Above-treeline Linanthus pungens shrub-chronologies on the eastern Sierra crest, Mono Co., contain records of precipitation and temperature Rebecca Franklin, Laboratory of Tree-Ring Research, University of , Tucson, AZ, USA

1. Site Characteristics and Study Description: 4. Barney Lake Chronology Description 6. Climate-Growth Response

10 mi. Initial evaluation of climate- Barney Lake Linanthus pungens A. BLRG Residual EPS, SSS value, .85 cut-off and sample depth growth response. Marker years 1 100 1.4 N chronology in the Barney Lake chronology 0.9 0.8 80 indicate extreme growth Here I present the first shrub-ring chronology 0.7 responses to drought years (1934, 1.2 1934: drought for L. pungens in North America. In panel B is 0.6 60 1961, 1977) and to years with 0.5 the L. pungens residual index values in black BLRG res SSS record snowfall (1983, 1986, 0.4 40 with the +/- 1 SD levels shaded in gray. EPS 0.85 cutoff 1995) –as indicated in the graph 1 0.3 Woody shrub stems and taproots have values for the Barney Lake site chronology BLRG res EPS to the right. 0.2 20 been used in an increasing number of reach 0.85 (for a sample depth of 16) only after BLRG sample depth 0.1 0.8 climatological and ecological applications: 1952 so I truncate the chronology there and Wide annual rings occur during reconstructing glacial fluctuations in 2 0 use only 1952-2007 index values in my 1940 1950 1960 1970 1980 1990 2000 drought years. L. pungens China, summer temperature and microsite 1.8 effects in the Norwegian Alps, and winter correlations and response functions. inhabits dry cool (north-facing) 0.6 precipitation, AO & NAO phase changes Barney Lake Rock Glacier Climate Normals, 1971-2000 1.6 rocky sites and is not limited (as and nutrient uptake in the Canadian Arctic. Maximum sample depth for the Barney Lake 1.4 indicated by this study) by 300 14 1983 & 1986: heavy snowfall 1.2 0.4 These occupy the alpine area above chronology is 95 individuals from 4 microsite moisture. Narrow rings occur 12 1 treeline and other extra-arboreal zones locations in the Barney lake cirque area. accompanying record snow pack 1930 1940 1950 1960 1970 1980 1990 2000 2010 250 such as rock glaciers. Their different 10 0.8 and cool growing season growth form indicates that different 8 Subsample signal strength, EPS values and 0.6 temperatures. This could be as a environmental and climatological factors 200 sample depth are presented in panel A. 0.4 result of the mechanics of being 200 mi. may affect their annual growth increment. 6 covered by snow pack and unable to photosynthesize or from cool growing season temperatures. 0.2 B. Barney Lake Rock Glacier Residual Index +/- 1 SD These shrub chronologies are readily 150 4 comparable to adjacent tree-ring 0 2 chronologies. 1930 1940 1950 1960 1970 1980 1990 2000 2010 100 0 Temperature (C) Avg Annual Precipitation: 500 mm (mm) Precipitation To study recent (past 100 years) climate A. Ranked April SWE correlations with Barney Lake Chronology B. Snowpack and Drought: correlations with BL Chronology -2 0.6 JJA Mean Temperature: 15.5 C and ecological change in the alpine Eastern 50 Barney Lake Rock Glacier Non-Rock Variable BLRG chronology Correlation df p-value Sierra Nevada I utilize the ring width -4 Glacier site 0.4 p < .05 p < .05 ~37.5N lat., 119W long. patterns archived in the taproots of woody 0 -6 By Aspect 0.2 PDSI shrubs growing above treeline. BLRG Chronology Residual Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec BLRG Site -0.29 50 < 0.05 0 Chronology 90 60 20 Level ground 230 Statistics. Standardized -0.23 50 < 0.10

