DOI: 10.25921/pef0-zz47
title: NOAA/WDS Paleoclimatology - North American Tree-ring Fire Scar Synthesis (NAFSS)

description: Fire regimes in North American forests are diverse and modern fire records are often too short to capture important patterns, trends, feedbacks, and drivers of variability. Tree-ring fire scars provide valuable perspectives on fire regimes, including centuries-long records of fire year, season, frequency, severity, and size. Here, we introduce the newly compiled North American tree-ring fire-scar network (NAFSN), which contains 2562 sites, >37,000 fire-scarred trees, and covers large parts of North America. We investigate the NAFSN in terms of geography, sample depth, vegetation, topography, climate, and human land use. Fire scars are found in most ecoregions, from boreal forests in northern Alaska and Canada to subtropical forests in southern Florida and Mexico. The network includes 91 tree species, but is dominated by gymnosperms in the genus Pinus. Fire scars are found from sea level to >4000-m elevation and across a range of topographic settings that vary by ecoregion. Multiple regions are densely sampled (e.g., >1000 fire-scarred trees), enabling new spatial analyses such as reconstructions of area burned. To demonstrate the potential of the network, we compared the climate space of the NAFSN to those of modern fires and forests; the NAFSN spans a climate space largely representative of the forested areas in North America, with notable gaps in warmer tropical climates. Modern fires are burning in similar climate spaces as historical fires, but disproportionately in warmer regions compared to the historical record, possibly related to under-sampling of warm subtropical forests or supporting observations of changing fire regimes. The historical influence of Indigenous and non-Indigenous human land use on fire regimes varies in space and time. A 20th century fire deficit associated with human activities is evident in many regions, yet fire regimes characterized by frequent surface fires are still active in some areas (e.g., Mexico and the southeastern United States). These analyses provide a foundation and framework for future studies using the hundreds of thousands of annually- to sub-annually-resolved tree-ring records of fire spanning centuries, which will further advance our understanding of the interactions among fire, climate, topography, vegetation, and humans across North America.
description: Fire regimes in North American forests are diverse and modern fire records are often too short to capture important patterns, trends, feedbacks, and drivers of variability. Tree-ring fire scars provide valuable perspectives on fire regimes, including centuries-long records of fire year, season, frequency, severity, and size. The goal of this project is to make all fire scar sites in North America publicly available.

The complete list of data contributors to date follows:  
Margolis, E.Q.; Guiterman, C.H.; Huffman, D.W.; Kaib, M.J.; O'Connor, C.D; Stan, A.

All fire scar site FHX data, metadata and supplemental files of this study, along with all other IMPD North America fire scar files, are located in folder (URL):
https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/
The folder's sub-folder fire-hist-graphs contains fire history graphs for all sites of this study, and its supplemental sub-folder contains supplemental data files such as supplemental (tree) data.

Please visit the following S1 file for an up to date list of metadata for all fire scar data sites:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/s1-NAFSS.csv
  A description for each column of this file follows:
    A. site_name - name of the fire scar site
    B. impd_code - International Multi-proxy Paleofire Database(IMPD) code, 
           assigned by NOAA
    C. Investigators - investigators
    D. first_year - earliest year contained in the FHX data file, AD units
    E. last_year - most recent year in the FHX file, AD units
    F. latitude - latitude in decimal degrees
    G. longitude - latitude in decimal degrees
    H. elevation - elevation in meters
    I. species - species codes; a full description of each species code is 
       available from URL: 
       https://www.ncei.noaa.gov/pub/data/paleo/templates/tree-species-code.csv 
    J. number_of_trees - count of trees in the sites FHX data file
    K. reference_1 - top-ranked publication, any others are listed in the 
       sites metadata file, listed in column Q, link_to_metadata
    L. dataset_doi - DOI for the data of the site
    M. contribution_year - year the site was contributed
    N. NOAA_study_id - study identifier, assigned by NOAA
    O. link_to_data - online resource for the FHX data file
    P. link_to_metadata - online resource for complete metadata for the site, 
       in NOAA Template format. 
       Note: this file contains the online resource links for all data and 
       supplemental files including supplemental (tree) data, 
       and fire history graphs depicting the FHX data. 
    Q. link_to_landing_page - link to NOAA landing page for the site