I am examining the factors that drive spatial patterns in soil moisture availability in coniferous forests of the Pacific Northwest. We know that soil moisture controls many ecosystem processes, but we do not understand the factors that control the spatial and temporal variability of soil moisture in watersheds with steep, highly-dissected terrain and shallow soils. Soil characteristics, topography, and inter-annual climate variability play important roles in hydrological function of a hillslope. In my project, I will test how topography influences soil moisture and soil-water retention, modulating forest ecosystem response to seasonal drought and inter-annual variation in climate.
Co-supervised by Dr. Steve Wondzell (USFS PNW Research Station)
After a wildfire, forest soils typically have lowered infiltration capacity and lower erosion thresholds due to changes in soil structure, water-repellency, and removal of surface vegetation and soil organic matter. These often results in changes in peak flows, water yields, and degraded water quality. Additionally, forest managers often use different land use practices to extract economic value and rehabilitate burned forests. However, there are few controlled experiments testing the effectiveness of post-fire land management practices and whether they exacerbate or improve the effects from wildfire alone. My research will determine the effects of wildfire and post-fire land management practices on surface runoff, erosion, and hydrology. In particular, I am addressing the question: Are land management practices such as salvage logging, herbicide application, and subsoiling effective in controlling excess surface runoff and erosion?
I am performing a multiscale investigation of perennial flow and thermal influence of headwater streams into fish bearing systems in Northern California. My research is a collaborative effort between OSU and CalFire.
Co-supervised by Dr. Catalina Segura (OSU)
My research interests focus on the impacts of modern timber-harvesting practices on sources of suspended sediment to headwater streams in the Pacific Northwest. Historically, it is understood that timber-harvesting can increase sediment input to streams through increased hillslope erosion, mass wasting along roads, and increased streambank erosion. However, under modern harvesting practices, the relative importance of each of these sources and their variability throughout the year is poorly understood. Thus, using a sediment fingerprinting approach, I am conducting an investigation of sediment sources in paired watersheds—one of which was recently harvested—in the Oregon Coast Range. A better understanding of these sources could contribute to more effective best management practices for timber harvesting in the future.
My research is directed toward improving our understanding of the fundamental processes and principles of water and nutrient movement through forested watersheds and how these may be impacted by land management activities. I am focusing on spatial and temporal variability of nitrogen and phosphorus concentrations under natural conditions and after disturbances in the Trask Watershed. Through modeling of the relationship between N and P variability and morphometric, soils, geologic, and climatic variables at the catchment scale, controls on nutrient variability under natural and disturbed conditions can be identified. Additionally, natural relationships and potential impacts of increased N and P concentrations due to disturbances on biological parameters (primary producers, macroinvertebrates, stream metabolism) can be quantified.
Co-supervised by Dr. Alba Argerich (OSU)
Stream temperature is fundamental to water quality and is responsible for driving a variety of biotic and abiotic processes in lotic systems. Due to the importance of this physical water quality parameter, there have been many studies regarding changes in the thermal regimes of streams following forest management activities. Additionally, there is also concern about the downstream transmission of heated water, which would increase the spatial extent of thermal effects on aquatic ecosystems. My research is focused on addressing questions related to longitudinal stream temperature dynamics in forested headwater streams and potential responses to forest management activities.
Noah is working for the FEWS Lab as an intern through the College of Forestry Mentored Employment Program. He is an important member of our lab group, assisting faculty and graduate students with research, while gaining field and laboratory knowledge in forest hydrology.
Jerry is working for the FEWS Lab as an intern through the College of Forestry Mentored Employment Program. He is an important member of our lab group, assisting faculty and graduate students with research, while gaining field and laboratory knowledge in forest hydrology.
I'm always interested in hearing from highly motivated, enthusiastic students who are quantitatively minded, field oriented, and able to develop and conduct independent scientific research. Please send me an e-mail if you're interested in joining our group.
Sharon Bywater-Reyes (Post-doc 2015-2017): Assistant Professor, University of Northern Colorado, Greeley, CO
Nicholas A. Cook (Post-doc 2015-2016): Consultant, Otak Engineering, Portland, OR
Cameron Minson (Hydrometric Data Analyst, B.S. 2016-2017): Centro Experimental Forestal (CEFOR), Valdivia, Chile