I am interested in examining scientific problems from the molecular to the field scale and my research approach often requires integration of the disciplines of hydrology, geochemistry and biology. My students typically conduct fieldwork, develop laboratory skills and utilize numerical modeling to investigate a variety of complex biogeochemical processes. Here are some descriptions of current and recently completed research projects
Arsenic in Groundwater in Cambodia
I have been working in Cambodia for about 10 years in partnership with Scott Fendorf’s research group at Stanford University. This work has primarily focused on arsenic contamination to groundwater of the Mekong Delta. The arsenic contamination in the groundwaters of the mega-deltas of Asia represent a massive health threat, impacting an estimated 100 million people. We are conducting a variety of investigations involving hydrology and biogeochemistry to better understand the processes that lead to the release and transport of arsenic in these aquifers.
Nutrient Loading and Impacts in the Lower Boise River
We have been working on characterizing nutrient (particularly phosphorus and nitrate) loading to the Lower Boise River. This work has been conducted by Master’s students Brian Yelen and Ian Penn. Brian focused on better quantifying the inputs to the Boise River using high resolution, synoptic sampling. By collecting and analyzing water samples at high spatial resolution over the entire lower Boise, Brian’s work has demonstrated that discharge from the sewage treatment plants, and not agricultural runoff, is the dominant source of nutrient increases in the Boise River. Ian Penn has conducted research to better understand how elevated levels of phosphorus and nitrate are impacting algal growth. By measuring algal growth on both natural and artificial substrates along the river, Ian has shown that below the sewage treatment plant, algal growth in the river is no longer limited by nutrient concentrations. Ian’s work also shows that tubidity likely limits algal growth in the lowest reaches of the Boise.
The Idaho EPSCoR Grant
The Boise State National Science Foundation EPSCoR, Managing Idaho’s Landscapes for Ecosystem Services (MILES) grant is advancing our understanding of how Idaho’s social and ecological systems will respond to climate change and urban growth. Our goal is to develop science-based support tools to help policy makers sustainably manage Idaho’s resources. I am the Boise State director of this grant. You can learn more about this grant on the Idaho Eco Systems website.
Nitrous Oxide Release From the Hyporheic Zone
This is an NSF supported collaborative grant working with Kevin Feris (Microbiologist, Boise State) and Daniele Tonina (Hydrologist, University of Idaho) to better understand the geochemical, biological and hydrological processes that lead to nitrous oxide, a potent greenhouse gas, release from the bed sediments of streams. This work involves conducting a large flume experiment with in-situ monitoring of water chemistry, microbial genetics and hydraulic parameters. This work is leading to a new conceptual model of nitrous oxide production in these systems. Graduate students Annika Quick is focusing on the geochemistry, Jeff Reeder is working on the hydrology, and Tiffany Farrell is conducting the microbial investigation.
Reynolds Creek Critical Zone Observatory
Boise State is participating in the NSF-funded Reynolds Creek Critical Zone Observatory. We are currently focusing on developing a watershed-scale map of soil carbon distribution; this work is being conducted by graduate Ryan Will. The overall objective is to better understand the controls on the accumulation and loss of soil carbon. Soils store much of the organic carbon on the planet, so knowing how that carbon pool behaves is important to predicting its role as a source or sink under a changing climate.
Dry Creek Experimental Watershed
The Dry Creek Experimental Watershed is located just outside of Boise. We have had many students conduct research in this watershed including projects in hydrology, soils, geomorphology, ecohydrology, and ecology.