Conk1 - Forest Pathology Specimen, Robert Z. Selden Jr.

CRHR: Archaeology

Pathology specimen.

Payment For Ecosystem Services: Rewarding The Landowner Who Conserves The Public Good, Steven H. Bullard, Sarah Fuller

Faculty Publications

It has been said that money doesn’t grow on trees, but any forest landowner or manager will tell you that’s not exactly true— especially when observing a harvesting operation or managing dues from your hunting lease. While timber production and recreation are the most frequently monetized services provided by forests, what about the other goods and services they provide on a continuing basis? Are you or other forest landowners in your area being monetarily rewarded for soil stability, flood control, water filtration, air quality, and the other critical services—known as ecosystem services—provided by forests?

Measuring Building Height Using Point Cloud Data Derived From Unmanned Aerial System Imagery In An Undergraduate Geospatial Science Course, David L. Kulhavy, I-Kuai Hung, Daniel R. Unger, Reid Viegut, Yanli Zhang

Faculty Publications

The use of Unmanned Aerial Systems (UAS), also known as drones is increasing in geospatial science curricula within the United States. Within the Arthur Temple College of Forestry and Agriculture (ATCOFA) at Stephen F. Austin State University, Texas, seniors in the geospatial science program complete capstone projects to evaluate current geospatial technology to investigate complex ecological, social and environmental issues. Under the umbrella of a student initiated and designed senior project, students designed a study to estimate height of buildings with UAS data incorporating UAS data, LP360 and ArcScene programs, and Pictometry web-based interface. Results from a statistical analysis of …

Use Of Altmetrics To Analyze Scholarworks In Natural Resource Management, David L. Kulhavy, R Philip Reynolds, Daniel R. Unger, Matthew W. Mcbroom, I-Kuai Hung, Yanli Zhang

Faculty Publications

Digital preservation of library materials has increased the need for methods to access the documents and contents maintained in digital archives. The use of altmetrics to quantify the impact of scholarly works, including PlumX, is increasing readership by listing articles in reference services. The outreach from the digital repository ScholarWorks at Stephen F. Austin State University (SFASU) highlights the impact within the natural resources community from Digital Commons, Forest Sciences Commons; and from the Natural Products Chemistry and Pharmacognosy Commons. The use of PlumX altmetrics was examined to evaluate usage, impact, and digital audience downloads for the Arthur Temple College …

Reconstruction Of Piñon–Juniper Woodlands In The Sky Islands Of The Davis Mountains, Texas, Usa, Mohammad Bataineh, Brian P. Oswald, Hans M. Williams, Dan Unger, I-Kuai Hung

Faculty Publications

Piñon (Pinus spp. L.)–juniper (Juniperus spp. L.) woodlands’ historical stand structures were recreated to provide reference conditions and document long‐term changes in the Sky Islands of the Davis Mountains, Texas. Restoration of these isolated woodlands requires insights into the range of variability in current and historical stand structures, as well as an understanding of the spatiotemporal establishment and recruitment patterns of tree species. With drastic changes in forests and woodlands of the Southwestern United States widely reported, the main objective of this study was to reconstruct woodland tree temporal and spatial establishment patterns. A stratified random sampling approach was used …

Initial Establishment Success Of Five Forages In An East Texas Loblolly Pine (Pinus Taeda) Silvopasture, Michael Richard, Ken Farrish, Brian P. Oswald, Hans M. Williams, Michael Maurer

Faculty Publications

The establishment at the end of 1 year of five forages was evaluated in a loblolly pine (Pinus taeda L.) silvopasture system. The five forages were: ‘Pensacola” bahiagrass (Paspalum notatum Fluegge), “Texas Tough” bermudagrass (Cynodon dactylon L. Pers.), “Alamo” switchgrass (Panicum virgatum L.), “San Marcos” Eastern gamagrass (Tripsacum dactyloides L.), and a native mix containing 45% “Texas” little bluestem (Schizachyrium scoparium Michx Nash), 15% sand lovegrass (Eragrostis trichodes Nutt. L. Alph. Wood), 15% “Blackwell” switchgrass (Panicum virgatum L.), 10% “Lometa” indiangrass (Sorgastrum nutans L. Nash), 10% “Haskell” sideoats grama (Bouteloua …

