@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} } @article {765, title = {Radical Growth Losses in Douglas-Fir and White Fir Caused by Western Spruce Budworn in Northern New Mexico: 1700 to 1983}, year = {1985}, note = {Copies of this are available in the Tree Ring Laboratory. Please contact the lab for more information. }, keywords = {budworm, douglas fir, forest, growth loss, new mexico, pest management, report, southwest, spruce, white fir}, author = {United States Department of Agriculture Forest Service Southwestern Region} } @mastersthesis {571, title = {The Effects of Fire Exclusion on Growth in Mature Ponderosa Pine in Northern Arizona}, volume = {Master of Science}, year = {1983}, pages = {28}, school = {University of Arizona}, address = {Tucson}, abstract = {

Dendrochronological techniques were used to assess the effect of fire exclusion on the radial growth of two age classes (approximately 150 to 300 years old) of mature ponderosa pine. Decline in average radial growth in both classes is coincidental with the establishment of a large ponderosa pine seedling crop in 1919 that has since become an extensive stand of stagnant, overcrowded saplings.

F and t tests of tree ring indices comparing the time period before and after 1920 show that growth has significantly declined since 1920 in both age classes. F and t tests comparing the two age classes suggest that growth was similar before 1920, but the older age class shows a significantly stronger growth decline than the younger age class. Spearman Rank Correlation tests indicate that in both groups there was no trend or a tend toward increasing tree ring indices before 1920 in both age classes, but that after 1920 there was a strong, significant trend toward decreasing tree ring indices in both groups, and that the trend is stronger in the older age class. These results suggest that the older trees are experiencing a more pronounced growth suppression effect than the younger trees.

October and July Palmer Drought Severity Indices from 1931 to 1976 were tested for trend toward drought using the Spearman Rank Correlation. There was no trend toward drought during these months, which have the most significant climatic relationship to ponderosa pine growth in northern Arizona. Therefore the growth decline at Chimney Spring may not be attributed to climate.

No environmental factor has changed at Chimney Spring, other than fire exclusion and subsequent seedling establishment. Competition for soil moisture and nutrients, reduced nutrient cycling and soil moisture losses from litter interception may all be factors contributing to the growth decline in the mature ponderosa pines at Chimney Spring.

Key words: age classes, competition, dendrochronology, \“dog-hair\” thickets, fire exclusion, forest, northern Arizona, Pinus ponderosa, radial growth

10-year index:

}, keywords = {age classes, chimney spring, competition, dendrochronology, dog hair thickets, fire, fire exclusion, forest, mature, northern arizona, palmer drought severity indices, pinus ponderosa, ponderosa pine, radial growth, spearman rank correlation}, author = {Sutherland, Elaine Kennedy} } @booklet {752, title = {Forest Damage by Distantly Transported Air Pollution}, note = {Copies of this are available through the Tree Ring Laboratory. Please contact the curator for more information. pcreasman@ltrr.arizona.edu}, keywords = {air pollution, damage, environment, forest, transported} }