2016 Distinguished Alumni Seminar: Professor Randy Dahlgren

On Wednesday, October 5, we are very pleased to welcome Professor Randy Dahlgren (’84, M.S.; ’87, Ph.D.) from the University of California – Davis to give our annual Distinguished Alumni Seminar: “From Subduction to Salmon: Geologic Subsidies Drive High Productivity of a Volcanic Spring-Fed River.” The talk is open to the public and will run from 3:30 to 4:20 p.m. in Anderson 223.

randy-dahlgrenAbout the Speaker
Randy is a Distinguished Professor of Soil Science and Biogeochemistry in the Department of Land, Air and Water Resources at the University of California – Davis, where he holds the Russell L. Rustici Endowed Chair in Rangeland Watershed Sciences. Randy received his Ph.D. and M.S. in forest soils from SEFS (then the College of Forest Resources), and his B.S. in soil science from North Dakota State University. His research program in biogeochemistry examines the interaction of hydrological, geochemical and biological processes in regulating nutrient cycling in terrestrial ecosystems and surface and ground water chemistry. He is a fellow of the Soil Science Society of America, fellow of the UC Davis Agricultural Sustainability Institute, and has received several awards, including the UCD 2008 Academic Senate Distinguished Teaching Award, 2012 UC Davis Prize for Undergraduate Teaching and Scholarly Achievement (considered the UC-Davis Nobel Prize), and the West Lake Friendship Award from the Governor of Zhejiang Province, China.

About the Talk
Critical habitats necessary to support cold-water species in lotic ecosystems are anticipated to diminish as global climate change reduces summertime availability of cold water in streams. Volcanic spring-fed streams may prove an exception to this habitat loss as large aquifers with high residence times produce reliable stream flow for sustaining cold-water species. Here, we identify a hitherto overlooked exceptionally productive and resilient environment in which large groundwater springs located within volcanic arcs provide consistent cold-water stream flow and ecologically significant nitrogen and phosphorus inputs from geologic sources. In the spring-fed Shasta River of northern California, steelhead trout take advantage of abundant food and stable year-round flow and water temperature regimes to accrue a substantial growth advantage over individuals from an adjacent non-spring-fed stream, exhibiting a six-fold increase in mass and two-fold increase in length. Results demonstrate that geologically derived nutrients in spring-fed streams are driving aquatic ecosystem productivity and resiliency, making these habitats exceptionally important for conserving cold-water species impacted by global climate change.

We are thrilled to welcome Randy for the Distinguished Alumni Seminar, and we hope you’ll be able to join us!

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