Preliminary Flammability Assessment Of Sea Buckthorn From The Netherlands Compared To Known Flammable Shrubs Of The Southern And Western Us, Michael Tiller, Brian P. Oswald, Mathijs Schuijn

Faculty Presentations

Sea buckthorn (Hippophae rhamnoides) is a common coastal species in The Netherlands that potentially burns with extreme energy levels. In this region of Europe that is experiencing increases in wildfire events, the need to gain a greater understanding of energy released when this species burns will improve fire behavior predictions. The objective of this study was to conduct an initial investigation into the foliage flammability of sea buckthorn to a common southern United States native shrub known for its flammability, yaupon (Ilex vomitoria), and two common dominant shrub species in California chaparral, chamise (Adenostoma fasciculatum …

Initial Investigation Of Seasonal Flammability Of Three Invasive East Texas Forest Understory Fuels Using Thermogravimetric Analysis, Mike Tiller, Brian P. Oswald, Alyx Frantzen, Warren Conway, Ikuai Hung

Faculty Publications

East Texas forest understory fuels have become increasingly infested with invasive species which have contributed to greater hazardous fuel loads when combined with decades of fire exclusion and passive management. This study focused on estimating seasonal changes in flammability parameters of invasive yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), and Chinese tallow (Triadica sebifera) using thermogravimetric analysis. Foliage and stem samples were collected in the dormant (February) and growing (August) seasons. Differential thermogravimetric (DTG) and proximate analyses were used to estimate species specific flammability parameters related to relative spontaneous ignition temperature (RSIT), gas-phase maximum …

Initial Investigation Of Seasonal Flammability Of Three Invasive East Texas Forest Understory Fuels Using Thermogravimetric Analysis, Michael Tiller, Brian P. Oswald, Alyx Frantzen, Warren Conway, I-Kuai Hung

Faculty Presentations

East Texas forest understory fuels have become increasingly infested with invasive species which have contributed to greater hazardous fuel loads when combined with decades of fire exclusion and passive management. This study focused on estimating seasonal changes in flammability parameters of invasive yaupon (Ilex vomitoria), Chinese privet (Ligustrum sinense), and Chinese tallow (Triadica sebifera) using thermogravimetric analysis. Foliage and stem samples were collected in the dormant (February) and growing (August) seasons. Differential thermogravimetric (DTG) and proximate analyses were used to estimate species specific flammability parameters related to relative spontaneous ignition temperature (RSIT), gas-phase maximum …

An Integrated Method For Coding Trees, Measuring Tree Diameter, And Estimating Tree Positions, Linhao Sun, Luming Fang, Yuhi Weng, Siqing Zheng

Faculty Publications

Accurately measuring tree diameter at breast height (DBH) and estimating tree positions in a sample plot are important in tree mensuration. The main aims of this paper include (1) developing a new, integrated device that can identify trees using the quick response (QR) code technique to record tree identifications, measure DBH, and estimate tree positions concurrently; (2) designing an innovative algorithm to measure DBH using only two angle sensors, which is simple and can reduce the impact of eccentric stems on DBH measures; and (3) designing an algorithm to estimate the position of the tree by combining ultra-wide band (UWB) …

Activity Level-Predation Risk Tradeoff In A Tadpole Guild: Implications For Community Organization Along The Hydroperiod Gradient, Nicholas C. Schiwitz, Christopher M. Schalk, Daniel Saenz