chronology Ring Width -0.35 50 < 0.02 Raw Ring Widths -0.2

Site statistics are listed for with BLRG Correlation -0.4 Chronology length 1895-2007 1931-2007 1934-2007 1928-2007 1930-2007 1895-2007 SWE Number of Years 112 76 73 79 77 112 microsite chronologies -0.6 Residual -0.25 54 < 0.10 Year EPS > 0.85 1954 1948 1986 1962 1963 1959 sorted by aspect (90 deg., Standardized -0.25 54 < 0.10 2. Barney Lake Rock Glacier Botany and Wood Anatomy 60 deg., 20 deg., no aspect, -0.8 Ring Width -0.18 54 < 0.20 Average sample length 49 49 43 46 45 71 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 and 230 deg.) and are also Sample size (# plants) 95 39 22 27 19 9 April SWE relative value (deciles) 1927 - 2007 Average sorted by full site Family Species Maximum Age Mean Ring Width (mm) 0.093 0.087 0.101 0.093 0.087 0.108 Asteraceae Antennaria rosea chronology vs. non-rock Drought and snowpack variability as controls on Barney Lake L. pungens chronologies. Standard Deviation 0.18 0.15 0.16 0.17 0.29 0.26 Asteraceae Circium scaciosum glacier paired site and raw Initial correlations with a drought metric (Palmer Drought Severity Index, PDSI) and snowpack metric (April Snow Water Asteraceae Ericameria discoidea 70 years ring widths vs. standardized Equivalent) were significant but did not prove to be stable predictors of growth over time. Standardized Chronology Asteraceae Ericameria suffruticosa 70 years chronology. Mean 0.979 0.992 0.985 0.973 0.9853 0.992 To account for this relationship between shrub ring growth and snowpack I sorted years of April SWE (Tioga Pass) into deciles Asteraceae Erigeron pygmaus Standard deviation 0.138 0.148 0.163 0.167 0.2529 0.256 and regressed each of the ten deciles against ring width growth for the same years (Figure A). Both the highest deciles for SWE Asteraceae Erigeron compositus Signal to Noise Ratio 7.049 6.642 2.862 2.361 2.111 4.685 and the lowest decile for SWE were highly (r= .9 - .8) negatively correlated with ring width growth for those years (p < 0.05). Asteraceae Solidago multiradiata 14 years RBAR 0.234 0.315 0.156 0.239 0.258 0.539 Brassicaceae Arabis lemmonnii Mean Sensitivity 0.160 0.140 0.152 0.140 0.2048 0.202 Brassicaceae Erysimum capitatum var. perenne 10 years Caryophyllaceae Arenaria kingii Auto-correlation 0.296 0.221 0.283 0.398 0.4848 0.561 Caryophyllaceae Silene sargentia Correlation and Response Functions: PDO, PRISM Tmax, Tmin & Precipitation values Grossulariaceae Ribes cereum 100+ years Correlations generated for the Hydrophyllaceae Phacelia hastata ssp. compacta Thin section images of the five most common woody shrubs at BLRG site. Scale is 1 mm. Comparison of raw ring width PDO correlations significant at 95% confidence level T min correlations significant at 95% confidence level Barney Lake chronology using Lamiaceae Monardella odoratissima 45 years a) Ericameria discolor, b) Linanthus pungens, c) Monardella odoritissima, d) diffusa, e) Salix chronologies for 4 aspects at the DendroClim2002 were Onagraceae Castilleja nana spp. These species are long lived and due to completely lignified taproots have potential for high Barney Lake site. A) 90 degrees, b) 60 significant only for previous Onagraceae Castilleja appellgatia elevation dendrochronological studies. Linanthus pungens, is particularly long-lived, does not degrees, c) 25 degrees, d) level ground/no winter’s precipitation (Oct-Jan) Linanthus pungens 120 years x suffer from root-rot and has exceptionally clearly demarcated growth rings. aspect and e) 270 degrees. Chronologies and the current growing Polemoniaceae Phlox diffusa 40 years a through d are located on the Barney season’s (June/July) Polygonaceae Eriogonum ovalafolium Rock Glacier and site e is on the Barney temperature, Tmax and Tmin. Polygonaceae Eriogonum incanum A Lake non-rock glacier paired site. Response functions significant Primulaceae Primula suffretescens B C at the 95% confidence level Pteridaceae Athyrium alpestre For all raw ring width chronologies there is were only found for July Pteridaceae Pellaea brewerii an increasing trend in ring width I the latter temperatue (Tmin and Tmax) Ranunculaceae Aquilegia pubescens 25 years half of the 20th century. This is likely due to Rosaceae Holodiscus microphyllus the occurrence of younger individuals later Temperature and precipitation Salicaceae Salix spp values were taken from the in the chronology as the trend is not seen Precip correlations significant at 95% confidence level Tmax correlations significant at 95% confidence level Selaginellaceae Selaginella watsonii in the standardized chronology PRISM data set for latitude 37.56491N and longitude Photo: C. Millar, 2007 Photo: C. Millar, 2007 Species composition of BLRG. I catalogued 27 118.9701 W. species growing on the rock glacier. Nine of the x species in particular had long-lived persistent Distinct rock glacier microsites. BLRG has many discrete patches of Temperature and precipitation taproots with annual growth bands contained surface that support distinct species compositions. A) woody shrubs values for all weather stations Photo: C. Millar, 2007 therein. Ericameria spp, B) Phlox diffusa, C) Primula suffretescens 5. Climate Station and Data Issues x in the Sierra Nevada range were not significantly 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 correlated with the Barney yet virtually all have incomplete records and missing data that makes them unsuitable for use in climate reconstruction and temperature monitoring Lake chronology in rapidly changing, climatically sensitive areas. In the figures below I show the distribution of climate stations and the lack of complete records for 3. Linanthus pungens: species selection, and cross-dating this area. This underscores the importance of above-treeline studies such as this one for the study of alpine ecosystems

