Knowledge of stand structure, stand dynamics, and production ecology of species mixtures lags well behind that of single-species, even-aged stands. Two mixed-species spacing trials in central Oregon allowed investigation of mixed-species dynamics in a controlled experimental setting. The first site, Pringle Butte, is a mixture of ponderosa pine (Pinus ponderosa...
Aircraft-based in situ measurements of cirrus cloud ice water content (IWC) are
important for cloud microphysical/radiative modeling and satellite validation studies, yet
the measurements have proven challenging due, in part, to the large dynamic range of
IWC values present in cirrus clouds. To date, three instruments designed for the
measurement...
In the North Atlantic, cold, relatively salty water sinks in the icy Labrador and Greenland seas, forming North Atlantic Deep Water (NADW). This circulates through the global ocean, driving ocean overturning and global heat transport and, thus, impacting global climate. As one of the most climatically sensitive regions on Earth,...
Like other species interactions in ecological systems, host-pathogen interactions are influenced by environmental factors, landscape characteristics and the broader community context. My thesis explores the potential influences of food-web interactions (Chapter 2), climate change (Chapter 3), landscape structure and host movement patterns (Chapter 4), and the combined influences of local...
Subsampling and subsequent imputation of tree heights can improve the predictive performance of stand volume estimation but may also introduce biases. Using coastal Douglas-fir data from southwest Oregon, USA, the predictive performance of several height imputation strategies for estimating stand volume was evaluated. A subsample of 1-15 trees was randomly...
The purpose of this thesis is to increase the positional accuracy of Global Position System (GPS) modules using an artificial intelligence algorithm. Three basic and identical GPS modules were setup in an equilateral triangle formation with side lengths of one meter. The triangle was placed in four separate locations where...
The 2010 Deepwater Horizon oil release posed the challenges of two types of spill: a familiar spill characterized by buoyant oil, fouling and killing organisms at the sea surface and eventually grounding on and damaging sensitive shoreline habitats, and a novel deepwater spill involving many unknowns. The subsurface retention of...
The state of the California Current System (CCS)
since spring 2011 has evolved in response to dissipation
of La Niña through spring and summer, resurgence of
cooler La Niña conditions in fall and winter, and finally
a transition towards ENSO-neutral conditions in spring
2012. The resurgence of La Niña was...
The design of a projectile delivery system often plays a critical role in the durability and breakage patterns associated with spent projectile points. This paper presents the results of an experimental project designed to examine projectile point durability and breakage patterns between three different hafting methods. Specifically, we compare two...
Freshwater ecosystems in the mid- to
upper-latitudes of the northern hemisphere are particularly
vulnerable to the impact of climate change as
slight changes in air temperature can alter the form,
timing, and magnitude of precipitation and consequent
influence of snowmelt on streamflow dynamics. Here,
we examine the effects of hydro-climate,...