Faculty Publications

Increasing activity levels permit greater food intake for use towards growth and reproduction, consequently increasing predation risk via increased detection. Larval anurans are models to examine activity level-predation risk tradeoffs, as they occupy a variety of lentic habitats that impose constraints on the distribution and abundance of species. Ephemeral ponds have a low abundance and diversity of predators and as a result tadpole species tend to have high foraging rates for rapid development. Permanent ponds generally possess a greater diversity and abundance of predators and tadpoles inhabiting these locations tend to have low activity rates or chemical defenses to minimize …

Modeling Early Responses Of Loblolly Pine Growth To Thinning In The Western Gulf Coastal Plain Region, Yuhi Weng, J. Grogan, Dean W. Coble

Faculty Publications

Growth response to thinning has long been a research topic of interest in forest science. This study presents the first 3–4 years of response of loblolly pine (Pinus taeda L.) growth to thinning at different intensities. Data were collected from the East Texas Pine Research Project’s region-wide loblolly pine thinning study, which covers a wide variety of stand conditions. Four treatments, light, moderate, and heavy thinning, respectively having 370, 555, and 740 residual trees per hectare after thinning, and an unthinned control, were included. Individual tree diameter at breast height (dbh) and total height were recorded annually for the …

Integration Of Citygreen Landscape Ecological Analysis Into A Capstone Environmental Science Course, David L. Kulhavy, Daniel R. Unger, Reid Viegut, I-Kuai Hung, Yanli Zhang

Faculty Publications

CITYgreen Geographic Information Systems software was used to develop a campus wide cover type map for Stephen F. Austin State University in an environmental science landscape ecology course. The finding indicated an equal division of forest cover type compared to impervious surface of buildings and paved surface. Once the classification was completed, students chose an area for reforestation identified in CITYgreen, while raising funds for the purchase of trees for the project. Before completing the project, students reviewed tenets of landscape ecology, civic ecology education, and benefits of urban forestry. At the completion of the project, students reviewed service-learning aspects …

Comparing Canopy Metric Estimations Using Three Conifer Species In The Netherlands, Alan Duncan Hibler, Brian P. Oswald, Nienke Brouwer, Ester Willemsen, Hans M. Williams

Faculty Publications

A growing concern associated with fire in The Netherlands is estimating the spread of wildfire, however often the data needed to estimate canopy fires are lacking. The primary parameter required is canopy bulk density (CBD), which requires estimations of canopy gap fraction and leaf area index (LAI). The accuracy of three indirect methods of estimating CBD (a densiometer, hemispherical canopy photographs (HCP), and a LI-COR LAI 2200c plant canopy analyzer) was compared for three common tree species in the Netherlands [Scots pine (Pinus sylvestris L.), black pine (Pinus nigra Arnold) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)]. No …

The Effect Of Sodium Chloride On Hybrid Taxodium Selections, Anna Koonce, Edward Bush, David Creech

Faculty Publications

Saltwater intrusion is a major cause of coastal erosion. New hybrid bald cypress species have been shown to exhibit salinity tolerance compared to native bald cypress species. Planting these hybrids, or Nanjing Bot Garden genotype (NBG), trees where their roots can stabilize soil and preserve land may reduce coastal erosion in areas subjected to saltwater intrusion. The purpose of this experiment was to determine whether or not selected bald cypress NBG genotype tree species survive better than native bald cypress trees in areas inundated with saline water. Leaves were harvested, dried and analyzed for their elemental concentration. NBG genotype trees …

Effectiveness Of Plant Species For Removing Atmospheric Ammonia, Marife B. Anunciado, Sheryll B. Jerez, Hans Williams, Joey Bray, Dean W. Coble, Rena Saito

