Gregg R Davidson

Biographic Data

ID	5598112
NAME	Gregg R Davidson
GIVEN NAMES	Gregg R
FAMILY NAME	Davidson
SIGNATURE	DAVIDSON G R
AFFILIATIONS	University of Mississippi
ORCID	0000-0002-5461-1160
VERIFIED	Yes
TOTAL WORKS	6
TOTAL CITATIONS	7
WORKS AS AUTHOR	6
WORKS AS EDITOR	0
FIRST PUBLICATION YEAR	1999
LATEST PUBLICATION YEAR	2024
H-INDEX	2

Collapse of Pre-Covid-19 Differences in Performance in Online vs. In-Person College Science Classes, and Continued Decline in Student Learning
Open AccessGregg R Davidson, Hong Xiao et al.ARTICLEEducation Sciences2024
Studies comparing student outcomes for online vs. in-person classes have reported mixed results, though with a majority finding that lower-performing students, on average, fare worse in online classes, attributed to the lack of built-in structure provided by in-person instruction. The online/in-person outcome disparity was normative for non-major geology classes at the University of Mississippi prior to COVID-19, but the difference disappeared in…
Element Mobility in Bald Cypress Xylem
Stanley J Galicki, Gregg R Davidson et al.ARTICLETree-Ring Research2008
Trace element mobility in bald cypress (Taxodium distichum) was investigated for a suite of elements using cores from century-old trees from a wetland in Humphreys County, Mississippi. Element mobility was determined by comparing the dendrochemistry of decadal increments over the life span of a tree, and by comparing increments of the same age collected from the same tree during two different seasons. Variability within growth increments at the t…
Accurate Lacustrine and Wetland Sediment Accumulation Rates Determined from 14 C Activity of Bulk Sediment Fractions
Open AccessW G Walker, Gregg R Davidson et al.ARTICLERadiocarbon2007Cited by: 5References: 18
In the absence of identifiable macrofossils in lacustrine sediments, radiocarbon dating must rely on pollen or bulk sediment fractions. Bulk sediment fractions are not generally preferred because they contain an unknown mixture of organic material of variable age, they may contain dead carbon such as lignite that is difficult to eliminate, and material of aquatic origin may be subject to reservoir effects. If the various processes that contribute…
Root-Zone Hydrology
Gregg R Davidson, Brian C Laine et al.ARTICLETree-Ring Research2006
Bald cypress (Taxodium distichum) is known to respond to increases in precipitation with increased radial growth even when rooted in continuously saturated sediments where water is not a growth-limiting factor. Measurements of δ18O, Cl−, 3H and hydraulic head in surface water and shallow groundwater in an oxbow lake-wetland in northern Mississippi show that rapid downward flow of surface water into the root zone is initiated only after precipitat…
Changes in Sediment Accumulation Rate in An Oxbow Lake Following Late 19Th Century Clearing of Land for Agricultural Use
Open AccessGregg R Davidson, Meredith Carnley et al.ARTICLERadiocarbon2004Cited by: 2References: 7
Sediment cores were collected from 2 sites in the forested fringe of an oxbow lake surrounded by land that was converted from forest to agricultural use in the late 19th century. The 2 sampling areas were selected to represent areas of high (West site) and low (East site) current sediment accumulation rates, based on distance from a perennially discharging stream. Modern (post settlement and land clearing) sediment accumulation rates were calcula…
Changes in 14 C Activity Over Time During Vacuum Distillation of Carbon from Rock Pore Water
Open AccessGregg R Davidson, I C Yang et al.ARTICLERadiocarbon1999References: 8
The radiocarbon activity of carbon collected by vacuum distillation from a single partially saturated tuff began to decline after approximately 60% of the water and carbon had been extracted. Disproportionate changes in 14 C activity and δ 13 C during distillation rule out simple isotopic fractionation as a causative explanation. Additional phenomena such as matrix diffusion and ion exclusion in micropores may play a role in altering the isotopic…

Changes in 14 C Activity Over Time During Vacuum Distillation of Carbon from Rock Pore Water
Open AccessGregg R Davidson, I C Yang et al.ARTICLERadiocarbon1999References: 8
The radiocarbon activity of carbon collected by vacuum distillation from a single partially saturated tuff began to decline after approximately 60% of the water and carbon had been extracted. Disproportionate changes in 14 C activity and δ 13 C during distillation rule out simple isotopic fractionation as a causative explanation. Additional phenomena such as matrix diffusion and ion exclusion in micropores may play a role in altering the isotopic…
Changes in Sediment Accumulation Rate in An Oxbow Lake Following Late 19Th Century Clearing of Land for Agricultural Use
Open AccessGregg R Davidson, Meredith Carnley et al.ARTICLERadiocarbon2004Cited by: 2References: 7
Sediment cores were collected from 2 sites in the forested fringe of an oxbow lake surrounded by land that was converted from forest to agricultural use in the late 19th century. The 2 sampling areas were selected to represent areas of high (West site) and low (East site) current sediment accumulation rates, based on distance from a perennially discharging stream. Modern (post settlement and land clearing) sediment accumulation rates were calcula…
Root-Zone Hydrology
Gregg R Davidson, Brian C Laine et al.ARTICLETree-Ring Research2006
Bald cypress (Taxodium distichum) is known to respond to increases in precipitation with increased radial growth even when rooted in continuously saturated sediments where water is not a growth-limiting factor. Measurements of δ18O, Cl−, 3H and hydraulic head in surface water and shallow groundwater in an oxbow lake-wetland in northern Mississippi show that rapid downward flow of surface water into the root zone is initiated only after precipitat…
Accurate Lacustrine and Wetland Sediment Accumulation Rates Determined from 14 C Activity of Bulk Sediment Fractions
Open AccessW G Walker, Gregg R Davidson et al.ARTICLERadiocarbon2007Cited by: 5References: 18
In the absence of identifiable macrofossils in lacustrine sediments, radiocarbon dating must rely on pollen or bulk sediment fractions. Bulk sediment fractions are not generally preferred because they contain an unknown mixture of organic material of variable age, they may contain dead carbon such as lignite that is difficult to eliminate, and material of aquatic origin may be subject to reservoir effects. If the various processes that contribute…
Element Mobility in Bald Cypress Xylem
Stanley J Galicki, Gregg R Davidson et al.ARTICLETree-Ring Research2008
Trace element mobility in bald cypress (Taxodium distichum) was investigated for a suite of elements using cores from century-old trees from a wetland in Humphreys County, Mississippi. Element mobility was determined by comparing the dendrochemistry of decadal increments over the life span of a tree, and by comparing increments of the same age collected from the same tree during two different seasons. Variability within growth increments at the t…
Collapse of Pre-Covid-19 Differences in Performance in Online vs. In-Person College Science Classes, and Continued Decline in Student Learning
Open AccessGregg R Davidson, Hong Xiao et al.ARTICLEEducation Sciences2024
Studies comparing student outcomes for online vs. in-person classes have reported mixed results, though with a majority finding that lower-performing students, on average, fare worse in online classes, attributed to the lack of built-in structure provided by in-person instruction. The online/in-person outcome disparity was normative for non-major geology classes at the University of Mississippi prior to COVID-19, but the difference disappeared in…