DOI: 10.25921/fe2g-xv19
title: NOAA/WDS Paleoclimatology - Higuera fire data from Uchugrak Lake, Noatak River Valley, Northwestern Alaska - IMPD USUC-001

description: Tundra fires have important ecological impacts permafrost, and carbon cycling, but the on vegetation, wildlife, pattern and controls of historic tundra fire regimes are fire and vegetation history poorly understood. We use sediment records from four lakes to in a highly flammable tundra region develop a 2000-yr and compare this history with previously published fire records to examine spatial across Arctic Alaska. The four sites span and temporal variability a modern climatic gradient of tundra burning in the Noatak National Preserve, from warmer, drier down-valley locations. Modern vegetation valley sites, and pollen data past two millennia. Peaks in event return intervals (FRIs), locations to cooler, generally moister up-valley varies from herb- to shrub-dominated tundra from down- to up- suggest that this spatial pattern in macroscopic charcoal accumulation which did not vary significantly vegetation persisted over the provide estimates of fire- at millennial time scales but did vary across space. Down-valley with median FRIs of 150 years (95% sites burned relatively frequently CI 101-150) over the past similar to those from ancient shrub tundra and modern boreal forest. At significantly longer than those at 128-285). These differences evaporative demand at shaped tundra fire two millennia, and FRI distributions statistically up-valley sites FRIs were down-valley sites, with a median FRI of 218 likely reflect the cooler up-valley sites, but local-scale regimes. Comparisons with other that the tundra biome can sustain a wide range years (95% CI growing-season temperatures and lower variability in vegetation may have also long-term fire records in Alaska reveal of burning, with individual FRIs from as low as 30 years to more than 5000 burning has occurred under a years. These records range of climatic and fire histories within Alaska suggests together indicate that vegetation scenarios. The that the ecological impacts frequent tundra variety of tundra of tundra burning likewise vary widely, for wildlife-habitat maintenance and for the responses with important implications of tundra biophysical and biogeochemical processes Key words: Alaska; Arctic; charcoal analysis; climatic to climatic change.
description: Higuera charcoal, pollen, and chronology data from Uchugrak Lake, Noatak River Valley, Northwestern Alaska

Uchugrak Lake data file contents: 
(1.) usuc-001.txt contains: (a.) metadata, (b.) charcoal data in the "Data" section (which are the same as data the charcoal data in usuc-001-uc07-char-data.csv [CharAnalysis input file, see below for more details]), and (c.) a "Chronology" section which includes depth and age data from the published age-depth model. Online Resource: http://www.ncei.noaa.gov/pub/data/paleo/firehistory/charcoal/northamerica/usuc-001.txt

(2.) usuc-001-uc07-char-data.csv Charcoal data which is the raw input to CharAnalysis. See https://sites.google.com/site/charanalysis/  and "Supplement Information" section below for more details. Note: the data in this file are the same as the data in the "Data" section of: http://www.ncei.noaa.gov/pub/data/paleo/firehistory/charcoal/northamerica/usuc-001.txt. Online_Resource: http://www.ncei.noaa.gov/pub/data/paleo/firehistory/charcoal/northamerica/supplemental/usuc-001-uc07-char-data.csv, 

(3.) usuc-001-uc07-char-params.csv CharAnalysis parameter file. See https://sites.google.com/site/charanalysis/ for description of parameters file, and "Supplement Information" section below for more details. Online_Resource: http://www.ncei.noaa.gov/pub/data/paleo/firehistory/charcoal/northamerica/supplemental/usuc-001-uc07-char-params.csv, 

(4.) usuc-001-uc07-char-results.csv CharAnalysis results file. Units are in the column headers: See https://sites.google.com/site/charanalysis/ , and "Supplement Information" section below for more details. Online_Resource: http://www.ncei.noaa.gov/pub/data/paleo/firehistory/charcoal/northamerica/supplemental/usuc-001-uc07-char-results.csv,  

(5.) usuc-001-uc07-pollen-counts.xls  Pollen counts for each sample. Online_Resource: http://www.ncei.noaa.gov/pub/data/paleo/firehistory/charcoal/northamerica/supplemental/usuc-001-uc07-pollen.xls

(6.) higuera2011-ak-tundrafirehx-lakesedrecords_2008.kmz - Supplement - *Google Earth files (.kmz) with location of lakes used and referenced in this study (see Fig. 1 in main text), and polygons of recorded fires in Alaska from 1950 to 2007. /Ecological Archives/ A021-144-S1*. Location of high-resolution lake-sediment records reporting fire history information from Alaskan tundra, over the mid and late Holocene (DI, PE, RA, UC, PO, LI) and late Glacial and early Holocene (RP, XI). Records from the late Holocene representing boreal forest (RP, XI, CO, WK) are also included, because these are compared to tundra fire history records. Metadata include lake name, site code, year cored, surface area (ha), water depth (m), and publication information.

