Judith Z Drexler
Biography
EDUCATION
Ph.D., Natural Resouces, Cornell University
M.A. Geography, University of Colorado, Boulder
B.A. Enivronmental Science, University of California, Berkeley
RESEARCH
My work is focused on soil carbon storage and wetland formation processes. In addiiton, I also study the impact of various types of disturbance, including hydrologic alteration, invasive plants, and climate change, on the sustainability of wetland systems. Through the years, I have worked in a variety of ecosystem types including peatlands across the USA, Micronesian mangroves and freshwater swamps, tidal marshes in the San Francisco Estuary and Pacific northwest, and montane fens of the Sierra Nevada.
BACKGROUND
I started out at the US Environmental Protection Agency in the Drinking Water Branch. As I postdoc, I worked at the USDA Forest Service in Honolulu, HI studying hydrologic linkages in coastal wetland complexes in Micronesia. I have been at the US Geological Survey, California Water Science Center since 2000 studying wetland hydrology, biogeochemistry, and ecology in sites across the United States.
Science and Products
Fens as whole-ecosystem gauges of groundwater recharge under climate change
Currently, little is known about the impact of climate change on groundwater recharge in the Sierra Nevada and southern Cascade Range of California or other mountainous regions of the world. The purpose of this study was to determine whether small alpine peat lands called fens can be used as whole-ecosystem gauges of groundwater recharge through...
Drexler, Judith Z.; Knifong, Donna L.; JayLee Tuil; Flint, Lorraine E.; Flint, Alan L. 234U/238U and δ87Sr in peat as tracers of paleosalinity in the Sacramento-San Joaquin Delta of California, USA
The purpose of this study was to determine the history of paleosalinity over the past 6000+ years in the Sacramento-San Joaquin Delta (the Delta), which is the innermost part of the San Francisco Estuary. We used a combination of Sr and U concentrations, d87Sr values, and 234U/238U activity ratios (AR) in peat as proxies for tracking paleosalinity...
Drexler, Judith Z.; Paces, James B.; Alpers, Charles N.; Windham-Myers, Lisamarie; Neymark, Leonid; Bullen, Thomas D.; Taylor, Howard E. Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta
Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward...
Schoellhamer, David H.; Wright, Scott A.; Drexler, Judith Z. Peat formation processes through the millennia in tidal marshes of the Sacramento-San Joaquin Delta, California, USA
The purpose of this study was to determine peat formation processes throughout the millennia in four tidal marshes in the Sacramento-San Joaquin Delta. Peat cores collected at each site were analyzed for bulk density, loss on ignition, and percent organic carbon. Core data and spline fit age-depth models were used to estimate inorganic...
Drexler, Judith Z. Peat Formation Processes Through the Millennia in Tidal Marshes of the Sacramento-San Joaquin Delta, California, USA
The purpose of this study was to determine peat formation processes throughout the millennia in four tidal marshes in the Sacramento-San Joaquin Delta. Peat cores collected at each site were analyzed for bulk density, loss on ignition, and percent organic carbon. Core data and spline fit age-depth models were used to estimate inorganic...
Drexler, J.Z. Peat accretion histories during the past 6,000 years in the marshes of the Sacramento-San Joaquin Delta, CA, USA
The purpose of this study was to determine how vertical accretion rates in marshes vary through the millennia. Peat cores were collected in remnant and drained marshes in the Sacramento–San Joaquin Delta of California. Cubic smooth spline regression models were used to construct age–depth models and accretion histories for three remnant marshes....
Drexler, Judith Z.; Christian S. de Fontaine; Brown, Thomas A. The legacy of wetland drainage on the remaining peat in the Sacramento-San Joaquin Delta, California, USA
Throughout the world, many extensive wetlands, such as the Sacramento-San Joaquin Delta of California (hereafter, the Delta), have been drained for agriculture, resulting in land-surface subsidence of peat soils. The purpose of this project was to study the in situ effects of wetland drainage on the remaining peat in the Delta. Peat cores were...
Drexler, Judith Z.; Christian S. de Fontaine; Steven J. Deverel Peat accretion histories during the past 6,000 years in marshes of the Sacramento-San Joaquin delta, CA, USA
The purpose of this study was to determine how vertical accretion rates in marshes vary through the millennia. Peat cores were collected in remnant and drained marshes in the Sacramento-San Joaquin Delta of California. Cubic smooth spline regression models were used to construct age-depth models and accretion histories for three remnant marshes....
Drexler, Judith Z.; de Fontaine, Christian S.; Brown, Thomas A. The legacy of wetland drainage on the remaining peat in the Sacramento San Joaquin Delta, California, USA
Throughout the world, many extensive wetlands, such as the Sacramento-San Joaquin Delta of California (hereafter, the Delta), have been drained for agriculture, resulting in land-surface subsidence of peat soils. The purpose of this project was to study the in situ effects of wetland drainage on the remaining peat in the Delta. Peat cores were...
Drexler, J.Z.; De Fontaine, C. S.; Deverel, S.J. Evapotranspiration rates and crop coefficients for a restored marsh in the Sacramento-San Joaquin Delta, California, USA
The surface renewal method was used to estimate evapotranspiration (ET) for a restored marsh on Twitchell Island in the Sacramento–San Joaquin Delta, California, USA. ET estimates for the marsh, together with reference ET measurements from a nearby climate station, were used to determine crop coefficients over a 3‐year period during the growing...
Drexler, Judith Z.; Anderson, Frank E.; Snyder, Richard L.
Age Determination of the Remaining Peat in the Sacramento-San Joaquin Delta, California, USA
Introduction The Sacramento-San Joaquin Delta of California was once a 1,400 square kilometer (km2) tidal marsh, which contained a vast layer of peat ranging up to 15 meters (m) thick (Atwater and Belknap, 1980). Because of its favorable climate and highly fertile peat soils, the majority of the Delta was drained and reclaimed for agriculture...
Drexler, Judith Z.; de Fontaine, Christian S.; Knifong, Donna L. South San Francisco Bay tidal marsh vegetation and elevation surveys-Corkscrew Marsh, Bird Island, and Palo Alto Baylands, California, 1983
Changes in the topography and ecology of the San Francisco Bay Estuary ('Estuary') during the past 200 years have resulted in the loss of nearly 80 percent of the historical salt marsh in the region. Currently, numerous projects are being undertaken by federal, state, and local governments in an attempt to restore wetland habitat and ecosystem...
Orlando, James L.; Drexler, Judy Z.; Dedrick, Kent G.