SHIH-YU WANG Forest Inventory Analysis (FIA) feasibility in reconstructing climate Department of Plants, Soils, and Climate, and Utah Climate Center, Utah State University, Logan, Utah JOHN D. SHAW Justin DeRose, Simon Wang, John Shaw Forest Inventory and Analysis, Rocky Mountain Research Station, Ogden, Utah (b)"FIA"series"length" Forest Service & Utah State University #"of"years" >50" >100" >150" >200" >250" (Manuscript received 13 August 2012, in final form 5 November 2012) ABSTRACT This study introduces a novel tree-ring dataset, with unparalleled spatial density, for use as a climate proxy. Ancillary Douglas fir and piñon pine tree-ring data collected by the U.S. Forest Service Forest Inventory and Analysis Program (FIA data) were subjected to a series of tests to determine their feasibility as climate proxies. First, temporal coherence between the FIA data and previously published tree-ring chronologies was found to be significant. Second, spatial and temporal coherence between the FIA data and water year precipitation was strong. Third, the FIA data captured the El Niño–Southern Oscillation dipole and revealed considerable latitudinal fluctuation over the past three centuries. Finally, the FIA data confirmed the quadrature-phase coupling between wet/dry cycles and Pacific decadal variability known to exist for the Intermountain West. The results highlight the possibility of further developing high-spatial-resolution climate proxy datasets for the western United States. (The preliminary FIA data are provided online at http://cliserv. jql.usu.edu/FIAdata/ in both station and gridded format.) (c)"FIA"series"count" (a) year" (a) Loca(on of FIA plots with current available tree-­‐ring series (green dots) in the Intermountain West, USA. (b) Loca(on of FIA data used in this study with the period of record in years represented by the size and color of triangles (upper right), overlaid with terrain (shading). (c) Number of valid tree-­‐ring series over (me within Utah. 1. douglas fir pinyon pine Water&year:&Aug,Jul& (c)$Cross!corr:!! Water&year:&Aug,Jul& Correla5on)coefficient) (a))EOF1)FIA:)33.5%) year$ (a) Site map of the FIA pinyon pine (red dot) and Douglas-­‐fir (pink triangle) simon.wang@usu.edu (b)$point-by-point corr: FIA!&!Temp! and chronology development (Fritts 1976). C large spatial grids of chronologies for paleoclim Networks of tree-ring data represent important conFIA!&!Precip! 99%! construction is therefore expensive and time con tributions to the study of regional climate, providing in Geographically uniform reconstructions of temp (a))EOF1)FIA:)33.5%) (b))PC1)FIA) (c))Cross)corr.)w/)PDO) situ evidence of past spatiotemporal climate variability. and precipitation (Fritts 1991) and drought (Co Tree-ring indices yield−)PC1) annually dated records of−)PC1) climate Lag!in!month!of!the!year! −)PDSI) −)PDSI) 2004) have been developed for North America events from specific locations. In the semiarid western99%) longitude/latitude resolution, which is coarse c United States, a voluminous literature has reconstructed FIA!&!Temp! ing the complex climate regimes and terrain past climate using tree-ring chronologies, for example, western United States. While the number 99%! of ch lag$(year)$ precipitation (Gray et al. 2004b), temperature (Briffa gies available from the International Tree-Rin et al. 1992), drought (Cook et al. 2004), and streamflow Bank (ITRDB) for the western United States corr.=0.86) (Woodhouse et al. 2006). substantial, sparse spatial representation rem Classically, the climatically sensitivebtree⬈ Ppreparation oint-­‐by-­‐point cof orrela(on map (contours) etween the FIA dregions, ata and (a) for gridded precipita(on and Because (b) gridded dev many example, Utah. ring chronologies requires careful of species, (b))PC1)FIA) (c))Cross)corr.)w/)PDO) temperature during the wselection ater year (August-­‐July) over the period 1950-­‐1997, overlaid with terrain (shading) and dense spatial networks of classic chronologies ov the FIA s−)PC1) ites (black dreplication, ots). Contours tcross hat are dating, significant at the 99% level are in bold; a 9-­‐point smoothing was sites (e.g., elevation), sample −)PC1) areas is time and cost prohibitive, examination applied. −)PDSI) (c) Cross-­‐correla(on between FIA data, annual precipita(on (solid line) and annual temperature (dashed −)PDSI) sible alternatives should be 99%) line) with a one-­‐month sliding interval from the previous calendar year (-­‐12 for Jan-­‐Dec of considered. last year) through the Here introduce a tree-ring dataset collecte current year (0 for Jan-­‐Dec of this year) to the next year (+12 for Jwe an-­‐Dec of next year). The shaded area indicates Corresponding author address: Shih-Yu (Simon) Wang, Dethe 9 9% s ignificance l evel. partment of Plants, Soils and Climate, and Utah Climate Center, U.S. Forest Service Forest Inventory and A lag$(year)$ Utah State University, 4280 Old Main Hill, Logan, UT 84322-4820. (FIA) Program. The FIA conducts a geogra E-mail: simon.wang@usu.edu; rjderose@fs.fed.us unbiased, systematic sample across the United (b)$FIA$(DF+PP)$and$ITRDB$series$ (a) EOF1 of the gridded FIA data during the period 1800-­‐1995 DOI: 10.1175/JHM-D-12-0124.1 overlaid with the PDSI grids (red dots: Cook and Krusic 2004) and FIA sites (yellow dots). (b) PC1 series (gray blue) overlaid with the four-­‐ (c))Cross)corr.)w/)PDO) ! 2013 American Meteorological Society point average of the PDSI (red) with their correla(on coefficient −)PC1) indicated in the boeom right, both smoothed by a 3-­‐year moving −)PDSI) average. (c) Cross-­‐correla(on of the reconstructed PDO index 99%) (MacDonald and Case 2005) with PC1 (gray blue) and the PDSI (red); e.g., lag -­‐4 means that PC1/PDSI lags PDO by 4 years. The shaded area indicates the 99% significance level ager taking into considera(on the lag$(year)$ reduc(on in degrees of freedom from the moving average. corr.=0.86) Correla5on)coefficient) samples and four ITRDB chronologies (blue cross). (b) Chronology series of ITRDB (blue) and FIA (red) at the ITRDB loca(ons, with the light/thin lines showing raw (b))PC1)FIA) data and thick dashed lines s(a))EOF1)FIA:)33.5%) howing the 9-­‐year moving average. Correla(on coefficients labeled in the lower right were calculated between smoothed (me −)PC1) series. The four ITRDB chronologies are: 1) ut501 – Stockton and Jacoby 1976 −)PDSI) (Douglas-­‐fir); 2) ut527 -­‐ Pederson et al. 2011 (pinyon pine); 3) ut529 – Pederson et al. 2011 (Douglas-­‐fir) and; 4) ut521 – Grow 1998 (pinyon pine). (a)$point-by-point corr:!FIA!&!Precip! Correla5on)coefficient) (a)$FIA$and$ITRDB$sites$ Introduction Reference: DeRose, R. J., S.-Y. Wang, J. D. Shaw, 2013: Feasibility of high-density climate reconstruction based on the Forest Inventory and Analysis (FIA) tree-ring data. Journal of Hydrometeorology, 14, 375–381.