Gray Turnage

Dr. Gray Turnage


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 May 2019 in Drones
Verified
Journal Article
Open access
PDF file
Sathishkumar SamiappanSathishkumar Samiappan
Sathishkumar Samiappan
LHLee Hathcock
Lee Hathcock
GTGray Turnage
Gray Turnage
CMCary McCraine
Cary McCraine
JPJonathan Pitchford
Jonathan Pitchford
RMRobert James Moorhead
Robert James Moorhead
Wildfires can be beneficial for native vegetation. However, wildfires can impact property values, human safety, and ecosystem function. Resource managers require safe, easy to use, timely, and cost-effective methods for quantifying wildfire damage and regeneration. In this work, we demonstrate an approach using an unmanned aerial system (UAS) equipped with a MicaSense RedEdge multispectral sensor to classify and estimate wildfire damage in a coastal marsh. We collected approximately 7.2 km2 of five-band multispectral imagery after a wildfire event in February 2016, which was used to create a photogrammetry-based digital surface model (DSM) and orthomosaic for object-based classification analysis. Airborne light detection and ranging data were used to validate the accuracy of the DSM. Four-band airborne imagery from pre- and post-fire were used to estimate pre-fire health, post-fire damage, and track the vegetation recovery process. Immediate and long-term post-fire classifications, area, and volume of burned regions were produced to track the revegetation progress. The UAS-based classification produced from normalized difference vegetation index and DSM was compared to the Landsat-based Burned Area Reflectance Classification. Experimental results show the potential of using UAS and the presented approach compared to satellite-based mapping in terms of classification accuracies, turnaround time, and spatial and temporal resolutions.

20 October 2017 in Drones
Verified
Journal Article
Open access
PDF file
Sathishkumar SamiappanSathishkumar Samiappan
Sathishkumar Samiappan
GTGray Turnage
Gray Turnage
CMCary McCraine
Cary McCraine
JSJoshua Skidmore
Joshua Skidmore
LHLee Hathcock
Lee Hathcock
RMRobert James Moorhead
Robert James Moorhead
This study describes an unmanned aerial system (UAS) method for accurately estimating the number and diameters of harvested Loblolly Pine (Pinus taeda) stumps in a final harvest (often referred as clear-cut) situation. The study methods are potentially useful in initial detection, quantification of area and volume estimation of legal or illegal logging events to help estimate the volumes and value of removed pine timber. The study sites used included three adjacent pine stands in East-Central Mississippi. Using image pattern recognition algorithms, results show a counting accuracy of 77.3% and RMSE of 4.3 cm for stump diameter estimation. The study also shows that the area can be accurately estimated from the UAS collected data. Our experimental study shows that the proposed UAS survey method has the potential for wide use as a monitoring or investigation tool in the forestry and land management industries.

14 January 2026 in Microplastics
Verified
Journal Article
Open access
PDF file
ENEbenezer Nyadjro
Ebenezer Nyadjro
JCJust Cebrian
Just Cebrian
TCT. Erin Cox
T. Erin Cox
Zhankun WangZhankun Wang
Zhankun Wang
YLYee Lau
Yee Lau
JWJennifer A.B. Webster
Jennifer A.B. Webster
The global proliferation of plastics and their degradation into microplastics (<5 mm) have created a pervasive environmental crisis with severe ecological and human health consequences. Despite the exponential growth in microplastic research over the past decade, standardized protocols are still lacking. The absence of consistent sampling, analysis, and reporting methods limits data comparability, interoperability, and harmonization across studies. This study conducted a systematic bibliographic review of 355 peer-reviewed articles published between 2010 and 2022 that investigated microplastics in freshwater as well as marine water and sediment environments. The goal was to evaluate methodological consistency, sampling instruments, measurement units, reported characteristics, and data-sharing practices to identify pathways toward harmonized and FAIR (Findable, Accessible, Interoperable, and Reusable) microplastic data. Results show that 80.6% of studies focused on marine environments, 18% on freshwater, and 1.4% on both. This highlights persistent data gaps in freshwater systems, which function as key transport pathways for plastics to the ocean. Most studies targeted water (59%) rather than sediment (41%) and were mostly based on single-time sampling, limiting long-term analyses. Surface layers (<1 m) were predominantly sampled, while deeper layers remain understudied. Nets, particularly Manta, neuston, and plankton nets were the dominant tools for water sampling, whereas grabs, corers, and metallic receptacles were used for sediments. However, variations in mesh size and sampling depth introduce substantial biases in particle size recovery and reduce comparability across studies. The most common units were counts/volume for water and counts/g dry weight for sediments, but more than ten unit expressions were identified, complicating conversions. Only 35% of studies reported all four key microplastic characteristics (color, polymer type, shape, and size), and less than 20% made datasets publicly available. To advance harmonization, we recommend the adoption of consistent measurement units, mandatory reporting of key metadata, and wider implementation of open data practices aligned with the FAIR principles. These insights provide a foundation for developing robust monitoring strategies and evidence-based management frameworks. This is especially important for freshwater systems, where data remain scarce, and policy intervention is urgently needed.