A. Climate Station Map B. Climate Station Chart 1961: Drought 1976 Record 1983 +1986: 1990, 1991: A. Stability of Climate relationships over time cold summer record snowpack Drought Climate Station Elevation Temp Snow Ppt 1977: drought 1995: rcrd BODIE 2551 1964-2010 1964-2010 1964-2010 April SWE PDSI pNov Ppt July avg T snowpack N LUNDY LAKE 2367 1931-1940 1931-1940 1931-1940 Period Correl df p Correl df p correl df p Correl df p Bodie MONO LAKE/LEE VINING 2000 1950-2010 1950-2010 1950-2010 ELLERY LAKE 2940 1931-1949 1931-1965, 1982-2010 1931-2010 1952-1979 -0.0493 26 -- -0.0290 26 -- -0.2964 26 < 0.05 0.4164 26 < 0.025 GEM LAKE 2734 1931-1950 1931-1950, 1981-2010 1931-2010 (no 51-54) Lundy Lake YOSEMITE PARK HQ 1225 1931-2010 1931-2010 1931-2010 1980-2007 -0.5460 26 < 0.005 -0.5070 23 < 0.025 -0.3675 26 < 0.05 0.3676 26 < 0.05 Mono Lake MAMMOTH LAKES RS 2379 1993-2010 1994-2010 1994-2010 Ellery Lake Lee Vining YOSEMITE SOUTH ENTR. 1538 1941-2010 1941-2010 1941-2010 B. “Reconstructions” LAKE SABRINA 2763 1931-1949 1931-1948, 1988-2010 1931-1948, 1988-2010 Stability of Climate-growth Relationships over Time. 25 BIG CREEK PH 1 1487 1931-1962, 1999-2010 1931-1962, 1999-2010 1931-1962, 1999-2010 Yosemite Park HQ To test the stability of potential regression models, the Gem Lake ASPENDELL 2591 1931-1941, 2002-2010 1931-1941, 2002-2010 1931-1941, 2002-2010 chronology was divided into calibration and verification 23 BISHOP CREEK INTAKE 2485 - 1982-2010 1959-2010 periods: 1952-1979 and 1980-2007. Mammoth Lakes RS HUNTINGTON LAKE 2140 1931-2010 1931-2010 1931-1962, 1974-2010 21

