%0 Thesis %B Geoscience %D 1983 %T X-ray Densitometric Measurement of Climatic Influence on the Intra-Annual Characteristics of Southern Semiarid Conifer Tree Rings %A Cleaveland, Malcolm %Y Dean, J. %X Annual tree-ring width of Southwestern conifers growing on dry sites exhibits sensitivity to variation in climatically created moisture stress. Douglas-fir, ponderosa pine, and pinyon in the eastern San Juan Basin in northwestern New Mexico and southwestern Colorado were sampled at four sites to investigate covariation of climate with intra-annual anatomy. The sites possessed characteristics that created different amounts of physiological stress in trees. Increment borer samples were glued into wooden mounts and machined to approximately 1.0 mm thickness by a special router-planer. All samples were crossdated by comparing climatically controlled synchronous patterns of ring widths. Moving slit X-ray densitometry (at Forintek Canada Corporation Western Forest Products Laboratory, Vancouver, British Columbia) objectively defined the earlywood zone (large, low density cells) and latewood zone (smaller, denser cells formed late in the growing season) in each ring. The densitometer measured eight parameters for each ring: ring, earlywood, and latewood width, minimum and maximum density, and mean ring, earlywood, and latewood density. Individual radial series were standardized (i.e, transformed to indices with 1.0 mean and homogeneous variance) by fitting curves and dividing annual values by the corresponding curve values. Density series proved more difficult to standardize than widths and usually correlated more poorly among individual radii of the same data type. Statistical characteristics of site summary density chronologies differed from width chronologies. Response functions using monthly mean temperature and total precipitation showed climate influenced all data types. Low moisture stress increased ring, earlywood, and latewood width and ring, maximum, and latewood density. High moisture stress increased minimum and earlywood density. No width or density type consistently covaried more than any other with climate. Linkage of climatic variation with density parameters differed considerably from that reported in the literature for conifers growing in wetter, cooler climates. Southwestern conifers posed unique densitometric technical difficulties. Selection of sites that caused moderate physiological stress and samples with few missing rings proved critical. Acquisition of density data required much more time and effort than optical measurement of ring width, but yielded valuable intra-annual data. Intra-annual densitometric data hold great promise for reconstruction of seasonal paleoclimate. %B Geoscience %I University of Arizona %G eng %U http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=752888331&sid=23&Fmt=2&clientId=43922&RQT=309&VName=PQD %0 Thesis %B Forestry %D 1975 %T Dendroclimatic Relationships of Shortleaf Pine (Pinus Echinat Mill.) in the South Carolina Piedmont %A Cleaveland, Malcolm %X An investigaiton was made of the dendrochronolical and dendroclimatic properties of shortleaf pine (Pinus echinata Mill.) in the western South Carolina Piedmont. Accurate dating of each annual ring was achieved by matching patterns of relatively narrow rings in the trees. Earlywood, latewood, and total annual radial growth were measured. To minimize non-climatic sources of radial growth variation, such as stand disturbance, and make different samples comparable, a computer program fitted an orthogonal polynomial curve to each series of measurements. Values for each year were divided by the curve value for that year. The resulting series were averaged to produce earlywood, latewood, and annual growth final chronologies with means of 1.0 and variances independent of age or mean growth of the trees. High resolution x-radiographs were made of the samples with the moving slit technique and intra-annual density variations were plotted by a scanning optical microdensitometer. Minimum earlywood and maximum latewood densities were measured. A regression line was... %B Forestry %I Clemson University %V MS %G eng %U http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=754053131&sid=1&Fmt=1&clientId=43922&RQT=309&VName=PQD