lakes RS
Yosemite South Entr
Linanthus pungens (Torr.) Torr. ex Nutt. Commonly known as Granite Gilia or
Prickly Phlox, this species is in the Polemoniaceae family. It can achieve ages of
120 years at high elevations in the mountainous west. It’s distribution is
throughout the western United States and into southwest Canada.
It occupies dry rocky and sandy sites from 1000 – 3500 m.a.s.l. Its leaves are
alternate palmately lobed, 5-9 lobes and spiny-tipped.
0.8
0.7
0.6
0.5
0.4
0.3
4
5
6
Number of Radii included in Ring Width Measurement
7
x
B. Climate Station Chart
A. Climate Station Map
Yosemite Park HQ
0.9
Temperature and precipitation
values were taken from the
PRISM data set for latitude
37.56491N and longitude
118.9701 W.
Temperature and precipitation
values for all weather stations
in the Sierra Nevada range
were not significantly
correlated with the Barney
Lake chronology
In high elevation areas there is a paucity of climate stations. In the central Sierra Nevada there are 17 climate stations at mid- to high elevations
yet virtually all have incomplete records and missing data that makes them unsuitable for use in climate reconstruction and temperature monitoring
in rapidly changing, climatically sensitive areas. In the figures below I show the distribution of climate stations and the lack of complete records for
this area. This underscores the importance of above-treeline studies such as this one for the study of alpine ecosystems
1990, 1991:
Drought
1995: rcrd
snowpack
Correlations generated for the
Barney Lake chronology using
DendroClim2002 were
significant only for previous
winter’s precipitation (Oct-Jan)
and the current growing
season’s (June/July)
temperature, Tmax and Tmin.
Response functions significant
at the 95% confidence level
were only found for July
temperatue (Tmin and Tmax)
x
Ellery Lake
Circuit Uniformity and ring
width measurement in L.
pungens. Sub-shrubs used in
dendrochronological applications
usually have poorer circuit
uniformity that tree species. How
many radii are necessary to
measure to accurately
approximate annual growth
increment? For a sample size of
11 individuals I found that taking
more than three radii did not
increase accuracy of annual
growth increment measurement.
Tmax correlations significant at 95% confidence level
Photo: C. Millar, 2007
Distinct rock glacier microsites. BLRG has many discrete patches of
surface that support distinct species compositions. A) woody shrubs
Ericameria spp, B) Phlox diffusa, C) Primula suffretescens
1976 Record
cold summer
1977: drought
Precip correlations significant at 95% confidence level
Elevation
Temp
Snow
Ppt
BODIE
2551
1964-2010
1964-2010
1964-2010
LUNDY LAKE
2367
1931-1940
1931-1940
1931-1940
MONO LAKE/LEE VINING
2000
1950-2010
1950-2010
1950-2010
ELLERY LAKE
2940
1931-1949
1931-1965, 1982-2010
1931-2010
GEM LAKE
2734
1931-1950
1931-1950, 1981-2010
1931-2010 (no 51-54)
YOSEMITE PARK HQ
1225
1931-2010
1931-2010
1931-2010
MAMMOTH LAKES RS
2379
1993-2010
1994-2010
1994-2010
YOSEMITE SOUTH ENTR.
1538
1941-2010
1941-2010
1941-2010
LAKE SABRINA
2763
1931-1949
1931-1948, 1988-2010
1931-1948, 1988-2010
BIG CREEK PH 1
1487
1931-1962, 1999-2010
1931-1962, 1999-2010
1931-1962, 1999-2010
ASPENDELL
2591
1931-1941, 2002-2010
1931-1941, 2002-2010
1931-1941, 2002-2010
BISHOP CREEK INTAKE
2485
-
1982-2010
1959-2010
HUNTINGTON LAKE
2140
1931-2010
1931-2010
1931-1962, 1974-2010
SOUTH LAKE
2920
1931-1948
1931-1948, 1988-2010
1931-1948, 1975-2010
GRANT GROVE
2012
1940-2010
1940-2010
1940-2010
LODGEPOLE
2053
1968-2010
1951-1955, 1968-2010
1951-1955, 1968-2010
GIANT FOREST
1955
1931-1968
1931-1968
1931-1968
A. Climate Station Map:
Huntington Lake
Big Creek PH
Aspendell
Bishop Creek Intake
GREEN TEXT:
Low elevation Temperature and Precipitation data available for full record
Lake Sabrina
South Lake
RED TEXT:
High elevation Temperature and Precipitation data available for full record
(Black text indicates missing data, short period of record)
Period
April SWE
Correl
df
p
Correl
PDSI
df
p
correl
pNov Ppt
df
p
July avg T
Correl
df
p
1952-1979
-0.0493
26
--
-0.0290
26
--
-0.2964
26
< 0.05
0.4164
26
< 0.025
1980-2007
-0.5460
26
< 0.005
-0.5070
23
< 0.025
-0.3675
26
< 0.05
0.3676
26
< 0.05
Stability of Climate-growth Relationships over Time.
To test the stability of potential regression models, the
chronology was divided into calibration and verification
periods: 1952-1979 and 1980-2007.
Both April SWE and PDSI correlations with the Barney Lake
chronology were not stable over the full chronology length.
