Douglas-fir (Pseudotsuga menziesii) is a commercially and ecologically important tree species native to western North America. The foliar pathogens Phaeocryptopus gaeumannii, the causal agent of Swiss Needle Cast, and Rhabdocline species, the causal agents of Rhabdocline needle cast, are two important pathogens specific to Douglas-fir. These pathogens are highly influenced...
Douglas-fir provides social, economic, and ecological benefits in the Pacific Northwest (PNW). In addition to timber, forests support abundant plant and animal biodiversity and provide socioeconomic viability for many rural communities. Products derived from Douglas-fir account for approximately 17% of the U.S. lumber output with an estimated value of $1.9...
Nitrogen (N) fertilizer is a commonly applied silvicultural treatment in intensively managed Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] plantations. When attempting to maximize average growth responses through fertilization, landowners experience difficulty prioritizing stands for treatment based on the likely magnitude of response and return on the operational investment. Field trials were...
In this thesis, we first examine the principle hypotheses behind the improved exotic growth of select timber species, and the evidence for each, with special focus on studies which examine growth between several ranges of a species. We find that literature suggests environmental factors directly tied to net primary production...
Hemlock dwarf mistletoe (Arceuthobium tsugense subsp. tsugense) is an arboreal, hemiparasitic plant that principally parasitizes western hemlock (Tsuga heterophylla). Hemlock dwarf mistletoe exerts a profound influence on infected trees that can drastically change the structure of the tree crown due to reduced growth, top dieback, branch deformation and death, resulting...
Small Unmanned Aircraft Systems (sUASs) equipped with optical sensors are capableof remotely sensing landscapes and wildlife at spatial and temporal resolutions that werepreviously inaccessible due to technical and budgetary limitations. Conventional remotesensing and photogrammetric workflows can be applied to the resulting high resolution imageryto facilitate new types of scientific inquiry....