@mastersthesis {842, title = {Fire History and Fire Climate Relationships in Upper Elevation Forests of the Southwestern United States}, volume = {Ph.D}, year = {2007}, note = {

Please contact the Laboratory of Tree Ring Research for a copy of this dissertation. The file is too large to be uploaded at this time.

}, pages = {182}, school = {University of Arizona}, type = {Dissertation}, address = {Tucson}, abstract = {

Fire history and fire-climate relationships of upper elevation forests of the southwestern United States are imperative for informing management decisions in the face of increased crown fire occurrence and climate change. I used dendroecological techniques to reconstruct fires and stand-replacing fire patch size in Madrean Sky Islands and Mogollon Plateau. Reconstructed patch size (1685-1904) was compared with contemporary patch size (1996-2004). Reconstructed fires at three sites had stand-replacing patches totaling \> 500 ha. No historical stand-replacing fire patches were evident in the mixed conifer/aspen forests of the Sky Islands. Maximum stand-replacing fire patch size of modern fires (1129 ha) was greater than that reconstructed from aspen (286 ha) and spruce-fir (521 ha). Updated spruce-fir patches may be evidence of larger (\>2000ha) stand-replacing fire patches.

To provide climatological context for fire history I used correlation and regionalization analyses to document spatial and temporal variability in climate regions, and El-Nino Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and the Atlantic Multi-decadal Oscillation (AMO) teleconnections using 273 tree-ring chronologies (1732-1979). Four regions were determined by common variability in annual ring width. The component time score series replicate spatial variability in 20th century droughts (e.g., 1950\’s) and pluvials (e.g., 1910\’s). Two regions were significantly correlated with instrumental SOI and AMO, and three with PDO. Sub-regions within the southwestern U.S. varied geographically between the instrumental (1900-1979) and the pre-instrumental periods (1732-1899). Mapped correlations between ENSO, PDO and AMO, and tree-ring indices illustrate detailed sub-regional variability in teleconnections.

I analyzed climate teleconnections, and fire-climate relationships of historical upper elevation fires from 16 sites in 8 mountain ranges. I tested for links between Palmer Drought Severity Index and tree-ring reconstructed ENSO, PDO and AMO phases (1905-1978 and 1700-1904). Upper elevation fires (115 fires, 84 fire years, 1623-1904) were compared with climate indices. ENSO, PDO, and AMO affected regional PDSI, but AMO and PDO teleconnections changed between periods. Fire occurrence was significantly related to inter-annual variability in PDSI, precipitation, ENSO, and phase combinations of ENSO and PDO, but not AMO (1700-1904). Reduced upper elevation fire (1785-1840) was coincident with a cool AMO phase.

}, keywords = {AMO, climate, dendrochronology, dendroclimatology, ENSO, environment, fire, fire history, forest, madrean sky islands, mogollon plateau, mountain, PDO, southwest, teleconnection, tree ring, upper elevation, Watershed Management}, url = {http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=1375523671\&sid=1\&Fmt=2\&clientId=43922\&RQT=309\&VName=PQD.}, author = {Margolis, Ellis Quinn} } @mastersthesis {521, title = {Fire-Climate-Vegetation Interactions in Subalpine Forests of the Selway-Bitterroot Wilderness Area, Idaho and Montana, USA}, volume = {PhD}, year = {2003}, school = {University of Arizona}, abstract = {The long term patterns of fire-climate interactions and forest recovery processes in subalpine forests are poorly understood. This study used a suite of dendrochronological techniques to identify tree growth-climate relationships, assess the interactions of fire with interannual climate variability, and reconstruct summer temperature in subalpine forests of the Selway-Bitterroot Wilderness Area on the border of Idaho and Montana, USA. Comparison of ring-width chronologies from whitebark pine ( Pinus albicaulis Engelm.) and subalpine larch ( Larix lyallii Parl.) with modern climate data indicated that summer temperatures were most limiting to growth in these conifers. Warm summers were generally conducive to radial growth. However, the temporal stability of the climate-tree growth relationship weakens from the early to later periods of the record. Alterations to growing season length, possibly modified by snow pack, may be related to the reduction in climate-growth relationships. A 748-year reconstruction of average summer temperature was developed that explains [approximate]36\% of the variance of the instrumental record. Positive values of the coefficient of efficiency and reduction of error verification statistics indicated that the reconstruction was of good quality. Warm and cool periods in the reconstruction include a warm decade around the 1650s and prolonged cooling around 1700. Peaks in variance in reconstructed average summer temperature occurred at 87, 15, and 2 years. More than 2000 fire scar and age structure samples were used to evaluate fire-climate relationships. Comparison of widespread fire events to climate variables indicated dry conditions both during the fire year and one year before a fire. Multiple spatial patterns of drought and El Ni{\~n}o were related to widespread fire occurrence. Forest recovery following fires generally proceeds from lodgepole pine ( Pinus contorta var. latifolia Dougl.) toward spruce-fir forests ( Picea engelmannii Parry- Abies lasiocarpa (Hook) Nutt.). Two successional pathways occur, one beginning with an initial lodgepole pine stage, the other a spruce-fir stage. Initial composition was related to the presence of overstory lodgepole pine at the time of fire occurrence as well as the intervals between successive fires. Collectively, these results suggest a strong multi-year drought linkage between climate and fire, and dependence on fire intervals for structuring forest communities.}, keywords = {Geography}, url = {http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=765957031\&sid=4\&Fmt=2\&clientId=43922\&RQT=309\&VName=PQD}, author = {Kipfmueller, Kurt Foster} } @mastersthesis {478, title = {Fire history and stand structure in the Huachuca Mountains of Southeastern Arizona}, volume = {MS}, year = {1998}, school = {University of Arizona}, abstract = {Historically, wildfires in mixed conifer forests of Southwestern sky islands were frequent events. Dendrochronological methods were used to reconstruct fire regimes and stand age structures in the Huachuca Mountains of Southeastern Arizona. Pre-settlement (i.e., before ca. 1870) fire intervals ranged from 4 to 10 years, with many fires spreading over the entire sample area. Stand age distributions show an increase in more shade-tolerant tree species. Although ponderosa pine is still the dominant overstory tree species, recent recruitment is predominantly southwestern white pine and Douglas-fir. Establishment of Ft. Huachuca in 1877 was a precursor to extensive use of timber, mineral, range and water resources in the Huachuca Mountains. The fire regime was altered at this time, with only one subsequent widespread surface fire recorded in 1899. Settlement era land-use practices may be responsible for changes in stand structure and composition.}, url = {http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=738257621\&sid=3\&Fmt=2\&clientId=43922\&RQT=309\&VName=PQD}, author = {Danzer, Shelley Rae} } @mastersthesis {516, title = {Fire History in Riparian Canyon Pine-Oak Forests and the Intervening Desert Grasslands of the Southwest Borderlands: A Dendroecological, Historical, and Cultural Inquiry}, volume = {MS}, year = {1998}, school = {University of Arizona}, address = {Tucson}, abstract = {

