John R. White
Associate Dean of Research and Professor Louisiana State University
- Baton Rouge LA
Dr. White's research focuses on biogeochemical cycling of carbon, nitrogen and phosphorus in aquatic systems.
Areas of Expertise
Biography
Research Focus
Carbon & Nitrogen Biogeochemistry
Dr. White’s research focuses on carbon, nitrogen, and phosphorus cycling in coastal and freshwater wetlands, estuaries, and lake sediments. He studies constructed-wetland treatment of nutrients and pharmaceuticals, internal nutrient loading, and microbially driven transformations to guide coastal restoration managers—a body of work honored with the National Wetlands Award.
Education
University of Florida
Ph.D.
Soil & Water Science
1999
Florida Institute of Technology
M.S.
Coastal Zone Management
1993
Florida Institute of Technology
M.S.
Geological Oceanography
1992
Washington and Lee
B.S.
Geology
1988
Accomplishments
Coast & Environment Outstanding Faculty Research Award
2015
Fellow, Soil Science Society of America
2017
Dean’s Outstanding Service Award
2018
Media Appearances
Scientists say land is being created at one of two sites on Louisiana's coast
Phys.org online
2022-12-01
White said that the methodologies used to gather data are significant for the state's planned sediment diversions. Wetlands can prove difficult to measure using standard remote sensing techniques, he said, because the rise and subsequent retreat of flood waters make it difficult to determine where land is building, depending on the changing water level.
"Our study in Davis Pond used appropriate remote sensing tools and combined them with over 140 measurements on the soils and plants to provide ground-truthing and certainty for modeling. If a river diversion is affecting the soil, you need to measure the soil, before and after, to fully understand how the river diversion is affecting the land," he said.
Articles
Enriched Molecular-Level View of Saline Wetland Soil Carbon by Sensitivity-Enhanced Solid-State NMR
Journal of the American Chemical Society2024
Soil organic matter (SOM) plays a major role in mitigating greenhouse gas emission and regulating earth’s climate, carbon cycle, and biodiversity. Wetland soils account for one-third of all SOM; however, globally, coastal wetland soils are eroding faster due to increasing sea-level rise. Our understanding of carbon sequestration dynamics in wetlands lags behind that of upland soils. Here, we employ solid-state nuclear magnetic resonance (ssNMR) to investigate the molecular-level structure of biopolymers in wetland soils spanning 11 centuries.
Source and degradation of soil organic matter in different vegetations along a salinity gradient in the Yellow River Delta wetland
Catena2025
Salt marsh wetlands exhibit high carbon capture and storage capabilities, which are crucial for mitigating climate change. However, the mechanisms of soil organic carbon (SOC) sequestration in coastal deltaic salt marsh wetlands are not well understood. To bridge this gap, we present new findings on the distribution, sources, and decomposition of SOC in the Yellow River Delta wetland, focusing on four vegetation types along a salinity gradient: Phragmites australis, Tamarix chinensis, Suaeda salsa, and Spartina alterniflora. The input of litter was found to be the primary factor affecting SOC at the depth from 20 to 100 cm, while microbial degradation and clay content were the main factors in the deeper soil layers between 20 and 100 cm.
Patterns and mechanisms of wetland change in the Breton sound estuary, Mississippi River delta: A review
Estuarine, Coastal and Shelf Science2025
The Breton Sound Estuary, located within the Mississippi River Delta, has experienced significant wetland loss over the past century due to a combination of natural and anthropogenic factors. This study examines the patterns and mechanisms driving wetland change in the upper Breton Sound Basin and focuses on the impacts of riverine isolation, hydrological alterations, and human activities. Prior to human interventions, the basin received regular large riverine input via overbank flooding and crevasse channels. Levee construction began in the 18th century, but it wasn't until the great Mississippi River flood of 1927 that continuous levees were built that completely isolated the river from the upper Breton Sound Basin.
On the calculation of carbon and nutrient transport to the oceans
Scientific Reports2025
Correct estimations of sediment, carbon, and nutrient fluxes are crucial for understanding the impacts of land use, environmental change, and climate change. However, limited measurements—often restricted to surface data or aliased data, i.e., data without repeated observations throughout a tidal cycle—can lead to significant errors in transport calculations, particularly when different water masses interact. To address this issue, our study employed repeated, cross-sectional (cross-channel and through the vertical) measurements of water velocity and concentrations of sediment, carbon, and nutrients over the course of a tidal cycle.
Implications of river reconnection on phosphorus cycling in coastal wetlands
Science of The Total Environment2025
Louisiana's coastal wetlands are experiencing some of the world's largest land loss rates. This problem is partly due to levees along the Mississippi River, isolating the river from the coastal basins. This disconnect prevents delivering of sediment and nutrients to the wetland-dominated coastal basins, where sediments would increase marsh accretion. Louisiana's Coastal Master Plan aims to reconnect the river with riparian areas through construction of a diversion. Baseline phosphorus (P) dynamics were determined before river reconnection and compared to an area with an unmanaged connection to the river.
Affiliations
- United States EPA : Board of Scientific Counselors, Safe and Sustainable Waters
- Soil Science Society of America
- American Geophysical Union
- Society of Wetland Scientists
Media