(7.) higuera2011-ak-tundrafires-cavm-2010.kmz - Supplement - *Google Earth files (.kmz) with location of lakes used and referenced in this study (see Fig. 1 in main text), and polygons of recorded fires in Alaska from 1950 to 2007. /Ecological Archives/ A021-144-S1*. Polygons of tundra area burned in Alaska from 1950 to 2010, as reported by the Alaska Interagency Coordination Center (http://fire.ak.blm.gov/predsvcs/maps.php). 'Tundra' is defined as all areas within the Circumpolar Arctic Vegetation Map (CAVM, Walker et al. 2005) in Alaska. LITERATURE CITED Walker, D. A., M. K. Raynolds, F. J. A. Daniels, E. Einarsson, A. Evlvebakk, W. A. Could, A. E. Katenin, S. S. Kholod, C. J. Markon, E. S. Melnikov, N. G. Moskalenko, S. S. Talbot, and B. A. Yurtsev. 2005. The circumpolar Arctic vegetation map. Journal of Vegetation Science 16:267 282.'


Supplement Information 
    from Ecological Archives A021-144-S3:
Raw and analyzed charcoal data for the past 3000 years for Raven(Site Code: RA, IMPD Code: usra-001), Uchugrak(Site Code: UC, IMPD Code: usuc-001), Poktovik(Site Code: PO, IMPD Code: uspo-001), and Little Isac lakes(Site Code: LI, IMPD Code: usli-001). /NOTE/: analysis results are based on analyzing the entire charcoal record at each site. Results near start of record may differ when shorter records are analyzed. /Ecological Archives/ A021-144-S3

Supplemet Authors:
 Philip E. Higuera, College of Natural Resources, Box 441133, University of Idaho, Moscow, ID 83844-1133, USA, E-mail: phiguera@uidaho.edu <mailto:phiguera@uidaho.edu>
 Melissa L. Chipman, Department of Plant Biology, University of Illinois, 505 South Goodwin Avenue, Urbana, IL 61801, USA
 Jennifer L. Barnes, National Park Service, 4175 Geist Road, Fairbanks, AK 997009, USA, Michael A. Urban, Department of Plant Biology, University of Illinois, 505 South Goodwin Avenue, Urbana, IL 61801, USA
 Michael A. Urban, Department of Plant Biology, University of Illinois, 505 South Goodwin Avenue, Urbana, IL 61801, USA

Supplement Files:
usra-001-ra07-char-data.csv
usra-001-ra07-char-params.csv
usra-001-ra07-char-results.csv
usuc-001-uc07-char-data.csv
usuc-001-uc07-char-params.csv
usuc-001-uc07-char-results.csv
uspo-001-po07-char-data.csv
uspo-001-po07-char-params.csv
uspo-001-po07-char-results.csv
usli-001-li07-char-data.csv
usli-001-li07-char-params.csv
usli-001-li07-char-results.csv

Description of Supplement Files

For each site, three files provide the raw input data, the parameters used, and the output data for charcoal analysis via the program CharAnalysis (see 'Methods' in main text). File names reference site codes: li (Little Isac), po (Poktovik), ra (Raven), and uc (Uchugrak). The '*-char-results.csv' files has data on fire return intervals and smoothed fire frequency removed, given that these calculations were done outside of the program and do not reflect the time intervals given in the *-char-params.csv files.

Missing values denoted by -9999 (*-char-params.csv) or NaN(*-char-results.csv).

    **07-char-data.csv includes the following *raw* data (by column):

        cmTop: top depth (cm) of the sample
        cmBot: bottom depth (cm) of the sample
        ageTop: estimated age at top of sample (cal. yr before CE 1950)
        ageBot: estimated age at bottom of sample (cal. yr before CE 1950)
        charVol: volume of sediment subsample from which charcoal was
        prepared (cm^3 )
        charCount: pieces of charcoal counted in the sample (#)

