Pseudotsuga menziesii var. menziesii (coast Douglas-fir) is a tree of ecological, economic, and cultural value in its native North American Pacific Northwest (PNW) distribution. P. menziesii is host to a variety of well-documented endophytic foliar microorganisms, including the fungus Nothophaeocryptopus gaeumannii, the causal agent of Swiss needle cast (SNC), and...
Stripe rust (Puccinia striiformis f. sp. tritici) and Septoria tritici blotch (Zymoseptoria tritici) are a constant and significant threat to wheat production, significantly reducing wheat quality and yield. Wheat is responsible for 20% of the world’s human calorie intake, and wheat production must increase to supply the demand of the...
Forest Vegetation Management (VM) is an important tool used in the Pacific Northwest (PNW) for reforestation. It has been well documented that VM increases seedling survival and crop tree volume growth. What is less understood, is how altering the plant community and successional trajectory affects the way the ecosystem uses...
Dual use pasture systems, sometimes referred to as dual purpose pasture systems, take advantage of the land being used to maximize multiple outputs from a single area. Developing a system to support both production of grazing livestock as well as pollinator health is of increasing importance in pasture-based farming systems....
Nutrient limitation constrains tree growth in many managed forests. Nitrogen (N) is the most common limiting nutrient, but high N supply can shift limitation to other nutrients, particularly phosphorus (P) and the base cations calcium (Ca), magnesium (Mg), and potassium (K). As different soil minerals have different capacities to supply...
The electrical grid is a key component of the Nation's critical infrastructure. Its continuous and reliable operation is of vital importance; any system-wide disruption would have a debilitating impact on crucial services, public health and safety, the economy, and the national security of the United States.
High-impact low-frequency events pose...
Seasonal mountain snowpack of the western US (WUS) is a key water resource to millions of people. Impurities at the snow surface directly affect snowmelt timing and rate, as they contribute to earlier peak streamflow, snow disappearance, and less water availability in dry months. Predicting the locations, timing, and intensity...
Within the Pacific Northwest, USA, root diseases of conifers are a major forest health concern. These diseases are primarily caused by basidiomycete fungi. These fungal associates play a vital role in carbon sequestration but also have a significant negative economic impact within the timber industry. As a result, research on...
Technological growth in agriculture increases crop output but it could lower output price in the market. Economic impact assessment in ex-ante analysis usually does not include these indirect supply responses, which can overestimate the economic potential of new technology. This dissertation provides an integrated farm-level ex-ante impact assessment model to...
Streams and rivers play a critical role in global carbon (C) cycling by processing, storing, and transporting C. Headwater streams which make up more than 95% of the length of streams and rivers worldwide have disproportionate influence on fluvial C dynamics. The hyporheic zone (HZ) of headwater streams is a...