Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture, and photosynthetic gas exchange and can eventually lead to tree death. To investigate the long-term impacts of dwarf mistletoe on gas exchange of host western hemlock trees, I compared growth, gas...
This thesis consists of three manuscripts describing ecophysiological research on the cyanolichen Lobaria oregana. The first manuscript includes a re-evaluation of the assumptions underlying past estimates of N fixation by this species and provides an estimate of annual N fixation at the Wind River Canopy Crane (WRCC). Based upon litterfall...
Molybdenum is an essential component of biogeochemical cycling, most notably as a component of the nitrogenase enzyme used in biological nitrogen (N) fixation. While the important role of phosphorus (P) in limiting N fixation in ecosystems has been well documented, occurrence and prevalence of molybdenum (Mo) limitation is largely unknown....
In the mountains of central and southern California, high elevation wilderness areas lack epiphytic lichens that can be used to inform us about atmospheric deposition in multiple ways. Epiphytic lichens are capable of accumulating elements proportionally to the local atmospheric concentration, establishing them as commonly used biomonitor of key elements....
Buddleja davidii (butterfly bush) is a highly adaptable landscape plant known for pollinator attraction. Unfortunately, it is also regarded as an invasive plant in highly disturbed environments across the globe. It is an invasive species in Oregon, officially classified as a class B noxious weed in 2004. Currently the state...
Vietnam is considered one of the most climate change-vulnerable countries due to its high dependence on agriculture and its coastal location. Increased atmospheric temperatures caused by climate change also significantly threaten one of Vietnam's most important cash crops, robusta coffee (Coffea canephora). Suitable cultivation sites of robusta, which comprises 97%...