        Checksum values:

            usli-001-li07-char-data.csv: 192 rows (with headers), 6 columns

                Column 3 (ageTop (yr BP)): 313963
                Column 6 (charCount (#)):1586 

            uspo-001-po07_char-data.csv: 234 rows (with headers), 6 columns

                Column 3 (ageTop (yr BP)): 438415
                Column 6 (charCount (#)): 823 

            usra-001-ra07-char-data.csv: 302 rows (with headers), 6 columns

                Column 3 (ageTop (yr BP)): 448677
                Column 6 (charCount (#)): 556 

            usuc-001-uc07_char-data.csv: 393 rows (with headers), 6 columns

                Column 3 (ageTop (yr BP)): 534182
                Column 6 (charCount (#)): 543 

    **07_char-params.csv:

        See CharAnalysis User's Guide for description of parameters
        file, available at https://sites.google.com/site/charanalysis/

        Checksum values:

            usli-001-li07-char-params.csv: 26 rows (with headers), 5 columns

                Column 3 (Parameters): -49519.821 

            uspo-001-po07-char-params.csv: 26 rows (with headers), 5 columns

                Column 3 (Parameters): -52975.821 

            usra-001-ra07-char-params.csv: 26 rows (with headers), 5 columns

                Column 3 (Parameters): -5199.821 

            usuc-001-uc07-char-params.csv: 26 rows (with headers), 5 columns

                Column 3 (Parameters): -51479.821 

    **07_char-results.csv includes the following *derived* data
    (reflecting interpolation)

        cmTop_i: top depth (cm) of interpolated sample
        ageTop_i: bottom depth (cm) of interpolated sample
        charCount_i: pieces of charcoal in interpolated sample
        charVol_i: volume of interpolated sample
        charCon_i: charcoal concentration in interpolated sample
        (pieces/cm^3 )
        charAcc_i: charcoal accumulation rate, based in interpolated
        concentration and age (pieces/cm^2 *yr)
        charBkg: background charcoal, C_back , smoothed based on methods
        selected in *_charParams.csv file, (pieces/cm^2 *yr)
        charPeak: peak charcoal, C_peak , based on methods selected in
        *-char-params.csv file, (pieces/cm^2 *yr)
        thresh1: threshold value (pieces/cm^2 *yr) based on first
        threshold entered in *-char-params.csv file
        thresh2: same as thresh1, but for second threshold entered
        thresh3: same as thresh1, but for third threshold entered
        threshFinalPos: positive threshold value (pieces/cm^2 *yr),
        based on fourth threshold value entered in *charParams.csv file.
        threshFinalNeg: negative threshold value (pieces/cm^2 *yr),
        based on fourth threshold value entered in *charParams.csv file.
        SNI: signal-to-noise index values, based on threshdFinalPos values.
        threshGOF: /P/ value from KS goodness-of-fit test between fitted
        noise distribution and empirical data below the sample-specific
        threshold.
        peaks1: samples that exceed thresh1 values are identified by
         1 . Only the first sample is identified.
        peaks2: same as peaks1, but for the second threshold value
        peaks3: same as peaks1, but for the third threshold value
        peaksFinal: same as peaks1, but for the final threshold value
        peaksInsig.: peaks that exceeded threshFinalPos (the final
        threshold), but did not pass the minimum-count test are
        identified with a  1 
        peakMag: peak magnitude is the total pieces of charcoal
        accumulated in a given peak (pieces/cm^2 *peak). If a peak is
        only one sample long, then peak magnitude is simply CHAR minus
        the positive threshold. If a peak is more than one sample long,
        then each sample exceeding threshFinal is summed.

        Checksum values:

            usli-001-li07-char-results.csv: 206 rows (with headers), 21 columns

                Column 2 (age Top_i): 301965
                Column 6 (char Acc_i): 9.139
                Column 19 (peaks Final): 14 

            uspo-001-po07-char-results.csv: 206 rows (with headers), 21 columns

                Column 2 (age Top_i): 301965
                Column 6 (char Acc_i): 4.5649
                Column 19 (peaks Final): 12 

            usra-001-ra07-char-results.csv: 206 rows (with headers), 21 columns

                Column 2 (age Top_i): 301965
                Column 6 (char Acc_i): 3.1762
                Column 19 (peaks Final): 17 

            usuc-001-uc07-char-results.csv: 206 rows (with headers), 21 columns

                Column 2 (age Top_i): 301965
                Column 6 (char Acc_i): 3.655
                Column 19 (peaks Final): 24 

 --- End of Supplement section --;

Keywords, Alaska, Arctic, charcoal analysis, climatic change, environmental change, fire history, fire management, historical range of variability, Noatak National Preserve, pollen analysis, shrub tundra, tundra; 

Site size (ha), 3.7; 

Contact person, Philip Higuera, phiguera@uidaho.edu, pehiguera@gmail.com; 

Water depth (cm), 920;