Veblen fire data from Laguna Huala Hue - IMPD ARHUA001 Veblen, T.T.; Kitzberger, T.; Villalba, R.; Donnegan, J.A. Veblen, T.T. Kitzberger, T. Villalba, R. Donnegan, J.A. PAGES 2k Network PAGES LOTRED SA2k AUCH Austrocedrus chilensis (D. Don) Pic. Serm. & Bizzarri Chilean cedar cipres de la cordillera Chilean incense cedar earth science/paleoclimate/fire history|tree ring (tree demographic and injury and fire event code,wood,null,null,null,fire history|tree ring,null,null,C,FHX2 data format; refer to IMPD documentation for description of codes) earth science/paleoclimate/fire history|tree ring (age,null,null,null,null,fire history|tree ring,null,null,N,null) earth science/paleoclimate/fire history (Laguna Huala Hue>LATITUDE -41.5>LONGITUDE -71.5) The effects of humans and climatic variation on fire history in northern Patagonia, Argentina were examined by dating fire scars on 458 trees at 21 sites in rain forests of Fitzroya cupressoides and xeric woodlands of Austrocedrus chilensis from 39 to 43 degrees S latitude. Climatic variation associated with fires was analyzed on the basis of 20th-century observational records and tree-ring proxy records of climatic variation since ~1500 A.D. In the Austrocedrus woodlands, fire frequency increases after ~1850 coincident with greater use of the area by Native American hunters. Increased burning, particularly in the zone of more mesic forests, is also strongly associated with forest clearing by European settlers from ~1880 to the early 1900s. The marked decline in fire frequency during the 20th century coincides with both the demise of Native American hunters in the 1890s and increasingly effective fire exclusion. Strong synchroneity in the years of widespread fire at sample sites dispersed over a north-south distance of ~400 km indicates a strong climatic influence on fire occurrence at an annual scale. Tree-ring reconstructions of regional precipitation and temperature show a steeply declining influence of climatic variability on fire occurrence from annual to multi-decadal scales. It is the inter-annual variability in climate, rather than variations in average climatic conditions over longer periods, that strongly influences fire regimes in northern Patagonia. Although climatic variability overrides human influences on fire regimes at an interannual scale, human activity is an equally important determinant of fire frequency at multi-decadal scales. Climatic conditions conducive to widespread fire in both xeric Austrocedrus woodlands and Fitzroya rain forests are typical of the late stages of la Nina (cold phase of the Southern Oscillation) events as indicated by trends in the Southern Oscillation Index and eastern tropical Pacific sea surface temperatures during the 1-2 years before and after fire-event years. Years of extreme fire occurrence are associated both with dry winter-springs of La Nina events and with the warm summers following El Nino events. Years in which the southeast Pacific subtropical anticyclone is intense and located further south than normal are years of enhanced drought and fire. Similarly, years of widespread fire in northern Patagonia are associated with variations in mean sea-level atmospheric pressure at ~50-60 degrees S latitude in the South American-Antarctic Peninsula sector of the Southern Ocean as reconstructed from tree rings for 1746 to 1984. Precipitation, and hence fire regimes, in northern Patagonia are significantly influenced by high-latitude blocking events, which drive westerly cyclonic storms northward. Variations at decadal- to centennial-time scales in major circulation features, such as ENSO activity and the meridionality of regional air flow at high latitudes, as well as changes in the degree of coupling of these feature influence climate and fire regimes of northern Patagonia. STUDY NOTES: *Notice of dataset correction*: on October 31, 2016, the FHX file for this dataset, arhua001.fhx, was corrected. Previous to this correction, (year 1861, column 23) and (year 1871, column 23) both contained '[', which indicates a pith date. As per the recommendation of Dr. Veblen, principal investigator, the first occurrence of the pith date '[' (year 1861, column 23) was changed to '.'. '.' indicates a "null" year - a dated tree ring for which no information on fire history is available, e.g., the ring formed prior to the initial scarring event. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Veblen, T.T. Investigator : Kitzberger, T. Investigator : Villalba, R. Investigator : Donnegan, J.A. 2004-01-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/2396 https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/fire-hist-graphs/arhua001-fire-hist-graph.png https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/fire-hist-graphs/arhua001-fire-hist-graph.pdf https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/arhua001.fhx https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/arhua001.txt https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/fire-hist-graphs/arhua001-fire-hist-graph.png https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/fire-hist-graphs/arhua001-fire-hist-graph.pdf https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/arhua001.fhx https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/arhua001.txt English https://www.ncdc.noaa.gov/paleo/study/2396 https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/fire-hist-graphs/arhua001-fire-hist-graph.png https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/fire-hist-graphs/arhua001-fire-hist-graph.pdf https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/arhua001.fhx https://www1.ncdc.noaa.gov/pub/data/paleo/firehistory/firescar/southamerica/arhua001.txt T.T. Veblen, T. Kitzberger, R. Villalba and J. Donnegan1999Fire history in northern Patagonia: the roles of humans and climatic variationEcological Monographs START YEAR: 1710 AD * END YEAR: 1992 AD -71.5 -41.5 -71.5 -41.5