17 April 2019 in Invasive Plant Science and Management
Verified
Journal Article
Closed access
PDF file
GTGray Turnage
Gray Turnage
JMJohn D. Madsen
John D. Madsen
RWRyan M. Wersal
Ryan M. Wersal
JBJohn D. Byrd
John D. Byrd
Flowering rush (Butomus umbellatus L.) is an invasive aquatic and wetland plant capable of developing monotypic stands in emergent and submersed sites. This plant can rapidly outcompete native vegetation and impede human practices by reducing recreation (boating, fishing, and skiing) and disrupting agricultural use of water resources (irrigation canals). Mechanical removal practices occurring biweekly, monthly, bimonthly, and once per growing season were compared with chemical control with diquat applied sequentially at 0.19 ppmv ai for two consecutive months over 2 yr (2016 and 2017). Biweekly removal gave the most consistent control of B. umbellatus biomass and propagules. Diquat application along with monthly and bimonthly clippings gave varying degrees of B. umbellatus control. Clipping once per growing season did not control B. umbellatus when compared with reference plants, while clipping B. umbellatus every 2 wk (biweekly) controlled rush propagules most effectively. However, it is unlikely this method will be sufficient as a stand-alone control option due to the slow speed of harvester boats, the potential these boats have to spread B. umbellatus propagules to more sites, and the expense of mechanical operations. However, clipping could be used as part of an integrated strategy for B. umbellatus control.

21 January 2022 in Invasive Plant Science and Management
Verified
Journal Article
Closed access
PDF file
GTGray Turnage
Gray Turnage
JBJohn D. Byrd
John D. Byrd
JMJohn D. Madsen
John D. Madsen
Globally, M. x giganteus is used as a biofuel crop due to its ability to persist in a wide range of climates. However, little work has assessed M. x giganteus ability to invade and persist in wetland habitats. In outdoor mesocosms, we examined M. x giganteus ability to grow in simulated wetland vs. upland habitats and examined chemical control strategies for both habitats using aquatic labeled herbicides. M. x giganteus growth was consistently greater in simulated wetland habitats with wetland plants 2.4 to 3 times taller than upland plants six weeks after treatment (WAT) and 2.8 to 3.3 times taller than upland plants 12 WAT. M. x giganteus aboveground (AG) biomass was 12.7 to 17.7 times greater in wetland versus upland grown plants six WAT and 9.6 to 12.5 times greater 12 WAT. Belowground (BG) biomass was 4.5 to 10.7 times greater in wetland versus upland grown plants six WAT and 4.0 to 6.1 times greater 12 WAT. M. x giganteus BG biomass was always greater than AG in both habitats six (6.0 times greater in wetlands and 2.9 times greater in uplands) and 12 WAT (3.8 times greater in wetlands and 1.3 times greater in uplands). Generally, all herbicide treatments reduced M. x giganteus height (66 to 100% reduction) and biomass (84 to 100%) compared to non-treated plants 12 WAT, however, glyphosate (5,716.3 g a.i. ha-1) and imazapyr (1,120.8 g a.i. ha-1) performed better than imazamox (560.4 g a.i. ha-1) and penoxsulam (98.6 g a.i. ha-1). This is the first work to provide evidence that M. x giganteus can be chemically controlled in wetland habitats. Furthermore, this is the first work to show that penoxsulam (an ALS inhibiting herbicide) can reduce M. x giganteus growth in upland or wetland habitats.

1 January 2024 in Journal of Aquatic Plant Management
Verified
Journal Article
Closed access
ALAdrian Lazaro-Lobo
Adrian Lazaro-Lobo
GTGray Turnage
Gray Turnage
KCKennedy Calhoun
Kennedy Calhoun
GEGary Ervin
Gary Ervin
Literature describing effective control measures for the floating-leaved plants American lotus (Nelumbo lutea Willd.), white waterlily (Nymphaea odorata Aiton), and watershield (Brasenia schreberi J.F. Gmel.) is minimal as these are usually considered as desirable species. However, floating-leaved plants can cause ecological, economic, and social problems when undergoing demographic expansions, usually following alterations of natural hydrologic cycles. Therefore, a mesocosm trial was conducted to determine the potential of foliar applications of seven aquatic herbicides to reduce abundance of the three target species at maximum and half-maximum label rates. Three of the herbicides (glyphosate, imazamox, and florpyrauxifen-benzyl) provided short- and long-term suppression (.75% reduction) of white waterlily and watershield leaf density or biomass. As a followup trial, field work was conducted using glyphosate, imazamox, and florpyrauxifen-benzyl to determine plant response to these herbicides in a natural setting. All herbicides resulted in long-term (52 wk after treatment) leaf density reduction of white waterlily (64 to 100% reduction) and watershield (46 to 75% reduction; except 2.83 kg ae ha 1 glyphosate) in field sites while the abundance of American lotus increased. Reduction of white waterlily and watershield may have reduced competition thereby favoring higher abundance of lotus. Regardless, long-term (52-wk) reduction of white waterlily and watershield suggest the potential for these herbicides as operational management tools for nuisance populations of these species. Future work should evaluate chemical techniques for control of American lotus, where both timing of leaf emergence and potential interactions with other plant species must be considered in the design of those studies.