280 likes | 559 Views
Dendroclimatology of Bristlecone Pine ( Pinus longaeva ) during the 20 TH Century. Climate Group “The METH Heads”.
E N D
Dendroclimatology of Bristlecone Pine (Pinuslongaeva) during the 20TH Century
Climate Group “The METH Heads” David J. Bohnert1, Allyson L. Carroll2, Wes Cochran3, Kristen de Graauw1, Christopher R. Dolanc4, S. Michael Edwards5, Sandra Karanitsch-Ackerl6, Chris Konchalski7, Evan Lawley8, Carrie Pucko9, Relena R. Ribbons10, Dorothy Rosene1, Scott Sink11, Jeannine-Marie St Jacques12, Linah Ababneh, and Henri Grissino-Mayer13 1Indiana State University, 2Humboldt State University, 3Louisiana State University, 4University of California—Davis, 5West Georgia University, 6University of Natural Resources and Life Sciences (BOKU), Vienna, 7University of Northern British Columbia, 8The Pennsylvania State University, 9University of Vermont, 10University of Massachusetts, Amherst, 11California Polytechnic State University—San Luis Obispo, 12University of Regina, 13University of Rednecks
Justification • Much of bristlecone pine studies have focused on long chronology, C14 standardization, certain responses to weather (dendrometer) and short-term climate (post -1950) • Salzer et al. (2009) concluded that high elevation bristlecone pines were responding to temperature in their growth during the last half of the 20th Century • Literature review did not find any thorough low-elevation 20th century climate analyses • The “Meth” heads hope to understand how bristlecone pine at low-elevation treeline in the White Mountains reacts to climate during the 20th Century
Objectives • Create a crossdated chronology from Methuselah Ridge • Assess climate sensitivity of bristlecone pine growth to climate factors that include temperature, precipitation , streamflow, moisture availability, as well as oceanic-atmospheric oscillations • Determine if these climate-growth relationships are stable over the 20th century
Site Description • Inyo National Forest • Methuselah Ridge • Lower elevation site • 2,910 m to 3,000 m elev. • 37.380 N; 118.165 W • 30 ˚ slope facing NNE • Light colored dolomite substrate
Sample Preparation Like boom! • Selected 33 cores from a previous collection (21 trees) • Sanded with progressively finer grit sandpaper • Up to 400 grit using a belt sander • Finishing with 30 µm and 9 µm hand sanding
Crossdating Like boom! • Used List Method (Yamaguchi, 1991) • Marker rings from the Methuselah Walk chronology extracted from the ITRDB
Constructing a Master Chronology • Measured ring widths using Velmex system and Measure J2X • COFECHA used for quality control of crossdating • ARSTAN used for developing chronologies • Linear detrending applied
Compiling Climate Data • PRISM • NOAA Divisional • Local stations: Bishop, Independence, Mina (NV) • Streamflow • PDO • SOI • NAFO Jeannine – The Climate Queen
Climate Analyses • DendroClim2002 • Standard, Residual, ARSTAN chronologies • Correlation analyses conducted with a moving 35 year window • Statistical significance evaluated using bootstrapping techniques • Wavelet analysis to visualize low-frequency trends
Chronologies StandardResidualARSTAN
Maximum Temperature PRISM Bishop, CA
Precipitation vs Residual Chronology CA Division 7 PRISM CA Division 07 SPI Independence, CA
Possible Phase Shift PDSI CA 07 – Standard Chronology PDO – Standard Chronology
Comparison of PDO indices and the Methuselah Walk Standard Chronology Discussion
Bristlecone pine growth throughout the 20th century correlates best with precipitation Precipitation/tree growth relationship stable over time Streamflow correlates very well with growth, particularly in late spring Temperature correlates negatively with growth – tied to precip. effects PRISM May Temp Discussion
Other studies have observed similar trends with precip and temp (LaMarche 1974; Salzer et al. 2009) No other studies have documented Bristlecone growth trends with streamflow and PDO Discussion
“… a single record of average ring width in the upper tree line environment provides a guide to past temperature fluctuations. However, comparison of this record with another, that of the arid lower forest border, from the same area permits characterization of associated precipitation and temperature anomalies that may, in turn, be linked to features of the general circulation. Other approaches that promise to be very fruitful include study of the variation of ring-width statistics through time, …” –LaMarche 1974
Acknowledgements • Blanco Mountain Café • Sumo, Shadow, Tim • Dr. James H. Speer • NADEF • Crooked Creek White Mountain Research Station • NSF • Mammoth Brewing Co.