Faculty Publications

Six plant species of Yaupon, Eastern red cedar, American holly, Arizona cypress, Arborvitae and Roughleaf dogwood were utilized to determine their effectiveness in the removal of atmospheric ammonia. All species were exposed to three ammonia levels (1, 5 and 10 ppm) in an environmental chamber. Foliar ammonia content was quantified using an enzymatic technique. The effects of exposure to ammonia on the physiological responses (e.g. photosynthetic activity, stomatal conductance, and transpiration rate) of plants in ambient condition were also determined using an open design photosynthetic gas exchange system. Foliar ammonia content was significantly different among the six plant species (p<0.0001) with Eastern red cedar exhibiting the highest content. The physiological responses differed significantly depending on the plant species and the ammonia treatment level. The photosynthetic response of plants to the presence of ammonia was mixed. At low exposure level, all species except Arborvitae had decreased photosynthetic activity, reducing by as much as 44.5% for Yaupon. At the highest concentration, however, Yaupon’s photosynthetic activity improved by about 10%. Exposure to ammonia caused increased stomatal conductance and transpiration rate on American holly and Arizona cypress, making them more susceptible to water loss.

Move It Or Lose It: Interspecific Variation In Risk Response Of Pond-Breeding Anurans, Philip Matich, Christopher M. Schalk

Faculty Publications

Changes in behavior are often the proximate response of animals to human disturbance, with variability in tolerance levels leading some species to exhibit striking shifts in life history, fitness, and/or survival. Thus, elucidating the effects of disturbance on animal behavior, and how this varies among taxonomically similar species with inherently different behaviors and life histories is of value for management and conservation. We evaluated the risk response of three anuran species—southern leopard frog (Lithobates sphenocephalus), Blanchard’s cricket frog (Acris blanchardi), and green tree frog (Hyla cinerea)—to determine how differences in microhabitat use (arboreal vs …

Positional Precision Analysis Of Orthomosaics Derived From Drone Captured Aerial Imagery, I-Kuai Hung, Daniel Unger, David Kulhavy, Yanli Zhang

Faculty Publications

The advancement of drones has revolutionized the production of aerial imagery. Using a drone with its associated flight control and image processing applications, a high resolution orthorectified mosaic from multiple individual aerial images can be produced within just a few hours. However, the positional precision and accuracy of any orthomosaic produced should not be overlooked. In this project, we flew a DJI Phantom drone once a month over a seven-month period over Oak Grove Cemetery in Nacogdoches, Texas, USA resulting in seven orthomosaics of the same location. We identified 30 ground control points (GCPs) based on permanent features in the …

Weed Control And Overstory Reduction Improve Survival And Growth Of Under‐Planted Oak And Hickory Seedlings, Luke B. Oliver, Jeremy Stovall, Chris E. Comer, Hans Williams, Matt E. Symmank

Faculty Publications

Weed control and overstory reduction are important silvicultural treatments for improving survival and growth of under‐planted oak and hickory seedlings. Mast‐producing trees in the bottomland forests of the blackland prairie and Post Oak Savannah ecoregions of Texas have declined in abundance. Oaks and hickories have been replaced by more shade‐tolerant species, including green ash (Fraxinus pennsylvanica Marshall) and sugarberry (Celtis laevigata Willd.), which do not produce significant hard mast for priority wildlife species. A split‐plot experiment design was installed on three sites at Richland Creek Wildlife Management Area in Freestone County, Texas, studying the effects of canopy coverage …

Variation In Carbon Concentrations And Allocations Among Larix Olgensis Populations Growing In Three Field Environments, Jiang Ying, Yuhi Weng, Brian P. Oswald, Hanguo Zhang

Faculty Publications

Key message Variation in carbon concentration among Larix olgensis A. Henry provenances and tree tissues was significant, suggesting importance of such variation to carbon stock calculation. Provenance variation in carbon allocation was only significant in allocations to some tissues, including stem wood, and was strongly site-specific. Some allocation patterns correlated significantly with provenance growth and were related to geographic/climatic variables at the provenance origins.

