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Dr. John Madsen
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(530) 752-7870


Area of Expertise:

Research Biologist




Ph.D., University of Wisconsin-Madison, 1986

Work Experience:   

Research Biologist, USDA/ARS, Invasive Species and Pollinator Health Research Unit, Davis, CA, 2014 to present 


Research Focus:

The long-term goal of my research is to develop long-term integrated management approaches to invasive aquatic plants based on an understanding of the life history of that target plant species that results in selective control of the target plant, with minimal environmental impact. This necessitates studies that include:

  1. Understanding the seasonal growth, phenology, and carbohydrate storage patterns of invasive aquatic plant species;
  2. Identifying growth stages of aquatic plants that are significant to the overwintering and propagation of the plant;
  3. Develop use patterns of aquatic herbicides that selectively manage the target plant with minimal impact on native species, and compatible with other management techniques;
  4. Evaluate the environmental impact of both the invasive plant species, and the management techniques used to manage them.
My current research projects include:
  • Phenological and life history studies of water hyacinth, curlyleaf pondweed, Egeria, and flowering rush
  • Chemical control of water hyacinth, Egeria, flowering rush, South American spongeplant, and Ludwigia
  • Environmental drivers for growth of water hyacinth, South American spongeplant, Egeria, and flowering rush
  • Partnering with agencies and research institutions on the development and implementation of invasive aquatic weed management programs


*Info about my research team:

Current lab members include: John Miskella and Christy Morgan

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