Fishery dependent data--length distributions, sex ratios, maturity schedules, and species composition of landed catches--are necessary for stock assessments. These data are currently collected by state port biologists using a sampling design that randomly selects samples from a small percentage of a very large target population. Sampling programs may need to...
The Boleyn home located in Portland Oregon (latitude 45°) is evaluated based on monitoring data taken from 1977 to 1982. The Boleyn home is a two-story (plus basement) frame home. It takes benefit of passive solar gains and is equipped with an active solar system. The active solar system consists...
Centuries of continuous grain cropping in northern Africa have
reduced N levels in soils to a degree such that agricultural production
is now largely dependent upon nitrogen fertilizer. Through the
identification of highly effective legume and Rhizobium strain combinations,
the production of protein-rich livestock forage and green
manure can be...
Agrobacterium rhizogenes has been shown to cause root
proliferation and increased water use efficiency in
certain woody dicots. Root proliferation may be desirable
in herbaceous legumes as a means of increasing potential
sites for infection by Rhizobium species and subsequent
nodulation and nitrogen fixation. Thus, A. rhizogenes was
used to...
All animals that interact with fishing gear are not necessarily captured, and all animals that are captured are not necessarily retained. Fishing practices and gear configuration, management regulations, and markets dictate which animals ultimately are retained or discarded. The impact of a fishery and the efficacy of management regulations can...
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DavidB. Sampson
All animals that interact with fishing gear are not necessarily captured
Depletion-Based Stock Reduction Analysis (DB-SRA; Dick and MacCall, 2011) is a catch-only fisheries stock assessment model that has been developed to estimate an overfishing limit (OFL) in data-poor situations. DB-SRA projects the biomass trajectories of a stock by means of a catch time series and five parameters: the instantaneous, per...
Sampling error associated with estimates of species composition and age composition
of commercial groundfish landings in Oregon from 1989 to 1991 is documented to evaluate
the impact of variable landing data on fisheries management and monitoring programs. The
statistical reliability and bias associated with two multistage sampling designs are
investigated...
Field experiments were established in 1982 and 1983 on a Woodburn silt loam soil (Aquultic Argixeroll) to examine the effect of S fertilizer on dinitrogen fixation and dry matter yield of 10 week-old seedling alfalfa (Medicago sativa L. cv. 'Apollo'). Six levels of S fertilizer (0 to 67.2 kg S/ha)...
The Sultanate of Oman has 1700 km of coastline extending from the Arabian Gulf
south to the Arabian Sea. The demersal fish distributions and assemblages have not previously
been well defined. In winter, variations in the oceanography of the area are minimal. In
summer, however, the Arabian Sea is strongly...
When biogeochemical models are applied to large regions, the values of key model parameters are often unknowable. Through field and modeling studies, I examined the potential impact of such uncertainty on estimates of carbon cycling in western Oregon. I found that variation in key leaf traits could be interpreted ecologically,...