Date of Award

Summer 8-2021

Degree Type


Degree Name

Master of Science - Forestry



First Advisor

Dr. Brian P. Oswald

Second Advisor

Dr. Kathryn R. Kidd

Third Advisor

Dr. I-Kuai Hung


East Texas forests contain three native pine species known to hybridize when site conditions are suitable. Due to increased gene flow from hybridization, quantifying hybridization spatially is a growing concern as southeastern United States pine forests are increasingly influenced by improved pine genetics and warmer, drier conditions from climate change. High Performance Liquid Chromatography (HPLC) and spatial interpolation using Inverse Distance Weighted were conducted using terpenes extracted from needles of shortleaf pine (Pinus echinata), loblolly pine (Pinus taeda), and putative hybrid individuals sampled in Atlanta State Park, Tyler State Park, and Mission Tejas State Park (n =24; 14 overstory;10 advanced regeneration individuals). Through HPLC, 14 chromatogram peaks were identified and measured for intensity. T-Tests for overstory and advanced regeneration at each site indicated no significant differences for peak intensity between forest strata. Two-way ANOVA indicated the significance of six peaks for the site variable, five peaks for the species class variable, and one peak for their interaction. Tukey HSD tests indicated that the shortleaf pine to shortleaf x loblolly pine comparison was the most consistently significant when mean peak values were compared. From spatial interpolation, peak intensity was generally highest at the northeast, decreasing towards the southwest. Patterns of population scale species differentiation and individual responses to environmental stressors is implied, with increased sample quantity and geographic coverage recommended for more accurate representation. Understanding spatial patterns of species identity and resiliency to environmental stressors is valuable for the sustainable management of forests facing rapidly changing genetic compositions and climatic conditions.

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Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Available for download on Saturday, August 08, 2026



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