SOUTH LAKE 2920 1931-1948 1931-1948, 1988-2010 1931-1948, 1975-2010 Both April SWE and PDSI correlations with the Barney Lake 19 Yosemite South Entr GRANT GROVE 2012 1940-2010 1940-2010 1940-2010 chronology were not stable over the full chronology length. LODGEPOLE 2053 1968-2010 1951-1955, 1968-2010 1951-1955, 1968-2010 17 Actual Avg July T Avg July Temperature (C) Temperature July Avg Linanthus pungens (Torr.) Torr. ex Nutt. Commonly known as Granite Gilia or Reconstructed Avg July T GIANT FOREST 1955 1931-1968 1931-1968 1931-1968 Correlations with both the previous year’s November Prickly Phlox, this species is in the Polemoniaceae family. It can achieve ages of 15 precipitation and the current growing year’s July temperature Actual pNov Ppt. 120 years at high elevations in the mountainous west. It’s distribution is A. Climate Station Map: (Tmax and Tmin) were stable over time. However, even Reconstructed pNov Ppt. throughout the western United States and into southwest Canada. 300 Huntington Lake Aspendell GREEN TEXT: though the correlations are significant, the R2 values are low It occupies dry rocky and sandy sites from 1000 – 3500 m.a.s.l. Its leaves are Bishop Creek Intake Low elevation Temperature and Precipitation data available for full record as can be seen in panel B to the right. Lake Sabrina alternate palmately lobed, 5-9 lobes and spiny-tipped. Big Creek PH 200 South Lake RED TEXT: High elevation Temperature and Precipitation data available for full record The value of the “reconstructions” is limited, obviously, by the Circuit Uniformity and ring 100 0.9 width measurement in L. (Black text indicates missing data, short period of record) fact that the chronology length does not extend further back in pungens. Sub-shrubs used in time than the actual PRISM climate variables. (mm) Precipitation pNovember 0.8 dendrochronological applications 0 1950 1960 1970 1980 1990 2000 2010 0.7 usually have poorer circuit B. Climate Station Chart: uniformity that tree species. How BOLD: indicates long climate data record at high elevation; Temp

BAI 0.6 many radii are necessary to Marker years and Crossdating of Linanthus pungens. Matching and Ppt measure to accurately Grant Grove Acknowledgements… I wish to thank Malcolm Hughes, Constance Millar and Robert Westfall for assistance, funding, support, 0.5 patterns of wide and narrow rings occurring in the same years for sites up approximate annual growth Normal Text: indicates shorter length of record, some variables and encouragement during this study. This research has been funded in part by the Laboratory of Tree-Ring Research, The increment? For a sample size of to 65 km distant indicates that regional climate variables control ring width 0.4 missing University of California White Mountain Research Station, The Geological Society of America and the University of Arizona 11 individuals I found that taking formation in this species. In particular wide marker years (such as 1934, Lodgepole College of Science Galileo Circle. 0.3 more than three radii did not Average Correlation between RW and and RW between Correlation Average 0 1 2 3 4 5 6 7 1961, 1977 and 1995) occur in years of low precipitation and narrow marker Gray Text: indicates much missing data, short period of record, increase accuracy of annual 50 km Giant Forest Reference: 2004 Biondi, F. and K. Waikul. DENDROCLIM2002: A C++ program for statistical calibration of climate signals in tree-ring chronologies. Number of Radii included in Ring Width Measurement growth increment measurement. years (such as 1976, 1983, 1986 and 1991) occur in years of high low elevation Computers & Geosciences 30: 303-31 snowpack accumulation.