Desembocadura Río Mitre - ARMIT001 Mundo,Ignacio,A.;Villalba,Ricardo;Veblen,Thomas,T.;Kitzberger,Thomas;Holz,Andrés;Paritsis,J.;Ripalta,Alberto Dating method: crossdated Sample storage location: IANIGLA-CONICET, Laboratorio de Dendrocronología e Historia Ambiental, CCT-CONICET Mendoza, Av Ruiz Leal s/n, M5502IRA Mendoza, Prov. De Mendoza, Argentina, Ignacio Mundo (iamundo@mendoza-conicet.gob.ar, +54 261 5244273) Reference: Mundo,I.A.;Villalba,R.;Veblen,T.T.;Kitzberger,T.;Holz,A.;Paritsis,J.;Ripalta,A. 2017. Fire history in Southern Patagonia: human and climate influences on fire activity in Nothofagus pumilio forests. Ecosphere. DOI: 10.1002/ecs2.1932 Abstract: Fire is a major disturbance affecting forests worldwide with significant economic, social and ecological impacts. The southernmost forests on Earth extend continuously along the Andes from mid- to subantarctic latitudes in South America. In this region, warming and drying trends since the mid-20th century have been linked to a positive trend in the Southern Annual Mode (SAM), the leading mode of extratropical climate variability in the Southern Hemisphere. Due to the scarcity of documentary fire records and the lack of tree-ring fire histories, little is known about how wildfire activity responds to shifts in the westerly circulation pattern and associated climatic variability in the Andean region south of c. 44°S. For the first time, we applied dendrochronological techniques to reconstruct fire history from the angiosperm Nothofagus pumilio at 16 sites distributed from c. 44 to 50oS to determine relationships between fire occurrence and the two primary drivers of wildfire activity: climate variability and human activities. Partial cross-sections with fire-scars were collected from 363 trees in Argentina and Chile. Chronologies of annually resolved fire-scar dates start in 1791 and show a pattern of higher fire frequency during the 20th century, concurrent with the human occupation and colonization processes in southern Patagonia. Years of widespread fire occurring synchronously in two or more disjunct sites are associated with broad-scale climatic anomalies. Intense droughts inferred from extreme departures in temperature, precipitation and the Standardized Precipitation-Evapotranspiration Index (SPEI) during the growing seasons of 1944 and 1962 are consistent with the two most severe fires at northern sites. Extended droughts, reflected by the association of fire occurrence with 6-month cumulative precipitation and SPEI, create conditions for widespread fires at the southern sites (south of c. 46°S). Regional fires were concurrent with significant positive departures of SAM during the austral spring-summer. This tree-ring fire record reveals the influences of both climate variability and human activities on fire in the N. pumilio forests across the Andes, and also establishes the feasibility of using this tree species as a natural archive of fire history. NOAA/IMPD web landing page for this fire history site is available at: https://ncdc.noaa.gov/paleo/study/22517 NOAA/IMPD DIF and JSON metadata records for this fire history site are available at: https://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-fire-22517.xml and https://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/json/noaa-fire-22517.json FHX filename: https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/armit001.fhx IMPD code: ARMIT001 Name of site: Desembocadura Río Mitre Site code: MIT Contributors: Mundo,Ignacio,A.;Villalba,Ricardo;Veblen,Thomas,T.;Kitzberger,Thomas;Holz,Andrés;Paritsis,J.;Ripalta,Alberto Latitude: -50.44739 (WGS84) Longitude: -72.78094 (WGS84) Mean elevation: 311 (meters) Country: Argentina State: Santa Cruz Region: Patagonia First year: 1868 AD Last year: 2011 AD Species name: Nothofagus pumilio [NOPU] Funding agency names and grant numbers: CONICET[PIP 112-2011010-0809],Inter-American Institute for Global Change Research [IAI CRN 2047],National Science Foundation of the United States [0956552, 0966472] Comments: Mundo fire data from Desembocadura Río Mitre, Patagonia - IMPD ARMIT001 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 http://www.fhaes.org for more information.