Context Understanding variation in carbon concentrations and allocations to tree tissues among genetic entries is important for assessing carbon sequestration and understanding differential growth rates among the entries. However, this topic is poorly understood, in particular …

Correlates Of Snake Entanglement In Erosion Control Blankets, Sarah E. Ebert, Kasey L. Jobe, Christopher M. Schalk, Daniel Saenz, Cory K. Adams, Christopher E. Comer

Faculty Publications

In road construction projects across the United States, erosion control methods (e.g., erosion control blankets [ECBs]), are mandated to stimulate seedbed regeneration and prevent soil loss. Previous reports have suggested that snakes are vulnerable to entanglement in ECBs. We conducted a literature review, field surveys, and an entanglement experiment to examine what factors increase a snake’s risk of ECB entanglement. Our literature review produced reports of 175 reptiles entangled in mesh products, 89.1% of which were snakes, with 43.6% of snake entanglements occurring in erosion control products. During our field surveys, we found 10 entangled snakes (n = 2 alive; …

Temporal Changes In Fruit Production Between Recurrent Prescribed Burns In Pine Woodlands Of The Ouachita Mountains, Tamara B. Wood, Christopher E. Comer, Roger W. Perry, Brian P. Oswald

Faculty Publications

The use of prescribed fire is integral to the restoration of open woodlands and savannas, including shortleaf pine (Pinus echinata) woodlands in the Ouachita Mountains of Oklahoma and Arkansas. Fire offers many potential benefits to numerous wildlife; however, short-term implications for understory fruit production are not fully understood, especially in stands subjected to frequent, recurrent burns. We examined the effects of dormant season prescribed burns on woody fruit production (kg ha−1) and fruit producing vegetative cover in the understory of restored pine woodlands. We inventoried 32 stands during four temporal periods after dormant season prescribed fires: 1, 2, …

Individual Tree And Stand-Level Carbon And Nutrient Contents Across One Rotation Of Loblolly Pine Plantations On A Reclaimed Surface Mine, Hannah Z. Angel, Jeremy S. Priest, Jeremy P. Stovall, Brian P. Oswald, Hans M. Williams

Faculty Publications

While reclaimed loblolly pine (Pinus taeda L.) plantations in east Texas, USA have demonstrated similar aboveground productivity levels relative to unmined forests, there is interest in assessing carbon (C) and nutrients in aboveground components of reclaimed trees. Numerous studies have previously documented aboveground biomass, C, and nutrient contents in loblolly pine plantations; however, similar data have not been collected on mined lands. We investigated C, N, P, K, Ca, and Mg aboveground contents for first-rotation loblolly pine growing on reclaimed mined lands in the Gulf Coastal Plain over a 32-year chronosequence and correlated elemental rates to stand age, stem …

Student Led Area Measurement Assessments Using Virtual Globes And Pictometry Web-Based Interface Within An Undergraduate Spatial Science Curriculum, David Kulhavy, I-Kuai Hung, Daniel Unger, Yanli Zhang

Faculty Publications

The use of Virtual Globes and Pictometry continues to expand and develop in undergraduate spatial science education. Spatial science undergraduates measured the area of 30 rectangles on the earth’s surface and compared them to Pictometry hyperspectral imagery measurements within a web-based interface and the Google Earth interface compared to ArcGIS Explorer, Map Developers and ArcMap using the ArcMap 10.5.2 interface. An analysis of variance of the absolute mean area errors (p-value of 0.009271) concluded the accuracy of the five area measurements were statistically different at the 95% confidence interval. A Tukey pair-wise test found that the Pictometry and Google Earth …

Forest Measurements, Yuhi Weng

Faculty Publications

Forest measurements, one of the cornerstones in the foundation of forestry, is the art and science of providing the quantitative information about trees and forest stands necessary for forest management, planning, and research. The updated edition (sixth edition) of this longstanding classic textbook, Forest Measurements, provides new and complete coverage of conventional and current measurement practices and technological applications that link the role of forest measurements with management of forest resources.