Dendroecological, documentary, and ethnoecological evidence were combined to provide an integrated understanding of past natural and cultural fires in the Southwest Borderlands. Fire frequency for the desert grasslands was inferred from synchronous intercanyon fire events. Mean fire intervals range between 4-8 years in canyon pine-oak forests, 4-9 years in the intervening desert grasslands, and 5-9 years in the mixed-conifer forests. Riparian canyon pine-oak forests were important corridors for fire spread between the desert grasslands and higher-elevation forests. The decline of post-settlement (\>1870s) fires typical of most forests in U.S., is not evident south of the border in Mexico.

Documentary evidence reveals the Apache had detailed knowledge of fire, that burning practices were controlled and limited, and ecosystem enhancement through intentional burning was not suggested. However, the common exception was burning practiced during wartime periods, principally by the Apache but also by the Spanish, Mexicans, and later Americans. Fire reconstructions indicate that wartime-period fires were significantly more frequent than peacetime periods at several canyon-rancher{\'I}a sites.

}, keywords = {apache, borderland, cultural, dendrochronology, dendroecological, desert grassland, ethnoecological, fire, fire history, historical, Mexico, oak, peacetime, pine, post settlement, riparian, southwest, spanish, wartime, Watershed Management}, author = {Kaib, J. Mark} } @mastersthesis {439, title = {Fire Histories of Upper Elevation Forests in the Gila Wilderness, New Mexico via Fire Scar and Stand Age Structure Analyses}, volume = {Master of Science}, year = {1997}, pages = {120}, school = {University of Arizona}, address = {Tucson}, abstract = {

Fire-scar analysis to identify fire events and stand age structure analysis to identify fire effects on survivorship of trees were used to reconstruct surface and crown fire regimes in upper elevation forests of the Gila Wilderness, NM. Fire regimes varied across forest type, but not necessarily across elevation. Prior to the twentieth century, (from 1706 to 1904), the mean interval for large fires was 8 years. During the twentieth century, (from 1904 to 1995), the mean fire return interval for large fires was 46 years. The virtual end of historically frequent fire regimes due to livestock grazing and fire suppression since the turn of the century has affected successional pathways of forest types across elevations, favoring later successional forest species and structures.

}, keywords = {dendrochronology, fire, fire regime, fire scar, gila wilderness, new mexico, stand age, suppression, tree ring, upper elevation}, author = {Abolt,Rena Ann Peck} } @mastersthesis {573, title = {Fire History of the Gila Wilderness, New Mexico}, volume = {Master of Science}, year = {1983}, pages = {156}, school = {University of Arizona}, address = {Tucson}, abstract = {

A data base of fire occurrence was established for the Gila Wilderness by analyzing fire scars and compiling fire records. Cross sections of 44 fire scarred ponderosa pine trees (Pinus ponderosa Laws.) were collected from three study areas. Crossdating of more than 800 individual fire scars revealed that extensive surface fires were a common occurrence prior to 1900. Mean fire intervals for a 250-year period prior to 1900 were approximately four to eight years and fire intervals ranged from one to 26 years. Intensive grazing and fire suppression efforts after 1900 resulted in a sudden decrease in number of fires recorded by the sample trees.

A 72-year record (1909-1980) of fire occurrence in the Gila National Forest was compiled from Forest Service records. The fire records and fire scar evidence suggest a need for continued emphasis on fuels reduction and greater flexibility in the Prescribed Natural Fire program.

}, keywords = {crossdate, dendrochronology, fire, fire history, fire scar, gila national forest, gila wilderness, new mexico, pinus ponderosa, ponderosa pine, tree ring}, author = {Swetnam, T.} }