Philip E. Higuera, Melissa L. Chipman, Jennifer L. Barnes, Michael A. Urban, and Feng Sheng Hu. 2011. Variability of tundra fire regimes in Arctic Alaska: millennial-scale patterns and ecological implications. Ecological Applications 21:3211–3226.


Supplement

Raw and analyzed charcoal data for the past 3000 years for Raven, Uchugrak, Poktovik, and Little Isac lakes. 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
.

Copyright


Authors
File list (downloads)
Description


Author(s)

Philip E. Higuera
College of Natural Resources
Box 441133
University of Idaho
Moscow, ID 83844-1133
USA
E-mail: 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


File list

LI07_charData.csv
LI07_charParams.csv
LI07_charResults.csv
PO07_charData.csv
PO07_charParams.csv
PO07_charResults.csv
RA07_charData.csv
RA07_charParams.csv
RA07_charResults.csv
UC07_charData.csv
UC07_charParams.csv
UC07_charResults.csv

Description

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 “*_charResults.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 *_charParams.csv files.

Missing values denoted by -9999 (*_charParams.csv) or NaN (*_charResults.csv).

**07_charData.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 (cm3)
charCount: pieces of charcoal counted in the sample (#)

Checksum values:

LI07_charData.csv: 192 rows (with headers), 6 columns
Column 3 (ageTop (yr BP)): 313963
Column 6 (charCount (#)):1586
PO07_charData.csv: 234 rows (with headers), 6 columns
Column 3 (ageTop (yr BP)): 438415
Column 6 (charCount (#)): 823
RA07_charData.csv: 302 rows (with headers), 6 columns
Column 3 (ageTop (yr BP)): 448677
Column 6 (charCount (#)): 556
UC07_charData.csv: 393 rows (with headers), 6 columns
Column 3 (ageTop (yr BP)): 534182
Column 6 (charCount (#)): 543

**07_charParams.csv:

See CharAnalysis User’s Guide for description of parameters file, available at the web site linked to above.

Checksum values:

LI07_charParams.csv: 26 rows (with headers), 5 columns
Column 3 (Parameters): -49519.821
PO07_ charParams.csv: 26 rows (with headers), 5 columns
Column 3 (Parameters): -52975.821
RA07_ charParams.csv: 26 rows (with headers), 5 columns
Column 3 (Parameters): -5199.821
UC07_ charParams.csv: 26 rows (with headers), 5 columns
Column 3 (Parameters): -51479.821
**07_charResults.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/cm3)
charAcc_i: charcoal accumulation rate, based in interpolated concentration and age (pieces/cm2*yr)
charBkg: background charcoal, Cback, smoothed based on methods selected in *_charParams.csv file, (pieces/cm2*yr)
charPeak: peak charcoal, Cpeak, based on methods selected in *_charParams.csv file, (pieces/cm2*yr)
thresh1: threshold value (pieces/cm2*yr) based on first threshold entered in *_charParams.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/cm2*yr), based on fourth threshold value entered in *charParams.csv file.
threshFinalNeg: negative threshold value (pieces/cm2*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/cm2*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:

LI07_charResults.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
PO07_charResults.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
RA07_charResults.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
UC07_charResults.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