Randy Dahlgren

Profile image for Randy Dahlgren

Emeritus Faculty

  • Climate Change, Water and Society IGERT
  • Ecology
  • Hydrological Sciences
  • Land Air and Water Resources

Randy Dahlgren is a Professor of Soil Science and Biogeochemistry in the Department of Land, Air and Water Resources.

He is director of the TMDL Research and Technical Support Program, which provides research and technical support for water quality issues in the Sacramento and San Joaquin Rivers.

His principal research interest is watershed-scale biogeochemistry, including interactions of hydrological, geochemical, and biological processes in regulating groundwater and surface water chemistry.

Recent research includes:

  • Rangeland water quality using paired watersheds to examine prescribed fire and grazing effects on nutrients, sediments and pathogens
  • Land use - water quality relationships at the large watershed scale
  • Effects of dams, dam removal and controlled release floods on water quality
  • Effects of floodplain restoration on water quality and lower food web dynamics
  • Hypoxia in the lower San Joaquin River
  • Water quality - food resource dynamics in California rivers
  • Temporal patterns in water quality (inter-annual, seasonal, storm event, diel)
  • Wetlands as a best-management practice for treating irrigation tailwaters
  • Groundwater chemistry in hypersaline Owens Dry Lake
Research Interests & Expertise
  • Biogeochemistry
  • Water Quality

Randy Dahlgren's Recent Projects

Arc of Native Fishes

The Arc project is designed to study how land forms in the Sacramento-San Joaquin Delta interact with freshwater inputs and tides to create habitat favored by native fishes. The investigation focuses on regions in the North Delta where fish surveys have shown relatively high populations of native fishes - regions including Suisun Marsh, the flooded Sherman Island and the Cache and Lindsey sloughs. The areas together form an arc, inspiring the project name "North Delta Arc of Native Fishes."