Resin Flow In Loblolly And Shortleaf Pines Used By Red-Cockaded Woodpeckers, David L. Kulhavy, W G. Ross, J H. Sun, Daniel Unger, I-Kuai Hung, Richard N. Conner

Faculty Publications

We measured resin flow in loblolly (Pinus taeda L.) and shortleaf (Pinus echinata Mill.) pines in stands used by red-cockaded woodpecker, Picoides borealis (Vieillot), in the Angelina and Davy Crockett National Forests in eastern Texas. We also measured resin flow in a mature loblolly pine stand not used by the woodpeckers. Resin flow varied by study area, species, and stand position. In woodpecker stands, pines experiencing low levels of competition seemed better able to tolerate the continual resin drainage associated with red-cockaded woodpecker resin well pecking. In the Angelina National Forest, all new cavity trees excavated during the study were …

Distribution Of Contaminants In The Environment And Wildlife Habitat Use: A Case Study With Lead And Waterfowl On The Upper Texas Coast, Brian Kearns, Stephen Mcdowell, Jena A. Moon, Elizabeth Rigby, Warren C. Conway, David A. Haukos

Faculty Publications

The magnitude and distribution of lead contamination remain unknown in wetland systems. Anthropogenic deposition of lead may be contributing to negative population-level effects in waterfowl and other organisms that depend on dynamic wetland habitats, particularly if they are unable to detect and differentiate levels of environmental contamination by lead. Detection of lead and behavioral response to elevated lead levels by waterfowl is poorly understood, but necessary to characterize the risk of lead-contaminated habitats. We measured the relationship between lead contamination of wetland soils and habitat use by mottled ducks (Anas fulvigula) on the Upper Texas Coast, USA. Mottled …

A New Site Index Model For Intensively Managed Loblolly Pine (Pinus Taeda) Plantations In The West Gulf Coastal Plain, Kynda R. Trim, Dean W. Coble, Yuhi Weng, Jeremy P. Stovall, I-Kuai Hung

Faculty Publications

Site index (SI) estimation for loblolly pine (Pinus taeda L.) plantations is important for the successful management of this important commercial tree species in the West Gulf Coastal Plain of the United States. This study evaluated various SI models for intensively managed loblolly plantations in the West Gulf Coastal Plain using data collected from permanent plots installed in intensively managed loblolly pine plantations across east Texas and western Louisiana. Six commonly used SI models (Cieszewski GADA model, both Chapman-Richards ADA and GADA models, both Schumacher ADA and GADA models, and McDill-Amateis GADA model) were fit to the data and compared. …

Integrating Drone Technology With Gps Data Collection To Enhance Forestry Students Interactive Hands-On Field Experiences, Daniel Unger, I-Kuai Hung, Yanli Zhang, David Kulhavy

Faculty Publications

Undergraduate students pursuing a Bachelor of Science in Forestry (BSF) at Stephen F. Austin State University (SFA) within the Arthur Temple College of Forestry and Agriculture (ATCOFA) attend an intensive 6-week hands-on instruction in applied field methods. The second week of field station is focused on land measurement activities to introduce students to practical, hands-on, and technology based ways to survey forest boundaries. On Monday of the second week students are introduced to the concepts of how to use a handheld compass to navigate from point to point, use a consumer-grade handheld Global Positioning System (GPS) unit for collecting the …

Site Factors Influence On Herbaceous Understory Diversity In East Texas Pinus Palustris Savannas, Brooke Mccalip, Brian Oswald, Kathryn R. Kidd, Yuhi Weng, Kenneth Farrish Phd

Faculty Publications

Longleaf pine (Pinus palustris) savannas were once dominant across the southeastern U.S., including East Texas and parts of western and central Louisiana. The diverse understory associated with these historical savannas may occasionally be seen today, but not often in longleaf pine ecosystems. This project aimed to define east Texas site characteristics that are necessary to support these ecosystems with a dense and diverse herbaceous understory with little to no midstory cover. Fifty-nine plots across three study sites were established to evaluate the influence of overstory cover, basal area, aspect, elevation, and slope on the number of plant genera present. Forest …