Pacific sardine (Sardinops sagax) in the California Current Ecosystem (CCE) has exhibited extreme sensitivity in its abundance and distribution in the face of decadal-scale climate regime changes. Warm regimes enhance the abundance of Pacific sardine and expand its distribution. Cold regimes lessen the abundance and restrict the distribution. For instance,...
Pacific sardine (Sardinops sagax) in the California Current Ecosystem (CCE) has exhibited extreme sensitivity in its abundance and distribution in the face of decadal-scale climate regime changes. Warm regimes enhance the abundance of Pacific sardine and expand its distribution. Cold regimes lessen the abundance and restrict the distribution. For instance,...
These first measurements of specific surface area (SSA)
of bulk samples of subsurface marine basalts were undertaken
to determine the potential area available for microbial
colonization. SSA ranged from 0.3 to 52 m2/g of basalt
with the lowest value coming from pillow basalt and the
highest value from breccia. The...
1. Ecosystem invasibility is determined by combinations of environmental variables, invader attributes, disturbance regimes, competitive abilities of resident species and evolutionary history between residents and disturbance regimes. Understanding the relative importance of each factor is critical to limiting future invasions and restoring ecosystems.
2. We investigated factors potentially controlling Bromus...
The influence of irrigation frequency (same amount of water per day given at different times) and nitrogen (N) fertilizer rate on water stress [stomatal conductance (gs)], N uptake, and growth (biomass) of container-grown evergreen Rhododendron 'P.J.M. Compact' and 'English Roseum' and deciduous Rhododendron 'Gibraltar' was evaluated. Both N deficiency and...
Determining the causes of vegetation change in arid and semi-arid environments can be difficult and may involve multiple factors, including disturbance, inter-annual climatic variation, soils, effects from years past and interactions between these factors. Theoretical models describing vegetation change in these systems have generally focused on a single aspect as...
The purpose of this dissertation was to demonstrate research scholarship using the American Psychological Association (APA) manuscript-style dissertation format, in accordance with Oregon State University Graduate School and Counseling Academic Unit guidelines.
Chapter 1 provides explanation for how Chapters 2 and 3 are thematically linked manuscripts intended to extend professional...
A study of the effect of mixing on the oxygen uptake rate of
estuarine bottom deposits is presented. The method of study involved
the mixing of samples of bottom deposits with the overlying water to
result in concentrations of suspended matter in the same order as
observed in the estuary....
Annual grass invasion into shrub-dominated ecosystems is associated with changes in nutrient cycling that may alter nitrogen (N) limitation and retention. Carbon (C) applications that reduce plant-available N have been suggested to give native perennial vegetation a competitive advantage over exotic annual grasses, but plant community and N retention responses...