Two major objectives were accomplished.
1. A summary of the work done during 1970-71 on a single species intra-specific competition model was written. 2. A multispecies predator-prey model, incorporating the competition mechanism of the single-species model, was developed almost to completion. The single species model is a computer program that...
Published September 1991. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Weeping alkaligrass (Puccinellia distans) and Nuttall’s alkaligrass (Puccinellia
nuttalliana) infest Kentucky bluegrass seed fields of eastern Oregon. Weeping
alkaligrass is an introduced species from Eurasia, whereas Nuttall’s alkaligrass is
native to semi arid environments of western North America. These species are often
referred to collectively as ‘alkaligrass’; however, for farmers...
The effects of harvesting Pacific hake (Merluccius productus)
were examined with a multi-species numerical model composed of
seven logistic growth equations coupled by a food web. The
food web was composed of: California sea lions (Zalophus
californianus), hake, sablefish (Anaplopoma fimbria), spiny
dogfish (Squalus acanthias), a generic rockfish species
(Sebastes...
This study examines the long-term role of interference on stand development of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and red alder (Alnus rubra Bong.) planted mixtures in the Central Cascades of Oregon, USA. The two species are common associates in naturally regenerated and planted conifer stands in the Pacific Northwest. Due...
Biological invasions have been identified as one of the prominent drivers of global environmental change. In particular, invasive predators typically have substantial negative effects on populations of native prey, even driving species to extinction in extreme cases. However, beyond direct predatory effects, little is understood regarding the specific mechanisms by...
Climate-induced range overlap can result in novel interactions between similar species and potentially lead to competitive exclusion. The Western Antarctic Peninsula is one of the most rapidly warming regions on Earth and is experiencing a poleward climate migration. This transition from a polar to sub-polar environment has resulted in a...
The US airline industry is going through a period of consolidation through mergers between leading airlines. A number of recent mergers have been approved by the Antitrust Division of the Department of Justice (DOJ) based on the presence of Southwest Airlines in merger-affected markets. In doing so, the DOJ makes...
Three studies were conducted to characterize and present early-seral
competition between Douglas-fir seedlings and the surrounding vegetation
communities during Pacific Northwest forest establishment. The first experiment
served as the foundation for this dissertation and was designed to quantify tradeoffs
associated with delaying forest establishment activities by introducing a fallow year...