Silvicultural canopy gaps are emerging as an alternative management tool to accelerate development of complex forest structure in young, even-aged forests of the Pacific Northwest. I investigated patterns of nitrogen (N) availability along transects through 0.1 and 0.4 ha silvicultural gaps in three 50-70 year old Douglas-fir forests of western...
Twenty-six Holstein and 18 Jersey multiparous cows in a randomized block design were assigned by calving date and breed to a non-anionic prepartum diet (CTRL) or a treatment diet containing a commercial anionic salt supplement (Animate®). Control and treatment diets were formulated to a dietary anion-cation difference (DCAD) of 21.3...
Tree species directly and indirectly affect soil nutrient cycles. I sought to characterize soils and foliage associated with four common canopy tree species (Douglas-fir, western hemlock, western redcedar, and bigleaf maple) in mixed-species old-growth forests of the Oregon Coast Range and to determine whether and how soils differ among the...
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Steven S. Perakis
Tree species directly and indirectly affect soil nutrient cycles. I
Piliostigma reticulatum and Guiera senegalensis are two native shrubs that
coexist with row crops in parkland systems of the Sahel of Africa. Although
permanently green all year around in soil depleted in nutrients and dry for a nine-month
period, these shrubs have been largely overlooked. Conventional management of these
shrubs...
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Richard P. Dick
Piliostigma reticulatum and Guiera senegalensis are two native shrubs that
Vegetative propagation allows the amplification of selected genotypes for research,
breeding, and commercial planting. However, efficient in vitro regeneration and
genetic transformation remains a major obstacle to research and commercial
application in many plant species. Our aims are to improve knowledge of gene
regulatory circuits important to meristem organization, and...
The primary responsibility of electric utilities is to supply consistent, dependable, and affordable energy to private customers, businesses, and industries. As with many businesses, electric utilities are experiencing the effects of an aging workforce and expending considerable resources to train their current and replacement workers. Community colleges can partner with...
Understanding how N availability influences base cation stores is critical for long-term ecosystem sustainability. Indices of nitrogen (N) availability and the distribution of nutrients in plant biomass, soil, and soil water were examined across ten young, unpolluted Douglas-fir (Pseudotsuga menziesii) stands in the Oregon Coast Range spanning a three-fold soil...
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Steven S. Perakis
Understanding how N availability influences base cation stores is
Fire is a major disturbance process in many forests. Long-term studies of the biogeochemical effects of fires, especially on soils, are very rare.
Consequently, long-term effects of fire on soils are often hypothesized from
short-term effects. In a chronosequence study, I studied 24 western Cascades
(Oregon) forest stands thought to...
This thesis examines the mechanisms that couple the monthly-averaged
atmospheric boundary layer (ABL) to open-ocean sea surface temperature (SST)
perturbations on scales of 50-500 km. The observed positive correlation between
surface wind speed anomalies and SST anomalies is successfully simulated using
the Weather Research and Forecasting (WRF) model.
In numerical...
Many parts of the West are experiencing substantial growth pressures that have increased the demand for water. These new demands come at a time when most of the water in the West has been fully appropriated by traditional uses such as agriculture, mining, and industry. Some attempts are being made...