Correlations with both the previous year’s November
precipitation and the current growing year’s July temperature
(Tmax and Tmin) were stable over time. However, even
though the correlations are significant, the R2 values are low
as can be seen in panel B to the right.
The value of the “reconstructions” is limited, obviously, by the
fact that the chronology length does not extend further back in
time than the actual PRISM climate variables.
B. “Reconstructions”
25
Avg July Temperature (C)
A
T min correlations significant at 95% confidence level
x
Mono Lake
Average Correlation between RW and
BAI
p-value
PDSI
0.2
PDO correlations significant at 95% confidence level
Comparison of raw ring width
chronologies for 4 aspects at the
Barney Lake site. A) 90 degrees, b) 60
degrees, c) 25 degrees, d) level ground/no
aspect and e) 270 degrees. Chronologies
a through d are located on the Barney
Rock Glacier and site e is on the Barney
Lake non-rock glacier paired site.
Lundy Lake
3
Site statistics are listed for
microsite chronologies
sorted by aspect (90 deg.,
60 deg., 20 deg., no aspect,
and 230 deg.) and are also
sorted by full site
chronology vs. non-rock
glacier paired site and raw
ring widths vs. standardized
chronology.
df
p < .05
23
21
19
17
Actual Avg July T
Reconstructed Avg July T
pNovember Precipitation (mm)
45 years
1961: Drought
2
p < .05
Correlation
100+ years
3. Linanthus pungens: species selection, and cross-dating
1
Variable BLRG chronology
0.4
Correlation and Response Functions: PDO, PRISM Tmax, Tmin & Precipitation values
Species composition of BLRG. I catalogued 27
species growing on the rock glacier. Nine of the
species in particular had long-lived persistent
taproots with annual growth bands contained
therein.
0
B. Snowpack and Drought: correlations with BL Chronology
A. Ranked April SWE correlations with Barney Lake Chronology
Raw Ring Widths
Family
2010
0.6
Dec
2010
B. Barney Lake Rock Glacier Residual Index +/- 1 SD
0.2
-6
Mar
1970
0.6
-4
0
1
0.8
1
Subsample signal strength, EPS values and
sample depth are presented in panel A.
1934: drought
1.2
Wide annual rings occur during
drought years. L. pungens
inhabits dry cool (north-facing)
0.6
rocky sites and is not limited (as
indicated by this study) by
1983 & 1986: heavy snowfall
0.4
moisture. Narrow rings occur
accompanying record snow pack
1930
1940
1950
1960
1970
1980
1990
2000
and cool growing season
temperatures. This could be as a
result of the mechanics of being covered by snow pack and unable to photosynthesize or from cool growing season temperatures.
0
-2
Feb
20
1.4
BLRG sample depth
0.8
8
200
Jan
40
0.85 cutoff
1.2
10
Temperature (C)
Avg Annual Precipitation: 500 mm
JJA Mean Temperature: 15.5 C
0.6
1.4
Maximum sample depth for the Barney Lake
chronology is 95 individuals from 4 microsite
locations in the Barney lake cirque area.
12
Precipitation (mm)
200 mi.
0.7
1.6
Barney Lake Rock Glacier Climate Normals, 1971-2000
300
These plants occupy the alpine area above
treeline and other extra-arboreal zones
such as rock glaciers. Their different
growth form indicates that different
environmental and climatological factors
may affect their annual growth increment.
These shrub chronologies are readily
comparable to adjacent tree-ring
chronologies.
80
Correlation with BLRG
Woody shrub stems and taproots have
been used in an increasing number of
climatological and ecological applications:
reconstructing glacial fluctuations in
China, summer temperature and microsite
effects in the Norwegian Alps, and winter
precipitation, AO & NAO phase changes
and nutrient uptake in the Canadian Arctic.
Initial evaluation of climategrowth response. Marker years
in the Barney Lake chronology
indicate extreme growth
responses to drought years (1934,
1961, 1977) and to years with
record snowfall (1983, 1986,
1995) –as indicated in the graph
to the right.
chronology
1. Site Characteristics and Study Description:
15
Actual pNov Ppt.
Reconstructed pNov Ppt.
300
200
100
0
Marker years and Crossdating of Linanthus pungens. Matching
patterns of wide and narrow rings occurring in the same years for sites up
to 65 km distant indicates that regional climate variables control ring width
formation in this species. In particular wide marker years (such as 1934,
1961, 1977 and 1995) occur in years of low precipitation and narrow marker
years (such as 1976, 1983, 1986 and 1991) occur in years of high
snowpack accumulation.
B. Climate Station Chart:
BOLD: indicates long climate data record at high elevation; Temp
and Ppt
Grant Grove
Lodgepole
50 km
Giant Forest
Normal Text: indicates shorter length of record, some variables
missing
Gray Text: indicates much missing data, short period of record,
low elevation
1950
1960
1970
1980
1990
2000
Acknowledgements… I wish to thank Malcolm Hughes, Constance Millar and Robert Westfall for assistance, funding, support,
and encouragement during this study. This research has been funded in part by the Laboratory of Tree-Ring Research, The
University of California White Mountain Research Station, The Geological Society of America and the University of Arizona
College of Science Galileo Circle.
Reference: 2004 Biondi, F. and K. Waikul. DENDROCLIM2002: A C++ program for statistical calibration of climate signals in tree-ring chronologies.
Computers & Geosciences 30: 303-31
2010