Hyperspectral images were taken from March till October, 2018, of southwestern white pine (Pinus strobiformis), SWWP, seedlings of ten different seed-source families. Half of the seedlings were inoculated with white pine blister rust (Cronartium ribicola). Visual assessments of vigor coincided with hyperspectral data acquisition.
The aim of the experiment was...
The portability and reduced price of unmanned aerial systems (UAS) in recent years has led to a broad range of new UAS-enabled scientific inquiries, including for forestry. Small, consumer-grade UAS are advantageous for forest measurements due to their portability, ease and safety of deployment, and notably, they are currently the...
Stored non-structural carbohydrates (NSCs) could play an important role in tree survival in the face of a changing climate and
associated stress-related mortality. We explored the effects of the stomata-blocking and defoliating fungal disease called
Swiss needle cast on Douglas-fir carbohydrate reserves and growth to evaluate the extent to which...
Full Text:
. Voelker4,
Barbara Lachenbruch1 and Kristen Falk3
1Department of Forest Ecosystems and Society, Oregon
The climate of the Pacific Northwest is in flux, and existing forest ecosystems are stressed and poised to shift in fundamental ways, with or without human intervention. This dissertation probes the nature of forest responses to environmental change through investigations of morphology and genetics of three species of alder co-occurring...
Tree-ring characteristics are commonly used to reconstruct climate variables, but divergence from the assumption of a single biophysical control may reduce the accuracy of these reconstructions. Here, we present data from bur oaks (Quercus macrocarpa Michx.) sampled within and beyond the current species bioclimatic envelope to identify the primary environmental...
Finding trees and crops that are resistant to pathogens is key in preparing for current and future disease threats. In this dissertation, we analyzed the potential of using hyperspectral imaging (HSI) to find infection while identifying issues and strategies addressing differences over time, in spatial resolution, the application of machine...
Leaf hydraulics, gas exchange and carbon storage in Pinus edulis and Juniperus monosperma, two tree species on opposite ends of the isohydry–anisohydry spectrum, were analyzed to examine relationships between hydraulic function and carbohydrate dynamics. Leaf hydraulic vulnerability, leaf water potential (Wl), leaf hydraulic conductance (Kleaf), photosynthesis (A), stomatal conductance (gs)...
Swiss needle cast (SNC) is a fungal disease of Douglas-fir
(Pseudotsuga menziesii) that has recently become prevalent
in coastal areas of the Pacific Northwest. We used growth
measurements and stable isotopes of carbon and oxygen in
tree-rings of Douglas-fir and a non-susceptible reference
species (western hemlock, Tsuga heterophylla) to evaluate...
Vegetation patterns and species distributions are strongly linked to soil moisture regimes, and populations within a species from contrasting climatic regimes could exhibit differences in the degree to which certain functional traits related to establishment are expressed. Tree seedling survival is crucial for forest regeneration, and thus may be a...
Humboldt Redwoods State Park in southern Humboldt County, California is a coastal redwood forest, a highly unique and valued ecosystem. It has many social, cultural, ecological, and economic values, including recreational benefits, heritage and aesthetic values, high biodiversity, nutrient cycling, and climate regulation. However, Humboldt County is at risk of...
