Three studies were conducted to evaluate different grazing systems on mixed conifer rangelands in eastern Oregon, and photo points and aerial photography was used to determine effects of 25 years of cattle grazing on stream channel changes and vegetation responses. The first study was designed to determine if grazing treatment...
A three-year investigation was conducted during 1980-1982 to
evaluate the potential of using herded sheep as a silvicultural tool
to suppress brush in Douglas-fir (Pseudotsuga menziesii) plantations
of Oregon's Coast Range. Sheep browsing of Douglas-fir was highest
in May soon after bud break. Averaged over the 2 years of grazing,...
This annotated bibliography was compiled to provide a comprehensive list of sources on the ecological factors that affect forest regeneration. Abstracts from 494 publications are indexed by author, species, and subject, and are arranged into 4 major sections. Topics include the effects of biotic factors, abiotic factors, and stand and...
Because studies of forestry effects on wetlands have been so infrequent in the Pacific Northwest, each section in this report drew heavily from studies of forestry impacts to streams and riparian zones. After assembly and synthesis, that information was extrapolated, mostly in the form of hypotheses, to the very different...
Internal browning (IB) can be a serious problem with the use of modified atmosphere packaging
(MAP) for 'Bartlett' pears (Pyrus communis L.) grown in the Pacific Northwest during storage
and transit to distant markets. To investigate this disorder, 'Bartlett' pears harvested at
commercial maturity were packed in a commercial MAP...
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...
This study describes the composition and structure of forests within the immediate
vicinity of Northern spotted owl (Strix occidentalis caurina) nest sites in the Klamath,
Coast, and Cascade provinces of western Oregon and the Olympic province, Washington.
I compared forest stand data collected at 105 nest sites with data from...
To improve storage/shipping quality of sweet cherry (Prunus avium L.), the effect of calcium chloride (CaCl₂) added to hydro-cooling water on physiological and biochemical processes related to fruit and pedicel quality was investigated on two major cultivars. The fruit tissue Ca content increased up to 29% to 85% logarithmically for...
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‘Sweetheart’) growing in the US Pacific Northwest (PNW). 91
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The Ni-les’tun tidal wetland restoration project in the Coquille River Estuary in southern Oregon is one of the largest and most well-studied tidal restoration projects on the Pacific Northwest coast. However, ecological data on restoration effectiveness and ecosystem change following restoration are relatively rare for projects more than a few...
The freshwater trematode Nanophyetus salmincola has been demonstrated to impair salmonid immune function and resistance to the marine pathogen Vibrio anguillarum, potentially resulting in ocean mortality. We examined whether infection by the parasite N. salmincola similarly increases mortality of juvenile Chinook Salmon Oncorhynchus tshawytscha when they are exposed to the...
Knowledge about the relationship between habitat structure and abundance of a target species
facilitates biodiversity conservation in managed forests. However, modeling the relationship
for infrequent small mammal species in silvicultural experiments introduces the challenge of
excessive zero counts and complex hierarchical sampling. A common solution has been to
ignore infrequent...
The cereal cyst nematode Heterodera avenae reduces wheat yield in the Pacific Northwest. Resistance and tolerance traits among spring wheat cultivars were poorly defined. Screening trials were conducted with 39 cultivars over a 2-yr period in irrigated commercial fields that were infested by H. avenae. Comparisons were made between drill...
Bird-vegetation associations are a base for bird conservation and management, as well as for predictions of the effects of resource management and climate change on wildlife populations. A recent shift in forest management priorities from timber production to native species' habitat conservation on federal lands has emphasized the need to...
Controlling competing vegetation with the application of herbicides and increased seedling size at planting has been shown to increase seedling survival and growth. These two important reforestation tools have often been studied independently of each other, limiting comparisons that can be made between them. This study utilized a factorial treatment...
Early in the establishment of Pacific Northwest conifer plantations, herbaceous weeds often decrease seedling growth through competition for soil moisture during the dry summer months. Critical period studies have reported that reductions in competitive weed cover are necessary during the initial years of establishment to avoid reductions in seedling growth....
Although terrestrial lichens and bryophytes are common in upland plant communities of the Blue
Mountains in northeast Oregon, research on cryptogam communities in this region is wanting. Studies have
shown that lichens and bryophytes can reduce soil erosion and increase soil fertility in other semiarid
habitats of North America. Understanding...
Biological invasions provide a unique opportunity to study the mechanisms that regulate community composition and ecosystem function. Invasive species that are also ecosystem engineers can substantially alter physical features in an environment, and this can lead to cascading effects on the biological community. Aquatic-terrestrial interface ecosystems are excellent systems to...
Two studies were conducted to determine the factors influencing distribution of cattle on northeastern Oregon mixed-conifer forested rangelands. The objective of the first study was the quantification of differences in distribution of cattle of different ages. Beginning in 1991, and continuing through 2001, radio telemetry collars were placed on a...