SEASONAL FLAMMABILITY COMPARISONS OF NATIVE AND EXOTIC PLANTS IN THE POST OAK SAVANNAH, BLACKLAND PRAIRIE, AND PINEYWOODS ECOREGIONS OF TEXAS

<p>East Texas’ diverse landscape can present year-round wildfire seasons that can be influenced by seasonal and regional differences in climate and physiography. Greater insight into the fundamental thermal behavior of wildland fuels can aid in fire behavior prediction and development of fire-resistant plant lists. This study focused on estimating seasonal and regional flammability characteristics of five evergreen species: yaupon (<em>Ilex vomitoria</em>), Chinese privet (<em>Ligustrum sinense</em>), greenbrier (<em>Smilax</em> spp.), eastern red cedar (<em>Juniperus virginiana</em>), and escarpment live oak (<em>Quercus fusiformis</em>); and two deciduous species: Chinese tallow (<em>Triadica sebifera</em>) and southern red oak (<em>Quercus falcata</em>). Live foliar and small diameter branch wood samples were collected in the Pineywoods, Post Oak Savannah, and Blackland Prairie Ecoregions during the dormant (February) and growing (August) season. Oxygen bomb calorimetry (OBC) and proximate analyses estimated ash-free net heat content (NHC-AF; MJ kg^-1) and proportions of volatile matter (VM%), fixed carbon (FC%), and ash percent (ash%). Pyrolytic and oxidative thermogravimetric analyses (TGA) estimated model-free activation energies (<em>E_a</em>(s)), relative spontaneous ignition temperature (RSIT; °C), gas-phase maximum mass loss rate (GP-MMLR; % min^-1), and gas-phase combustion duration (GP-CD; min.). Greater mean VM% was a general indicator of greater mean NHC-AF(s) and GP-MMLR(s). All foliar NHC-AF(s), RSIT(s), and GP-MMLR(s) were significantly different with respect to species, season, and ecoregion. Mean regional GP-MMLR(s) were consistently greater in the growing season. The Post Oak Savannah and Blackland Prairie consistently yielded species with the greatest mean NHC-AF(s) and oxidative TGA values. Mean <em>E_a</em>(s) did not present any significant seasonal or regional trends.</p>

Name thesis:degree_name

Doctor of Philosophy - Forestry

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Forestry

Year dc:date.available

2021

Author dc:creator

• Tiller, Michael

Contributors dc:contributor

• Brian P. Oswald
• Alyx S. Frantzen
• I-Kuai Hung

• Wildland Fuel Flammability
• Biomass Thermogravimetric Analysis
• Biomass Heat Content
• Biomass Proximate Analysis
• Chinese Privet
• Chinese Tallow
• Forest Biology
• Other Forestry and Forest Sciences
• Physical Chemistry

Repository record dc:identifier

https://scholarworks.sfasu.edu/etds/417

OAI identifier oai:identifier

oai:scholarworks.sfasu.edu:etds-1450