Recent Topics Posters
Grover, Herbert D. , Pilgrim, Andrew .
Application of tree-ring analysis for quantifying annual growth response of Quercus stellata (Wagenh) to rainfall in Taylor County, Texas.
Quercus stellata(Wagenh) is the dominant oak species in the Cross Timbers oak-forest association found in portions of north-central Texas. This research was conducted in an outlier stand of Q. stellata located approximately 30 km west of the recently mapped western-most distribution of the Cross Timbers association. Tree-ring chronologies developed for Q. stellata in the 1980ís and 1990ís are often used to reconstruct historical climatic trends in the southwest. The results of this research supplements previous regional-scale studies using Q. stellata tree-ring chronologies by providing recent tree-ring data from trees approaching their western-most distributional limits. Also, this study includes data from the drought period of 1998 to 2002 not covered by earlier chronologies. The study site, consisting of an approximately 50 ha mixed stand of Q. stellata and Q. marilandica, is located in southern Taylor County, Texas. A statistically robust sample of two increment cores from each of 26 trees was collected in the fall of 2004. Cores were mounted and prepared in accordance with accepted practices. Ring width measurements to the nearest .001 mm were obtained by scanning increment cores at 2400 dpi and measuring individual ring widths on resultant images using appropriately calibrated image processing software. In accordance with established research protocols in dendrochronology, the software programs COFECHA and ARSTAN were used to evaluate and refine increment core dating, and to obtain detrended growth-ring indices for statistical analysis. Regression analyses revealed statistically significant (p <.05) relationships between ring-width indices and February precipitation of current growing seasons; previous yearís annual precipitation; previous yearís September precipitation; and annual Palmer Drought Severity Index (PDSI) values for the region.
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1 - Hardin-Simmons University, Biology, Box 16165 HSU Station, Abilene, TX, 79698, United States
Presentation Type: Recent Topics Poster
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM