DOI: 10.25921/eg53-4846
title: NOAA/WDS Paleoclimatology - Bigio fire data from Oninoborsk, Siberia - IMPD RUONI001

description: Every year, millions of hectares burn across Siberia, driven by a combination of warming temperatures, regional drought and human-caused ignitions.  Dendrochronology provides a long-term context to evaluate recent trends in fire activity and interpret the relative influence of humans and climate drivers on fire regimes.  We developed a 400-year record of fire-scarred trees from 17 sites in pine-dominated forests located southeast of Lake Baikal.  Site-level mean fire return intervals (MFI) ranged from 4 – 27 years for all fires and 8 – 35 years for widespread fires within sites.  Sites with the lowest MFI values were located within 1 km of agricultural fields in grassland valleys, suggesting that agricultural burning influenced MFIs at nearby sites.  Fire frequency varied over the record, with significantly high values around 1790, from 1865 to 1880, 1948 to 1955 and 1995 to 2005.  The increased fire activity corresponded with migration waves to the region and major socio-economic change connected with the establishment and breakdown of the Soviet Union.  At broader scales, Superposed Epoch Analysis (SEA) showed that synchronous fire years were associated with regional drought and precipitation deficits.  Wet conditions for two to three years prior to the event year were also significant, suggesting that increased moisture promoted growth of understory fine fuels to support more extensive fires across the study area.  Although fire frequencies increased during the 20th century, fire-climate relationships weakened, suggesting increased human-caused ignitions may override the climate system. Our dataset presents a continuous record of fire over the past 400 years, providing a valuable opportunity to compare dendrochronology-based reconstructions with satellite and documentary records.
description: 
Sample Storage Location: Laboratory of Tree-Ring Research, University of Arizona
Dating Method: crossdated
Related ITRDB_Chronology: Not Applicable

Fire scar data from this site are available in FHX2 format at:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/asia/ruoni001.fhx
along with associated metadata, including links to supplemental information files and Fire History Graphs, at:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/asia/ruoni001-noaa.txt

Fire History Graphs: Fire History Graphs illustrate specific years when fires occurred and how many trees were scarred. They are available in both PDF and PNG formats. The graphs consist of 2 parts, both of which show the X axis (time line) at the bottom with the earliest year of information on the left and the latest on the right. The Fire Index Plot is the topmost plot, and shows two variables: sample depth (the number of recording trees in each year) as a blue line along the left Y axis, compared with the percent trees scarred shown as gray bars along the right Y axis. Below, the Fire Chronology Plot consists of horizontal lines representing injuries by year on individual sampled trees. Symbols are overlain that denote the years containing the dendrochronologically-dated fire scars or injuries. The sample ID of each tree is displayed to the right of each line. The Composite Axis below represents the composite information from all individual series. The symbols used to represent the fire scars or injuries, and the filters used to determine the composite information, are shown in the legend. These graphs were created using the Fire History Analysis and Exploration System (FHAES). See https://www.fhaes.org/ for more information.